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* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration.
@ 2022-06-17 21:46 Joshua Branson via Guix-patches via
  2022-06-17 21:54 ` [bug#56046] [PATCH] gnu: services: opensmtpd-records-task-list.org: Some notes about how I thought about building this service. And some additional task lists, as well as the WIP documentation Joshua Branson via Guix-patches via
                   ` (5 more replies)
  0 siblings, 6 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-06-17 21:46 UTC (permalink / raw)
  To: 56046; +Cc: Joshua Branson

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Openmstpd-configuration may only be configured by a config-file.  This
patch, enables one to configure opensmtpd by using some guile record
types (defined via define-record-type*).

This patch is mostly complete, but I could use some guidance on what
else needs to be done for it to be accepted in to guix properly.
I do have some documentation written for the opensmtpd-service,
but it is probably not complete and is currently written in the
org-mode format.                     

* gnu/services/mail.scm (opensmtpd-table-configuration): New record.
* gnu/services/mail.scm (opensmtpd-ca-configuration): New record.
* gnu/services/mail.scm (opensmtpd-pki-configuration): New record.
* gnu/services/mail.scm (opensmtpd-action-local-delivery-configuration): New record.
* gnu/services/mail.scm (opensmtpd-maildir-configuration): New record.
* gnu/services/mail.scm (opensmtpd-mda-configuration): New record.
* gnu/services/mail.scm (opensmtpd-action-relay-configuration): New record.
* gnu/services/mail.scm (opensmtpd-option-configuration): New record.
* gnu/services/mail.scm (opensmtpd-filter-phase-configuration): New record.
* gnu/services/mail.scm (opensmtpd-filter-configuration): New record.
* gnu/services/mail.scm (opensmtpd-listen-on-configuration): New record.
* gnu/services/mail.scm (opensmtpd-listen-on-socket-configuration): New record.
* gnu/services/mail.scm (opensmtpd-match-configuration): New record.
* gnu/services/mail.scm (opensmtpd-smtp-configuration): New record.
* gnu/services/mail.scm (opensmtpd-srs-configuration): New record.
* gnu/services/mail.scm (opensmtpd-queue-configuration): New record.
* gnu/services/mail.scm (opensmtpd-configuration): New record.
---
 gnu/services/mail.scm | 2016 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 2013 insertions(+), 3 deletions(-)

diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index d99743ac31..bdc0ee3bf7 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -57,8 +57,143 @@ (define-module (gnu services mail)
             mailbox-configuration
             namespace-configuration
 
+            opensmtpd-table-configuration
+            opensmtpd-table-configuration?
+            opensmtpd-table-configuration-name
+            opensmtpd-table-configuration-file-db
+            opensmtpd-table-configuration-data
+
+            opensmtpd-ca-configuration
+            opensmtpd-ca-configuration?
+            opensmtpd-ca-configuration-name
+            opensmtpd-ca-configuration-file
+
+            opensmtpd-pki-configuration
+            opensmtpd-pki-configuration?
+            opensmtpd-pki-configuration-domain
+            opensmtpd-pki-configuration-cert
+            opensmtpd-pki-configuration-key
+            opensmtpd-pki-configuration-dhe
+
+            opensmtpd-action-local-delivery-configuration
+            opensmtpd-action-local-delivery-configuration?
+            opensmtpd-action-local-delivery-configuration-method
+            opensmtpd-action-local-delivery-configuration-alias
+            opensmtpd-action-local-delivery-configuration-ttl
+            opensmtpd-action-local-delivery-configuration-user
+            opensmtpd-action-local-delivery-configuration-userbase
+            opensmtpd-action-local-delivery-configuration-virtual
+            opensmtpd-action-local-delivery-configuration-wrapper
+
+            opensmtpd-maildir-configuration
+            opensmtpd-maildir-configuration?
+            opensmtpd-maildir-configuration-pathname
+            opensmtpd-maildir-configuration-junk
+
+            opensmtpd-mda-configuration
+            opensmtpd-mda-configuration-name
+            opensmtpd-mda-configuration-command
+
+            opensmtpd-action-relay-configuration
+            opensmtpd-action-relay-configuration?
+            opensmtpd-action-relay-configuration-backup
+            opensmtpd-action-relay-configuration-backup-mx
+            opensmtpd-action-relay-configuration-helo
+            opensmtpd-action-relay-configuration-domain
+            opensmtpd-action-relay-configuration-host
+            opensmtpd-action-relay-configuration-pki
+            opensmtpd-action-relay-configuration-srs
+            opensmtpd-action-relay-configuration-tls
+            opensmtpd-action-relay-configuration-auth
+            opensmtpd-action-relay-configuration-mail-from
+            opensmtpd-action-relay-configuration-src
+
+            opensmtpd-option-configuration
+            opensmtpd-option-configuration?
+            opensmtpd-option-configuration-option
+            opensmtpd-option-configuration-not
+            opensmtpd-option-configuration-regex
+            opensmtpd-option-configuration-data
+
+            opensmtpd-filter-phase-configuration
+            opensmtpd-filter-phase-configuration?
+            opensmtpd-filter-phase-configuration-name
+            opensmtpd-filter-phase-configuration-phase-name
+            opensmtpd-filter-phase-configuration-options
+            opensmtpd-filter-phase-configuration-decision
+            opensmtpd-filter-phase-configuration-message
+            opensmtpd-filter-phase-configuration-value
+
+            opensmtpd-filter-configuration
+            opensmtpd-filter-configuration?
+            opensmtpd-filter-configuration-name
+            opensmtpd-filter-configuration-proc
+
+            opensmtpd-listen-on-configuration
+            opensmtpd-listen-on-configuration?
+            opensmtpd-listen-on-configuration-interface
+            opensmtpd-listen-on-configuration-family
+            opensmtpd-listen-on-configuration-auth
+            opensmtpd-listen-on-configuration-auth-optional
+            opensmtpd-listen-on-configuration-filters
+            opensmtpd-listen-on-configuration-hostname
+            opensmtpd-listen-on-configuration-hostnames
+            opensmtpd-listen-on-configuration-mask-src
+            opensmtpd-listen-on-configuration-disable-dsn
+            opensmtpd-listen-on-configuration-pki
+            opensmtpd-listen-on-configuration-port
+            opensmtpd-listen-on-configuration-proxy-v2
+            opensmtpd-listen-on-configuration-received-auth
+            opensmtpd-listen-on-configuration-senders
+            opensmtpd-listen-on-configuration-secure-connection
+            opensmtpd-listen-on-configuration-tag
+
+            opensmtpd-listen-on-socket-configuration
+            opensmtpd-listen-on-socket-configuration?
+            opensmtpd-listen-on-socket-configuration-filters
+            opensmtpd-listen-on-socket-configuration-mask-src
+            opensmtpd-listen-on-socket-configuration-tag
+
+            opensmtpd-match-configuration
+            opensmtpd-match-configuration?
+            opensmtpd-match-configuration-action
+            opensmtpd-match-configuration-options
+
+            opensmtpd-smtp-configuration
+            opensmtpd-smtp-configuration?
+            opensmtpd-smtp-configuration-ciphers
+            opensmtpd-smtp-configuration-limit-max-mails
+            opensmtpd-smtp-configuration-limit-max-rcpt
+            opensmtpd-smtp-configuration-max-message-size
+            opensmtpd-smtp-configuration-sub-addr-delim character
+
+            opensmtpd-srs-configuration
+            opensmtpd-srs-configuration?
+            opensmtpd-srs-configuration-key
+            opensmtpd-srs-configuration-backup-key
+            opensmtpd-srs-configuration-ttl-delay
+
+            opensmtpd-queue-configuration
+            opensmtpd-queue-configuration?
+            opensmtpd-queue-configuration-compression
+            opensmtpd-queue-configuration-encryption
+            opensmtpd-queue-configuration-ttl-delay
+
             opensmtpd-configuration
             opensmtpd-configuration?
+            opensmtpd-package
+            opensmtpd-config-file
+            opensmtpd-configuration-bounce
+            opensmtpd-configuration-listen-ons
+            opensmtpd-configuration-listen-on-socket
+            opensmtpd-configuration-includes
+            opensmtpd-configuration-matches
+            opensmtpd-configuration-mda-wrappers
+            opensmtpd-configuration-mta-max-deferred
+            opensmtpd-configuration-srs
+            opensmtpd-configuration-smtp
+            opensmtpd-configuration-queue
+
             opensmtpd-service-type
             %default-opensmtpd-config-file
 
@@ -1651,13 +1786,1888 @@ (define (generate-dovecot-documentation)
 ;;; OpenSMTPD.
 ;;;
 
+;; some fieldnames have a default value of #f, which is ok.  They cannot have a value of #t.
+;; for example opensmtpd-table-configuration-data can be #f, BUT NOT true.
+;; my/sanitize procedure tests values to see if they are of the right kind.
+;; procedure false? is needed to allow fields like 'values' to be blank, (empty), or #f BUT also
+;; have a value like a list of strings.
+(define (false? var)
+  (eq? #f var))
+
+;; this procedure takes in a var and a list of procedures.  It loops through list of procedures passing in var to each.
+;; if one procedure returns #t, the function returns true.  Otherwise #f.
+;; TODO for fun rewrite this using map
+;; If I rewrote it in map, then it may help with sanitizing.
+;; eg: I could then potentially easily sanitize vars with lambda procedures.
+(define (is-value-right-type? var list-of-procedures record fieldname)
+  (if (null? list-of-procedures)
+        #f
+        (cond [(procedure? (car list-of-procedures))
+               (if ((car list-of-procedures) var)
+                   #t
+                   (is-value-right-type? var (cdr list-of-procedures) record fieldname))]
+              [(and (sanitize-configuration? (car list-of-procedures))
+                    (sanitize-configuration-error-if-proc-fails (car list-of-procedures))
+                    (if ((sanitize-configuration-proc (car list-of-procedures)) var)
+                        #t
+                        (begin
+                          (apply string-append
+                                 (sanitize-configuration-error-message (car list-of-procedures)))
+                          (throw 'bad! var))))]
+              [else (if ((sanitize-configuration-proc (car list-of-procedures)) var)
+                        #t
+                        (is-value-right-type? var (cdr list-of-procedures) record fieldname))])))
+
+;; converts strings like this:
+;; "apple, ham, cherry" -> "apple, ham, or cherry"
+;; "pineapple" -> "pinneapple".
+;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
+(define (add-comma-or string)
+  (define last-comma-location (string-rindex string #\,))
+  (if last-comma-location
+      (if (string-contains string ", or" last-comma-location)
+          string
+          (string-replace string ", or" last-comma-location
+                          (+ 1 last-comma-location)))
+      string))
+
+;; I could test for read-ability of a file, but then I would have to
+;; test the program as root everytime instead of as a normal user...
+(define (file-exists? file)
+(if (string? file)
+    (access? file F_OK)
+    #f))
+
+(define (list-of-procedures->string procedures)
+  (define string
+    (let loop ([procedures procedures])
+      (if (null? procedures)
+          ""
+          (begin
+            (string-append
+             (cond [(eq? false? (car procedures))
+                    "#f , "]
+                   [(eq? boolean? (car procedures))
+                    "boolean, "]
+                   [(eq? string? (car procedures))
+                    "string, "]
+                   [(eq? integer? (car procedures))
+                    "integer, "]
+                   [(eq? list-of-strings? (car procedures))
+                    "list of strings, "]
+                   [(eq? assoc-list? (car procedures))
+                    "an association list, "]
+                   [(eq? opensmtpd-pki-configuration? (car procedures))
+                    "an <opensmtpd-pki-configuration> record, "]
+                   [(eq? opensmtpd-table-configuration? (car procedures))
+                    "an <opensmtpd-table-configuration> record, "]
+                   [(eq? list-of-unique-opensmtpd-match-configuration? (car procedures))
+                    "a list of unique <opensmtpd-match-configuration> records, "]
+                   [(eq? table-whose-data-are-assoc-list? (car procedures))
+                    (string-append
+                    "an <opensmtpd-table-configuration> record whose fieldname 'values' are an assoc-list \n"
+                    "(eg: (opensmtpd-table-configuration (name \"table\") (data '(\"joshua\" . \"$encrypted$password\")))), ")]
+                   [(eq? file-exists? (car procedures))
+                    "file, "]
+                   [else "has an incorrect value, "])
+             (loop (cdr procedures)))))))
+  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
+
+;; TODO can I M-x raise-sexp (string=? string var) in this procedure? and get rid of checking
+;; if the var is a string?  The previous string-in-list? had that check.
+;; (string-in-list? '("hello" 5 "cat")) currently works.  If I M-x raise-sexp (string=? string var)
+;; then it will no longer work.
+(define (string-in-list? string list)
+  (primitive-eval (cons 'or (map (lambda (var) (and (string? var) (string=? string var))) list))))
+
+(define (my/sanitize var record fieldname list-of-procedures)
+  (if (is-value-right-type? var list-of-procedures record fieldname)
+      var
+      (begin
+        (display (string-append "<" record "> fieldname: '" fieldname "' is of type "
+                                (list-of-procedures->string list-of-procedures) "\n"))
+        (throw 'bad! var))))
+
+;; Some example opensmtpd-table-configurations:
+;;
+;;  (opensmtpd-table-configuration (name "root accounts") (data '(("joshua" . "root@dismail.de") ("joshua" . "postmaster@dismail.de"))))
+;;  (opensmtpd-table-configuration (name "root accounts") (data (list "mysite.me" "your-site.com")))
+;;  TODO should <opensmtpd-table-configuration> support have a fieldname 'file'?
+;;  Or should I change name to name-or-file ?
+(define-record-type* <opensmtpd-table-configuration>
+  opensmtpd-table-configuration make-opensmtpd-table-configuration
+  opensmtpd-table-configuration?
+  this-record
+  (name opensmtpd-table-configuration-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table-configuration" "name" (list string?)))))
+  (file-db opensmtpd-table-configuration-file-db
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-table-configuration" "file-db"
+                                    (list boolean?)))))
+  ;; FIXME support an aliasing table as described here:
+  ;; https://man.openbsd.org/table.5
+  ;; One may have to use the record file for this.  I don't think tables support a table like this:
+  ;; table "name" { joshua = joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root = root@gnucode.me }
+  ;; If values is an absolute filename, then it will use said filename to house the table info.
+  ;; filename must be an absolute filename.
+  (data opensmtpd-table-configuration-data
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-table-configuration" "values"
+                                   (list file-exists? list-of-strings? assoc-list?)))))
+  ;; is a list of values or key values
+  ;; eg: (list "mysite.me" "your-site.com")
+  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" . "james@gnu.org"))
+  ;; I am currently making these values be as assocation list of strings only.
+  ;; FIXME should I allow a var like this?
+  ;; (list (cons "gnucode.me" 234.949.392.23))
+  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
+  ;; (opensmtpd-table-configuration-type record) returns the values' type.  The user SHOULD NEVER set the type.
+  ;; TODO jpoiret: on irc reccomends that I just use an outside function to determine fieldname 'values', type.
+  ;; it would be "simpler" and possibly easier for the next person working on this code to understand what is happening.
+  (type opensmtpd-table-configuration-type
+        (default #f)
+        (thunked)
+        (sanitize (lambda (var)
+                    (cond [(opensmtpd-table-configuration-data this-record)
+                           (if (list-of-strings? (opensmtpd-table-configuration-data this-record))
+                               (quote list-of-strings)
+                               (quote assoc-list))]
+                          [(file-exists? (opensmtpd-table-configuration-data this-record))
+                           (if (opensmtpd-table-configuration-file-db this-record)
+                               (quote db)
+                               (quote file))]
+                          [else
+                           (display "opensmtpd-table-configuration-type is broke\n")
+                           (throw 'bad! var)])))))
+
+(define-record-type* <opensmtpd-ca-configuration>
+  opensmtpd-ca-configuration make-opensmtpd-ca-configuration
+  opensmtpd-ca-configuration?
+  (name opensmtpd-ca-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca-configuration" "name" (list string?)))))
+  (file opensmtpd-ca-configuration-file
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca-configuration" "file" (list file-exists?))))))
+
+(define-record-type* <opensmtpd-pki-configuration>
+  opensmtpd-pki-configuration make-opensmtpd-pki-configuration
+  opensmtpd-pki-configuration?
+  (domain opensmtpd-pki-configuration-domain
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-pki-configuration" "domain" (list string?)))))
+  ;; TODO/FIXME this should probably be a list of files.  The opensmtpd documentation says
+  ;; that you could have a list of files:
+  ;;
+  ;; pki pkiname cert certfile
+  ;; Associate certificate file certfile with host pkiname, and use that file to prove
+  ;; the identity of the mail server to clients.  pkiname is the server's name, de‐
+  ;; rived from the default hostname or set using either
+  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/mailname or us‐
+  ;; ing the hostname directive.  If a fallback certificate or SNI is wanted, the ‘*’
+  ;; wildcard may be used as pkiname.
+
+  ;; A certificate chain may be created by appending one or many certificates, includ‐
+  ;; ing a Certificate Authority certificate, to certfile.  The creation of certifi‐
+  ;; cates is documented in starttls(8).
+  (cert opensmtpd-pki-configuration-cert
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-pki-configuration" "cert" (list file-exists?)))))
+  (key opensmtpd-pki-configuration-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-pki-configuration" "key" (list file-exists?)))))
+  ; todo sanitize this. valid parameters are "none", "legacy", or "auto".
+  (dhe opensmtpd-pki-configuration-dhe
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-dhe" "dhe" (list false? string?))))))
+
+(define-record-type* <opensmtpd-lmtp-configuration>
+  opensmtpd-lmtp-configuration make-opensmtpd-lmtp-configuration
+  opensmtpd-lmtp-configuration?
+  (destination opensmtpd-lmtp-configuration-destination
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-lmtp-configuration" "destination"
+                                        (list string?)))))
+  (rcpt-to opensmtpd-lmtp-configuration-rcpt-to
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-lmtp-configuration" "rcpt-to"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-mda-configuration>
+  opensmtpd-mda-configuration make-opensmtpd-mda-configuration
+  opensmtpd-mda-configuration?
+  (name opensmtpd-mda-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-mda-configuration" "name"
+                                 (list string?)))))
+  ;; TODO should I allow this command to be a gexp?
+  (command opensmtpd-mda-configuration-command
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-mda-configuration" "command"
+                                    (list string?))))))
+
+(define-record-type* <opensmtpd-maildir-configuration>
+  opensmtpd-maildir-configuration make-opensmtpd-maildir-configuration
+  opensmtpd-maildir-configuration?
+  (pathname opensmtpd-maildir-configuration-pathname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-maildir-configuration" "pathname"
+                                     (list false? string?)))))
+  (junk opensmtpd-maildir-configuration-junk
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-maildir-configuration" "junk"
+                                 (list boolean?))))))
+
+(define-record-type* <opensmtpd-action-local-delivery-configuration>
+  opensmtpd-action-local-delivery-configuration make-opensmtpd-action-local-delivery-configuration
+  opensmtpd-action-local-delivery-configuration?
+  (name opensmtpd-action-local-delivery-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-local-delivery-configuration" "name"
+                                 (list string?)))))
+  (method opensmtpd-action-local-delivery-configuration-method
+          (default "mbox")
+          (sanitize (lambda (var)
+                      (cond
+                       [(or (opensmtpd-lmtp-configuration? var)
+                            (opensmtpd-maildir-configuration? var)
+                            (opensmtpd-mda-configuration? var)
+                            (string=? var "mbox")
+                            (string=? var "expand-only")
+                            (string=? var "forward-only"))
+                        var]
+                       [else
+                        (begin
+                          (display (string-append "<opensmtpd-action-local-delivery-configuration> fieldname 'method' must be of type \n"
+                                                  "\"mbox\", \"expand-only\", \"forward-only\" \n"
+                                                  "<opensmtpd-lmtp-configuration>, <opensmtpd-maildir-configuration>, \n"
+                                                  "or <opensmtpd-mda-configuration>.\n"))
+                          (throw 'bad! var))]))))
+  (alias opensmtpd-action-local-delivery-configuration-alias
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-action-local-delivery-configuration" "alias"
+                                  (list false? opensmtpd-table-configuration?)))))
+  (ttl opensmtpd-action-local-delivery-configuration-ttl
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-local-delivery-configuration" "ttl"
+                                (list false? string?)))))
+  (user opensmtpd-action-local-delivery-configuration-user
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-local-delivery-configuration" "user"
+                                 (list false? string?)))))
+  (userbase opensmtpd-action-local-delivery-configuration-userbase
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-action-local-delivery-configuration" "userbase"
+                                     (list false? opensmtpd-table-configuration?)))))
+  (virtual opensmtpd-action-local-delivery-configuration-virtual
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-action-local-delivery-configuration" "virtual"
+                                    (list false? opensmtpd-table-configuration?)))))
+  (wrapper opensmtpd-action-local-delivery-configuration-wrapper
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-action-local-delivery-configuration" "wrapper"
+                                    (list false? string?))))))
+
+;; FIXME/TODO this is a valid opensmtpd-relay record
+;; (opensmtpd-action-relay-configuration
+;;  (pki (opensmtpd-pki-configuration
+;;        (domain "gnucode.me")
+;;        (cert "opensmtpd.scm")
+;;        (key "opensmtpd.scm"))))
+;; BUT how does it relay the email?  What host does it use?
+;; I think opensmtpd-relay-configuration needs "method" field.
+;; the method field might need to be another record...BUT basically the relay has to have a 'backup', 'backup-mx',
+;; or 'domain', or 'host' defined.
+(define-record-type* <opensmtpd-action-relay-configuration>
+  opensmtpd-action-relay-configuration make-opensmtpd-action-relay-configuration
+  opensmtpd-action-relay-configuration?
+  (name opensmtpd-action-relay-configuration-name
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "name"
+                                 (list string?))))
+        (default #f))
+  (backup opensmtpd-action-relay-configuration-backup ;; boolean
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "backup"
+                                   (list boolean?)))))
+  (backup-mx opensmtpd-action-relay-configuration-backup-mx ;; string mx name
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-action-relay-configuration" "backup-mx"
+                                      (list false? string?)))))
+  (helo opensmtpd-action-relay-configuration-helo
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "helo"
+                                 (list false? string? opensmtpd-table-configuration?))))
+        (default #f))
+  (helo-src opensmtpd-action-relay-configuration-helo-src
+        (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "helo-src"
+                                   (list false? string? opensmtpd-table-configuration?))))
+        (default #f))
+  (domain opensmtpd-action-relay-configuration-domain
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "domain"
+                                   (list false? opensmtpd-table-configuration?))))
+          (default #f))
+  (host opensmtpd-action-relay-configuration-host
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "host"
+                                 (list false? string?))))
+        (default #f))
+  (pki opensmtpd-action-relay-configuration-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "pki"
+                                (list false? opensmtpd-pki-configuration?)))))
+  (srs opensmtpd-action-relay-configuration-srs
+       (default #f)
+       (lambda (var)
+         (my/sanitize var "opensmtpd-action-relay-configuration" "srs"
+                      (list boolean?))))
+  (tls opensmtpd-action-relay-configuration-tls
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "tls"
+                                (list false? string?)))))
+  (auth opensmtpd-action-relay-configuration-auth
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "auth"
+                                 (list false? opensmtpd-table-configuration?))))
+        (default #f))
+  (mail-from opensmtpd-action-relay-configuration-mail-from
+             (default #f))
+  ;; string "127.0.0.1" or "<interface>" or "<table of IP addresses>"
+  ;; TODO should I do some sanitizing to make sure that the string? here is actually an IP address or a valid interface?
+  (src opensmtpd-action-relay-configuration-src
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "src"
+                                (list false? string? opensmtpd-table-configuration?))))
+       (default #f)))
+
+;; this record is used by <opensmtpd-filter-phase-configuration> &
+;; <opensmtpd-match-configuration>
+(define-record-type* <opensmtpd-option-configuration>
+  opensmtpd-option-configuration make-opensmtpd-option-configuration
+  opensmtpd-option-configuration?
+  (option opensmtpd-option-configuration-option
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (and (string? var)
+                               (or (string-in-list? var (list "fcrdns" "rdns"
+                                                          "src" "helo"
+                                                          "auth" "mail-from"
+                                                          "rcpt-to"
+                                                          "for"
+                                                          "for any" "for local"
+                                                          "for domain" "for rcpt-to"
+                                                          "from any" "from auth"
+                                                          "from local" "from mail-from"
+                                                          "from rdns" "from socket"
+                                                          "from src" "auth"
+                                                          "helo" "mail-from"
+                                                          "rcpt-to" "tag" "tls"
+                                                          ))))
+                          var
+                          (begin
+                            (display (string-append "<opensmtpd-option-configuration> fieldname: 'option' is of type \n"
+                                                    "string.  The string can be either 'fcrdns', \n"
+                                                    " 'rdns', 'src', 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
+                                                    "'for', 'for any', 'for local', 'for domain', 'for rcpt-to', \n"
+                                                    "'from any', 'from auth', 'from local', 'from mail-from', 'from rdns', 'from socket', \n"
+                                                    "'from src', 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"
+                                                    ))
+                            (throw 'bad! var))))))
+  (not opensmtpd-option-configuration-not
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-option-configuration" "not"
+                                (list boolean?)))))
+  (regex opensmtpd-option-configuration-regex
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option-configuration" "regex"
+                                  (list boolean?)))))
+  (data opensmtpd-option-configuration-data
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option-configuration" "data"
+                                  (list false? string? opensmtpd-table-configuration?))))))
+
+(define-record-type* <opensmtpd-filter-phase-configuration>
+  opensmtpd-filter-phase-configuration make-opensmtpd-filter-phase-configuration
+  opensmtpd-filter-phase-configuration?
+  (name opensmtpd-filter-phase-configuration-name ;; string chain-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter-phase-configuration" "name"
+                                 (list string?)))))
+  (phase opensmtpd-filter-phase-configuration-phase ;; string
+              (default #f)
+              (sanitize (lambda (var)
+                          ;;(my/sanitize var "opensmtpd-filter-phase-configuration" "phase"
+                          ;;             (list (sanitize-configuration
+                          ;;                    (proc (lambda (value)
+                          ;;                            (and (string? var)
+                          ;;                                 (string-in-list? var (list "connect"
+                          ;;                                                            "helo"
+                          ;;                                                            "mail-from"
+                          ;;                                                            "rcpt-to"
+                          ;;                                                            "data"
+                          ;;                                                            "commit")))))
+                          ;;                    (error-message (list
+                          ;;                                    "<opensmtpd-filter-phase-configuration> fieldname: 'phase' is of type \n"
+                          ;;                                    "string.  The string can be either 'connect',"
+                          ;;                                    " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n ")))))
+                          (if (and (string? var)
+                                   (string-in-list? var (list "connect"
+                                                          "helo"
+                                                          "mail-from"
+                                                          "rcpt-to"
+                                                          "data"
+                                                          "commit")))
+                              var
+                              (begin
+                                (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'phase' is of type \n"
+                                                        "string.  The string can be either 'connect',"
+                                                        " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n "
+                                                        ))
+                                (throw 'bad! var)))
+                          )))
+
+  (options opensmtpd-filter-phase-configuration-options
+              (default #f)
+              (sanitize (lambda (var)
+                          ;; returns #t if list is a unique list of <opensmtpd-option-configuration>
+                          (define (list-of-opensmtpd-option-configuration? list)
+                            (and (list-of-type? list opensmtpd-option-configuration?)
+                                 (not (contains-duplicate? list))))
+
+                          (define (list-has-duplicates-or-non-opensmtpd-option-configuration list)
+                            (not (list-of-opensmtpd-option-configuration? list)))
+
+                          ;; input <opensmtpd-option-configuration>
+                          ;; return #t if <opensmtpd-option-configuration> fieldname 'option'
+                          ;; that needs a corresponding table has one.  Otherwise #f
+                          (define (opensmtpd-option-configuration-has-table? record)
+                            (define decision (opensmtpd-option-configuration-option record))
+                            (and (string? decision)
+                                 ;; if option needs a table, check for a table
+                                 (if (string-in-list? decision (list "src"
+                                                                     "helo"
+                                                                     "mail-from"
+                                                                     "rcpt-to"))
+                                     (opensmtpd-table-configuration? (opensmtpd-option-configuration-data record))
+                                     #t)))
+
+                          (define (list-of-opensmtpd-option-configuration-has-table? list)
+                            (list-of-type? list opensmtpd-option-configuration-has-table?))
+
+                          (define (some-opensmtpd-option-configuration-in-list-lack-table? list)
+                            (not (list-of-opensmtpd-option-configuration-has-table? list)))
+
+                          ;;each element in list is of type <opensmtpd-option-configuration>
+                          (cond [(list-has-duplicates-or-non-opensmtpd-option-configuration var)
+                                 (begin
+                                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'options' is a list of unique \n"
+                                                           "<opensmtpd-option-configuration> records.\n"))
+                                   (throw 'bad! var))]
+                                ;; if fieldname 'option' is of string 'src', 'helo', 'mail-from', 'rcpt-to', then there should be a table
+                                [(some-opensmtpd-option-configuration-in-list-lack-table? var)
+                                 (begin
+                                   (display (string-append "<opensmtpd-option-configuration>'s fieldname 'option' values of \n"
+                                                           "'src', 'helo', 'mail-from', or 'rcpt-to' need a corresponding 'table' \n"
+                                                           " of type <opensmtpd-table-configuration>. eg: \n"
+                                                           "(opensmtpd-option-configuration \n"
+                                                           "   (option \"src\")\n"
+                                                           "   (table (opensmtpd-table-configuration \n"
+                                                           "              (name \"src-table\")\n"
+                                                           "              (data (list \"hello\" \"cat\")))))\n"))
+                                   ;; TODO it would be nice if the var this error message throws in the bad
+                                   ;; <opensmtpd-option-configuration>, instead of the list of records.
+                                   (throw 'bad! var))]
+                                [else var]))))
+  (decision opensmtpd-filter-phase-configuration-decision
+            (default #f)
+            (sanitize (lambda (var)
+                        (if (and (string? var)
+                                 (string-in-list? var (list "bypass" "disconnect"
+                                                            "reject" "rewrite" "junk")))
+                            var
+                            (begin
+                              (display (string-append "<opensmtpd-filter-decision> fieldname: 'decision' is of type \n"
+                                                      "string.  The string can be either 'bypass',"
+                                                      " 'disconnect', 'reject', 'rewrite', or 'junk'.\n"))
+                              (throw 'bad! var))))))
+  (message opensmtpd-filter-phase-configuration-message
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase-configuration" "message"
+                                    (list false? string?)))))
+  (value opensmtpd-filter-phase-configuration-value
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase-configuration" "value"
+                                    (list false? number?))))))
+
+(define-record-type* <opensmtpd-filter-configuration>
+  opensmtpd-filter-configuration make-opensmtpd-filter-configuration
+  opensmtpd-filter-configuration?
+  (name opensmtpd-filter-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "name"
+                                 (list string?)))))
+  (exec opensmtpd-filter-exec
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "exec"
+                                 (list boolean?)))))
+  (proc opensmtpd-filter-configuration-proc ; a string like "rspamd" or the command to start it like "/path/to/rspamd --option=arg --2nd-option=arg2"
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-filter" "proc"
+                                      (list string?))))))
+
+;; There is another type of filter that opensmtpd supports, which is a filter chain.
+;; A filter chain is a list of <opensmtpd-filter-phase-configuration> and <opensmtpd-filter-configuration>.
+;; This lets you apply several filters under one filter name.  I could have defined
+;; a record type for it, but the record would only have had two fields: name and list-of-filters.
+;; Why write that as a record?  That's too simple.
+;; returns #t if list is a unique list of <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>
+;; returns # otherwise
+(define (opensmtpd-filter-chain? %filters)
+  (and (list-of-unique-filter-or-filter-phase? %filters)
+       (< 1 (length %filters))))
+
+(define-record-type* <opensmtpd-listen-on-configuration>
+  opensmtpd-listen-on-configuration make-opensmtpd-listen-on-configuration
+  opensmtpd-listen-on-configuration?
+  ;; interface may be an IP address, interface group, or domain name
+  (interface opensmtpd-listen-on-configuration-interface
+             (default "lo"))
+  (family opensmtpd-listen-on-configuration-family
+          (default #f)
+          (sanitize (lambda (var)
+                      (cond
+                       [(eq? #f var) ;; var == #f
+                        var]
+                       [(and (string? var)
+                             (string-in-list? var (list "inet4" "inet6")))
+                        var]
+                       [else
+                        (begin
+                          (display "<opensmtpd-listen-on-configuration> fieldname 'family' must be string \"inet4\" or \"inet6\".\n")
+                          (throw 'bad! var))]))))
+  (auth opensmtpd-listen-on-configuration-auth
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-listen-on-configuration" "auth"
+                                 (list boolean? table-whose-data-are-assoc-list?)))))
+  (auth-optional opensmtpd-listen-on-configuration-auth-optional
+                 (default #f)
+                 (sanitize (lambda (var)
+                             (my/sanitize var "opensmtpd-listen-on-configuration" "auth-optional"
+                                          (list boolean?
+                                                table-whose-data-are-assoc-list?)))))
+  ;; TODO add a ca entry?
+  ;; string FIXME/TODO sanitize this to support a gexp.  That way way the
+  ;; includes directive can include my hacky scheme code that I use for opensmtpd-dkimsign.
+  (filters opensmtpd-listen-on-configuration-filters
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-filters var))))
+  (hostname opensmtpd-listen-on-configuration-hostname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-listen-on-configuration" "hostname"
+                                     (list false? string?)))))
+  (hostnames opensmtpd-listen-on-configuration-hostnames
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-listen-on-configuration" "hostnames"
+                                      (list false? table-whose-data-are-assoc-list?)))))
+  (mask-src opensmtpd-listen-on-configuration-mask-src
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-listen-on-configuration" "mask-src"
+                                     (list boolean?)))))
+  (disable-dsn opensmtpd-listen-on-configuration-disable-dsn
+          (default #f))
+  (pki opensmtpd-listen-on-configuration-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "pki"
+                                (list false? opensmtpd-pki-configuration?)))))
+  (port opensmtpd-listen-on-configuration-port
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-listen-on-configuration" "port"
+                                 (list false? integer?)))))
+  (proxy-v2 opensmtpd-listen-on-configuration-proxy-k2
+            (default #f))
+  (received-auth opensmtpd-listen-on-configuration-received-auth
+                 (default #f))
+  ;; TODO add in a senders option!
+  ;; string or <opensmtpd-senders> record
+  ;; (senders opensmtpd-listen-on-configuration-senders
+  ;;          (sanitize (lambda (var)
+  ;;                      (my/sanitize var "opensmtpd-listen-on-configuration" "port" (list false? integer?))))
+  ;;          (default #f))
+  (secure-connection opensmtpd-listen-on-configuration-secure-connection
+                     (default #f)
+                     (sanitize (lambda (var)
+                                 (cond [(boolean? var)
+                                        var]
+                                       [(and (string? var)
+                                             (string-in-list? var
+                                                              (list "smtps" "tls"
+                                                                    "tls-require"
+                                                                    "tls-require-verify")))
+                                        var]
+                                       [else
+                                        (begin
+                                          (display (string-append "<opensmtd-listen-on> fieldname 'secure-connection' can be \n"
+                                                                  "one of the following strings: \n'smtps', 'tls', 'tls-require', \n"
+                                                                  "or 'tls-require-verify'.\n"))
+                                          (throw 'bad! var))]))))
+  (tag opensmtpd-listen-on-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+(define-record-type* <opensmtpd-listen-on-socket-configuration-configuration>
+  opensmtpd-listen-on-socket-configuration-configuration make-opensmtpd-listen-on-socket-configuration-configuration
+  opensmtpd-listen-on-socket-configuration-configuration?
+  ;; false or <opensmtpd-filter-configuration> or list of <opensmtpd-filter-configuration>
+  (filters opensmtpd-listen-on-socket-configuration-configuration-filters
+           (sanitize (lambda (var)
+                       (sanitize-filters var)))
+          (default #f))
+  (mask-src opensmtpd-listen-on-socket-configuration-configuration-mask-src
+            (default #f))
+  (tag opensmtpd-listen-on-socket-configuration-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+
+(define-record-type* <opensmtpd-match-configuration>
+  opensmtpd-match-configuration make-opensmtpd-match-configuration
+  opensmtpd-match-configuration?
+  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
+  ;;is #t, then the match record will be a reject match record.
+  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action 'reject))
+  ;; To do this, I will also have to  'reject' mutually exclusive. AND an match with 'reject' can have no action defined.
+  (action opensmtpd-match-configuration-action
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (or (opensmtpd-action-relay-configuration? var)
+                              (opensmtpd-action-local-delivery-configuration? var)
+                              (eq? (quote reject) var))
+                          var
+                          (begin
+                            (display
+                             (string-append "<opensmtpd-match-configuration> fieldname 'action' is of type <opensmtpd-action-relay-configuration>, \n"
+                                            "<opensmtpd-action-local-delivery-configuration>, or (quote reject).\n"
+                                            "If its var is (quote reject), then the match rejects the incoming message\n"
+                                            "during the SMTP dialogue.\n"))
+                            (throw 'bad! var))))))
+  (options opensmtpd-match-configuration-options
+           (default #f)
+           (sanitize (lambda (var)
+                       (cond ((not var)
+                              #f)
+                             ((not (list-of-unique-opensmtpd-option-configuration? var))
+                              (throw-error var '("<opensmtpd-match-configuration> fieldname 'options' is a list of unique \n"
+                                                 "<opensmtpd-option-configuration> records. \n")))
+                           (else (sanitize-list-of-options-for-match-configuration var)))))))
+
+(define-record-type* <opensmtpd-smtp-configuration>
+  opensmtpd-smtp-configuration make-opensmtpd-smtp-configuration
+  opensmtpd-smtp-configuration?
+  (ciphers opensmtpd-smtp-configuration-ciphers
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-smtp-configuration" "ciphers"
+                                    (list false? string?)))))
+  (limit-max-mails opensmtpd-smtp-configuration-limit-max-mails
+                   (default #f)
+                   (sanitize (lambda (var)
+                               (my/sanitize var "opensmtpd-smtp-configuration" "limit-max-mails"
+                                            (list false? integer?)))))
+  (limit-max-rcpt opensmtpd-smtp-configuration-limit-max-rcpt
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp-configuration" "limit-max-rcpt"
+                                           (list false? integer?)))))
+  (max-message-size opensmtpd-smtp-configuration-max-message-size
+                    (default #f)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-smtp-configuration" "max-message-size"
+                                             (list false? integer? string?)))))
+  ;; FIXME/TODO the sanitize function of sub-addr-delim should accept a string of length one not string?
+  (sub-addr-delim opensmtpd-smtp-configuration-sub-addr-delim
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp-configuration" "sub-addr-delim"
+                                           (list false? integer? string?))))))
+
+(define-record-type* <opensmtpd-srs-configuration>
+  opensmtpd-srs-configuration make-opensmtpd-srs-configuration
+  opensmtpd-srs-configuration?
+  ;; TODO should this be a file?
+  (key opensmtpd-srs-configuration-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-srs-configuration" "key"
+                                (list false? boolean? string?)))))
+  ;; TODO should this also be a file?
+  (backup-key opensmtpd-srs-configuration-backup-key
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-srs-configuration" "backup-key"
+                                       (list false? integer?)))))
+  (ttl-delay opensmtpd-srs-configuration-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-srs-configuration" "ttl-delay"
+                                      (list false? string?))))))
+
+(define-record-type* <opensmtpd-queue-configuration>
+  opensmtpd-queue-configuration make-opensmtpd-queue-configuration
+  opensmtpd-queue-configuration?
+  (compression opensmtpd-queue-configuration-compression
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-queue-configuration" "compression"
+                                        (list boolean?)))))
+  (encryption opensmtpd-queue-configuration-encryption
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-queue-configuration" "encryption"
+                                       (list boolean? file-exists? string?)))))
+  (ttl-delay opensmtpd-queue-configuration-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-queue-configuration" "ttl-delay"
+                                      (list false? string?))))))
+
 (define-record-type* <opensmtpd-configuration>
   opensmtpd-configuration make-opensmtpd-configuration
   opensmtpd-configuration?
-  (package     opensmtpd-configuration-package
-               (default opensmtpd))
+  (package opensmtpd-configuration-package
+           (default opensmtpd))
   (config-file opensmtpd-configuration-config-file
-               (default %default-opensmtpd-config-file)))
+               (default #f))
+  ;; FIXME/TODO should I include a admd authservid entry?
+
+  ;; TODO sanitize this properly with perhaps a <sanitize-configuration>.
+  (bounce opensmtpd-configuration-bounce
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-configuration" "bounce"
+                                   (list false? list?)))))
+  (cas opensmtpd-configuration-cas
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "cas"
+                                (list false? list-of-opensmtpd-ca-configuration?)))))
+  ;; list of many records of type opensmtpd-listen-on-configuration
+  (listen-ons opensmtpd-configuration-listen-ons
+              (default (list (opensmtpd-listen-on-configuration)))
+              (sanitize (lambda (var)
+                          (if (list-of-opensmtpd-listen-on-configuration? var)
+                              var
+                              (begin
+                                (display "<opensmtpd-configuration> fieldname 'listen-ons' expects a list of records ")
+                                (display "of one or more unique <opensmtpd-listen-on-configuration> records.\n")
+                                (throw 'bad! var))))))
+  ;; accepts type <opensmtpd-listen-on-socket-configuration-configuration>
+  (listen-on-socket opensmtpd-configuration-listen-on-socket
+                    (default (opensmtpd-listen-on-socket-configuration-configuration)))
+  (includes opensmtpd-configuration-includes ;; list of strings of absolute path names
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-configuration" "includes"
+                                     (list false? list-of-strings?)))))
+  (matches opensmtpd-configuration-matches
+           (default (list (opensmtpd-match-configuration
+                           (action (opensmtpd-action-local-delivery-configuration
+                                    (name "local")
+                                    (method "mbox")))
+                           (options (list
+                                     (opensmtpd-option-configuration
+                                      (option "for local")))))
+                          (opensmtpd-match-configuration
+                           (action (opensmtpd-action-relay-configuration
+                                    (name "outbound")))
+                           (options (list
+                                     (opensmtpd-option-configuration
+                                      (option "from local"))
+                                     (opensmtpd-option-configuration
+                                      (option "for any")))))))
+           ;; TODO perhaps I should sanitize this function like I sanitized the 'filters'.
+           ;; I definitely should sanitize this function a bit more.  For example, you could have two different
+           ;; actions, one for local delivery and one for remote, with the same name.  I should make sure that
+           ;; I have no two different actions with the same name.
+           (sanitize (lambda (var)
+                       ;; Should we do more sanitizing here?  eg: "from socket" should NOT have a table or value
+                       var
+                       (my/sanitize var "opensmtpd-configuration" "matches"
+                                    (list list-of-unique-opensmtpd-match-configuration?)))))
+  ;; list of many records of type mda-wrapper
+  ;; TODO/FIXME support using gexps here
+  ;; eg (list "name" gexp)
+  (mda-wrappers opensmtpd-configuration-mda-wrappers
+                (default #f)
+                (sanitize (lambda (var)
+                            (my/sanitize var
+                                         "opensmtpd-configuration"
+                                         "mda-wrappers"
+                                         (list false? string?)))))
+  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
+                    (default 100)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-configuration" "mta-max-deferred"
+                                             (list number?)))))
+
+  ;; TODO should I add a fieldname proc _proc-name_ _command_ as found in the man 5 smtpd.conf ?
+
+  (queue opensmtpd-configuration-queue
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-configuration" "queue"
+                                  (list false? opensmtpd-queue-configuration?)))))
+  (smtp opensmtpd-configuration-smtp
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-configuration" "smtp"
+                                 (list false? opensmtpd-smtp-configuration?)))))
+  (srs opensmtpd-configuration-srs
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "srs"
+                                (list false? opensmtpd-srs-configuration?))))))
+
+;; This is a non-exported record for passing around sanitize procedures.
+;; As of 5/2/2022 I am not using it.  I should probably just delete it.
+(define-record-type* <sanitize-configuration>
+  sanitize-configuration make-sanitize-configuration
+  sanitize-configuration?
+  (proc sanitize-configuration-proc
+          (default #f)
+          ;;(sanitize (lambda (var) (procedure? var)))
+          )
+  (args sanitize-configuration-args
+       (default #f)
+       ;;(sanitize (lambda (var) (lambda (var) (list? var))))
+       )
+  (error-message sanitize-configuration-error-message
+         (default #f)
+         ;;(sanitize (lambda (var) (list? var)))
+         )
+  (error-if-proc-fails sanitize-configuration-error-if-proc-fails
+                       (default #f)))
+
+;; this help procedure is used 3 or 4 times by sanitize-list-of-options-for-match-configuration
+(define (throw-error-duplicate-option option error-arg)
+  (throw-error error-arg
+               (list "<opensmtpd-match-configuration>'s fieldname 'options' has two\n"
+                     (string-append "<opensmtpd-option-configuration> records with fieldname 'option' with value '" option "'. \n")
+                     (string-append "You can only have one option with value '" option "' in the options list.\n"))))
+
+;; this procedure sanitizes the fieldname opensmtpd-match-configuration-options
+(define* (sanitize-list-of-options-for-match-configuration %options)
+  (let loop ([%traversing-options %options]
+             [%sanitized-options '()])
+    (if (null? %traversing-options)
+           (remove false?
+                   (list
+                    (assoc-ref %sanitized-options "for")
+                    (assoc-ref %sanitized-options "from")
+                    (assoc-ref %sanitized-options "auth")
+                    (assoc-ref %sanitized-options "helo")
+                    (assoc-ref %sanitized-options "mail-from")
+                    (assoc-ref %sanitized-options "rcpt-to")
+                    (assoc-ref %sanitized-options "tag")
+                    (assoc-ref %sanitized-options "tls")))
+          (let* ((option-record (car %traversing-options))
+                 (option-string (opensmtpd-option-configuration-option option-record)))
+            (cond [(string=? "auth" option-string)
+                   (if (assoc-ref %sanitized-options "auth")
+                       (throw-error-duplicate-option "auth" %traversing-options)
+                       (loop (cdr %traversing-options) (alist-cons "auth" option-record %sanitized-options)))]
+                  [(string=? "helo" option-string)
+                   (cond [(assoc-ref %sanitized-options "helo")
+                          (throw-error-duplicate-option "helo" %traversing-options)]
+                         [(not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'helo' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "helo" option-record %sanitized-options))])]
+                  [(string=? "mail-from" option-string)
+                   (cond ((assoc-ref %sanitized-options "mail-from")
+                          (throw-error-duplicate-option "mail-from" %traversing-options))
+                         ((not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'mail-from' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "mail-from" option-record %sanitized-options))))]
+                  [(string=? "rcpt-to" option-string)
+                   (cond [(assoc-ref %sanitized-options "rcpt-to")
+                          (throw-error-duplicate-option "rcpt-to" %traversing-options)]
+                         [(not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'rcpt-to' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "rcpt-to" option-record %sanitized-options))])]
+                  [(string=? "tag" option-string)
+                   (cond ((assoc-ref %sanitized-options "tag")
+                          (throw-error-duplicate-option "tag" %traversing-options))
+                         ((not (string? (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'tag' \n"
+                                             "must have a 'data' of type string.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "tag" option-record %sanitized-options))))]
+                  [(string=? "tls" option-string)
+                   (cond [(assoc-ref %sanitized-options "tls")
+                          (throw-error-duplicate-option "tls" %traversing-options)]
+                         [(or (opensmtpd-option-configuration-data option-record)
+                              (opensmtpd-option-configuration-regex option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'tls' \n"
+                                             "cannot have a string or table 'data'.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "tls" option-record %sanitized-options))])]
+                  [(string=? "for" (substring option-string 0 3))
+                   (cond ((assoc-ref %sanitized-options "for")
+                          (throw-error %options
+                                       `("<opensmtpd-match-configuration>'s fieldname 'options' can only have one 'for' option. \n"
+                                         "But '" ,option-string "' and '"
+                                         ,(opensmtpd-option-configuration-option (assoc-ref %sanitized-options "for")) "' are present.\n")))
+                         ((and (string-in-list? option-string (list "for any" "for local")) ; for any cannot have a data field.
+                               (or (opensmtpd-option-configuration-data option-record)
+                                   (opensmtpd-option-configuration-regex option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for any' \n"
+                                             "or 'for local', then its 'data' and 'regex' field must be #f. \n")))
+                         ((and (string-in-list? option-string (list "for domain" "for rcpt-to")) ; for domain must have a data field.
+                               (not (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for domain' \n"
+                                             "or 'for rcpt-to', then its 'data' field must be a string or an \n"
+                                             "<opensmtpd-table-configuration> record.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "for" option-record %sanitized-options))))]
+                  [(string=? "from" (substring option-string 0 4))
+                   (cond ((assoc-ref %sanitized-options "from")
+                          (throw-error %options
+                                       `("<opensmtpd-match-configuration>'s fieldname 'options' can only have one 'from' option. \n"
+                                         "But '" ,option-string "' and '"
+                                         ,(opensmtpd-option-configuration-option (assoc-ref %sanitized-options "from")) "' are present.\n")))
+                         ((and (string-in-list? option-string (list "from any" "from local" "from socket")) ; for any cannot have a data field.
+                               (or (opensmtpd-option-configuration-data option-record)
+                                   (opensmtpd-option-configuration-regex option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from any', \n"
+                                             " 'from local', or 'from socket', then its 'data' and 'regex' field must be #f. \n")))
+                         ((and (string-in-list? option-string (list "from mail-from" "from src")) ; for domain must have a data field.
+                               (not (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from mail-from' \n"
+                                             "or 'from src', then its 'data' field must be a string or an \n"
+                                             "<opensmtpd-table-configuration> record.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "from" option-record %sanitized-options))))])))))
+
+;; some procedures for <opensmtpd-listen-on-configuration> and
+;; <opensmtpd-listen-on-socket-configuration-configuration>.
+(define (sanitize-filters %list)
+  ;; the order of the first two tests in this cond is important.
+  ;; (false?) has to be 1st and (list-has-duplicates-or-non-filters?) has to be second.
+  ;; You may optionally re-order the other alternates in the cond.
+  (cond [(false? %list)
+         #f]
+        [(list-has-duplicates-or-non-filters? %list)
+         (begin
+           (display (string-append "<opensmtpd-listen-on-configuration> fieldname: 'filters' is a list, in which each unique element \n"
+                                   "is of type <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>.\n"))
+           (throw 'bad! %list))]
+        [else
+         (let loop ([%traversing-list %list]
+                    [%original-list %list])
+           (if (null? %traversing-list)
+               %original-list
+               (cond
+                [(opensmtpd-filter-configuration? (car %traversing-list))
+                 (loop (cdr %traversing-list) %original-list)]
+                [(filter-phase-has-message-and-value? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> cannot have defined fieldnames 'value' \n"
+                                           "and 'message'.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-decision-lacks-proper-message? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'decision' options \n"
+                                           "\"disconnect\" and \"reject\" require fieldname 'message' to have a string.\n"
+                                           "The 'message' string must be RFC commpliant, which means that the string \n"
+                                           "must begin with a 4xx or 5xx status code.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-lacks-proper-value? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'decision' option \n"
+                                           "\"rewrite\" requires fieldname 'value' to have a number.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-has-incorrect-junk-or-bypass? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname 'decision' option \n"
+                                           "\"junk\" or 'bypass' cannot have a defined fieldnames 'message' or 'value'.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-junks-after-commit? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname 'decision' option \n"
+                                           "\"junk\" cannot junk an email during 'phase' \"commit\".\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [else (loop (cdr %traversing-list) %original-list)])))]))
+
+(define (list-has-duplicates-or-non-filters? list)
+  (not (list-of-unique-filter-or-filter-phase? list)))
+
+(define (filter-phase-has-message-and-value? record)
+  (and (opensmtpd-filter-phase-configuration-message record)
+       (opensmtpd-filter-phase-configuration-value record)))
+
+;; return #t if phase needs a message. Or if the message did not start with a 4xx or 5xx status code.
+;; otherwise #f
+(define (filter-phase-decision-lacks-proper-message? record)
+  (define decision (opensmtpd-filter-phase-configuration-decision record))
+  (if (string-in-list? decision (list "disconnect" "reject"))
+      ;; this message needs to be RFC compliant, meaning
+      ;; that it need to start with 4xx or 5xx status code
+      (cond [(eq? #f (opensmtpd-filter-phase-configuration-message record))
+             #t]
+            [(string? (opensmtpd-filter-phase-configuration-message record))
+             (let ((number (string->number
+                            (substring
+                             (opensmtpd-filter-phase-configuration-message record) 0 3))))
+               (if (and (number? number)
+                        (and (< number 600) (> number 399)))
+                   #f
+                   #t))])
+      #f))
+
+;; 'decision' "rewrite" requires 'value' to be a number.
+(define (filter-phase-lacks-proper-value? record)
+  (define decision (opensmtpd-filter-phase-configuration-decision record))
+  (if (string=? "rewrite" decision)
+      (if (and (number? (opensmtpd-filter-phase-configuration-value record))
+               (eq? #f (opensmtpd-filter-phase-configuration-message record)))
+          #f
+          #t)
+      #f))
+
+;; 'decision' "junk" or "bypass" cannot have a message or a value.
+(define (filter-phase-has-incorrect-junk-or-bypass? record)
+  (and
+   (string-in-list?
+    (opensmtpd-filter-phase-configuration-decision record)
+    (list "junk" "bypass"))
+   (or
+    (opensmtpd-filter-phase-configuration-value record)
+    (opensmtpd-filter-phase-configuration-message record))))
+
+(define (filter-phase-junks-after-commit? record)
+  (and (string=? (opensmtpd-filter-phase-configuration-decision record) "junk")
+       (string=? (opensmtpd-filter-phase-configuration-phase record) "commit")))
+
+;; returns #t if list is a unique list of <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>
+;; returns # otherwise
+(define (list-of-unique-filter-or-filter-phase? %filters)
+  (and (list? %filters)
+       (not (null? %filters))
+       ;; this list is made up of only <opensmtpd-filter-phase-configuration> or <opensmtpd-filter-configuration>
+       (primitive-eval
+        (cons 'and (map (lambda (filter)
+                          (or (opensmtpd-filter-configuration? filter)
+                              (opensmtpd-filter-phase-configuration? filter)))
+                        %filters)))
+       (not (contains-duplicate? %filters))))
+
+(define (throw-error var %strings)
+  (display (apply string-append %strings))
+  (throw 'bad! var))
+
+;; this is used for sanitizing <opensmtpd-filter-phase-configuration> fieldname 'options'
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+      ;; check if (car list) is in (cdr list)
+       (primitive-eval (cons 'or
+                                (map (lambda (var) (equal? var (car list)))
+                                     (cdr list))))
+       ;; check if (cdr list) contains duplicate
+       (contains-duplicate? (cdr list)))))
+
+;; given a list and procedure, this tests that each element of list is of type
+;; ie: (list-of-type? list string?) tests each list is of type string.
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ([list list])
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+
+(define (list-of-strings? list)
+  (list-of-type? list string?))
+
+(define (list-of-unique-opensmtpd-option-configuration? list)
+  (and (list-of-type?
+        list opensmtpd-option-configuration?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-opensmtpd-ca-configuration? list)
+  (list-of-type? list opensmtpd-ca-configuration?))
+
+(define (list-of-opensmtpd-pki-configuration? list)
+  (list-of-type? list opensmtpd-pki-configuration?))
+
+(define (list-of-opensmtpd-listen-on-configuration? list)
+  (and (list-of-type? list opensmtpd-listen-on-configuration?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-unique-opensmtpd-match-configuration? list)
+  (and (list-of-type? list opensmtpd-match-configuration?)
+       (not (contains-duplicate? list))))
+
+(define* (list-of-strings->string list
+                                  #:key
+                                  (string-delimiter ", ")
+                                  (postpend "")
+                                  (append "")
+                                  (drop-right-number 2))
+  (string-drop-right
+   (string-append (let loop ([list list])
+                    (if (null? list)
+                        ""
+                        (string-append append (car list) postpend
+                                       string-delimiter
+                                       (loop (cdr list)))))
+                  append)
+   drop-right-number))
+
+;; at the moment I cannot define this by using list-of-type?
+;; the first (not (null? assoc-list)) prevents that.
+(define (assoc-list? assoc-list)
+  (list-of-type? assoc-list (lambda (pair)
+                              (if (and (pair? pair)
+                                       (string? (car pair))
+                                       (string? (cdr pair)))
+                                  #t
+                                  #f))))
+
+(define* (variable->string var #:key (append "") (postpend " "))
+  (let ([var (if (number? var)
+                 (number->string var)
+                 var)])
+    (if var
+        (string-append append var postpend)
+        "")))
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is an assoc-list, then it returns
+;; #t, #f if otherwise.
+;; TODO should I remove these two functions?  And instead use the (opensmtpd-table-configuration-type) procedure?
+(define (table-whose-data-are-assoc-list? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (assoc-list? (opensmtpd-table-configuration-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is a list of strings, then it returns
+;; #t, #f if otherwise.
+(define (table-whose-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (list-of-strings? (opensmtpd-table-configuration-data table))))
+
+;; these next few functions help me to turn <table>s
+;; into strings suitable to fit into "opensmtpd.conf".
+(define (assoc-list->string assoc-list)
+  (string-drop-right
+   (let loop ([assoc-list assoc-list])
+     (if (null? assoc-list)
+         ""
+         ;; pair is (cons "hello" "world") -> ("hello" . "world")
+         (let ([pair (car assoc-list)])
+           (string-append
+            "\"" (car pair)  "\""
+            " = "
+            "\"" (cdr pair) "\""
+            ", "
+            (loop (cdr assoc-list))))))
+   2))
+
+;; can be of type: (quote list-of-strings) or (quote assoc-list)
+(define (opensmtpd-table-configuration->string table)
+  (string-append "table " (opensmtpd-table-configuration-name table) " "
+                 (let ([type (opensmtpd-table-configuration-type table)])
+                   (cond [(eq? type (quote list-of-strings))
+                          (string-append "{ " (list-of-strings->string (opensmtpd-table-configuration-data table)
+                                                                       #:append "\""
+                                                                       #:drop-right-number 3
+                                                                       #:postpend "\"") " }")]
+                         [(eq? type (quote assoc-list))
+                          (string-append "{ " (assoc-list->string (opensmtpd-table-configuration-data table)) " }")]
+                         [(eq? type (quote db))
+                          (string-append "db:" (opensmtpd-table-configuration-data table))]
+                         [(eq? type (quote file))
+                          (string-append "file:" (opensmtpd-table-configuration-data table))]
+                         [else (throw 'youMessedUp table)]))
+                 " \n"))
+
+;;  The following functions convert various records into strings.
+
+(define (opensmtpd-listen-on-configuration->string record)
+  (string-append "listen on "
+                 (opensmtpd-listen-on-configuration-interface record) " "
+                 (let* ([hostname (opensmtpd-listen-on-configuration-hostname record)]
+                        [hostnames (if (opensmtpd-listen-on-configuration-hostnames record)
+                                       (opensmtpd-table-configuration-name (opensmtpd-listen-on-configuration-hostnames record))
+                                       #f)]
+                        [filters (opensmtpd-listen-on-configuration-filters record)]
+                        [filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter-configuration? (car filters))
+                                                 (opensmtpd-filter-configuration-name (car filters))
+                                                 (opensmtpd-filter-phase-configuration-name (car filters))))
+                                         #f)]
+                        [mask-src (opensmtpd-listen-on-configuration-mask-src record)]
+                        [tag (opensmtpd-listen-on-configuration-tag record)]
+                        [secure-connection (opensmtpd-listen-on-configuration-secure-connection record)]
+                        [port (opensmtpd-listen-on-configuration-port record)]
+                        [pki (opensmtpd-listen-on-configuration-pki record)]
+                        [auth (opensmtpd-listen-on-configuration-auth record)]
+                        [auth-optional (opensmtpd-listen-on-configuration-auth-optional record)])
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string hostname #:append "hostname ")
+                    (variable->string hostnames #:append "hostnames <" #:postpend "> ")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    (if secure-connection
+                        (cond [(string=? "smtps" secure-connection)
+                               "smtps "]
+                              [(string=? "tls" secure-connection)
+                               "tls "]
+                              [(string=? "tls-require" secure-connection)
+                               "tls-require "]
+                              [(string=? "tls-require-verify" secure-connection)
+                               "tls-require verify "])
+                        "")
+                    (variable->string port #:append "port " #:postpend " ")
+                    (if pki
+                        (variable->string (opensmtpd-pki-configuration-domain pki) #:append "pki ")
+                        "")
+                    (if auth
+                        (string-append "auth "
+                                       (if (opensmtpd-table-configuration? auth)
+                                           (string-append "<" (opensmtpd-table-configuration-name auth) "> ")
+                                           ""))
+                        "")
+                    (if auth-optional
+                        (string-append "auth-optional "
+                                       (if (opensmtpd-table-configuration? auth-optional)
+                                           (string-append "<" (opensmtpd-table-configuration-name auth-optional) "> ")
+                                           ""))
+                        "")
+                    "\n"))))
+
+(define (opensmtpd-listen-on-socket-configuration->string record)
+  (string-append "listen on socket "
+                 (let* ([filters (opensmtpd-listen-on-socket-configuration-configuration-filters record)]
+                        [filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter-configuration? (car filters))
+                                                 (opensmtpd-filter-configuration-name (car filters))
+                                                 (opensmtpd-filter-phase-configuration-name (car filters))))
+                                         #f)]
+                        [mask-src (opensmtpd-listen-on-socket-configuration-configuration-mask-src record)]
+                        [tag (opensmtpd-listen-on-socket-configuration-configuration-tag record)])
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    "\n"))))
+
+(define (opensmtpd-action-relay-configuration->string record)
+  (let ([backup (opensmtpd-action-relay-configuration-backup record)]
+        [backup-mx (opensmtpd-action-relay-configuration-backup-mx record)]
+        [helo (opensmtpd-action-relay-configuration-helo record)]
+        ;; helo-src can either be a string IP address or an <opensmtpd-table-configuration>
+        [helo-src (if (opensmtpd-action-relay-configuration-helo-src record)
+                      (if (string? (opensmtpd-action-relay-configuration-helo-src record))
+                          (opensmtpd-action-relay-configuration-helo-src record)
+                          (string-append "<\""
+                                         (opensmtpd-table-configuration-name
+                                          (opensmtpd-action-relay-configuration-src record))
+                                         "\">"))
+                      #f)]
+        [domain (if (opensmtpd-action-relay-configuration-domain record)
+                    (opensmtpd-table-configuration-name
+                     (opensmtpd-action-relay-configuration-domain record))
+                    #f)]
+        [host (opensmtpd-action-relay-configuration-host record)]
+        [name (opensmtpd-action-relay-configuration-name record)]
+        [pki (if (opensmtpd-action-relay-configuration-pki record)
+                 (opensmtpd-pki-configuration-domain (opensmtpd-action-relay-configuration-pki record))
+                 #f)]
+        [srs (opensmtpd-action-relay-configuration-srs record)]
+        [tls (opensmtpd-action-relay-configuration-tls record)]
+        [auth (if (opensmtpd-action-relay-configuration-auth record)
+                  (opensmtpd-table-configuration-name
+                   (opensmtpd-action-relay-configuration-auth record))
+                  #f)]
+        [mail-from (opensmtpd-action-relay-configuration-mail-from record)]
+        ;; src can either be a string IP address or an <opensmtpd-table-configuration>
+        [src (if (opensmtpd-action-relay-configuration-src record)
+                 (if (string? (opensmtpd-action-relay-configuration-src record))
+                     (opensmtpd-action-relay-configuration-src record)
+                     (string-append "<\""
+                                    (opensmtpd-table-configuration-name
+                                     (opensmtpd-action-relay-configuration-src record))
+                                    "\">"))
+                 #f)]
+        )
+    (string-append
+     "\""
+     name
+     "\" " "relay "
+     ;;FIXME should I always quote the host fieldname? do I need to quote localhost via "localhost" ?
+     (variable->string host #:append "host \"" #:postpend "\" ")
+     (variable->string backup)
+     (variable->string backup-mx #:append "backup mx ")
+     (variable->string helo #:append "helo ")
+     (variable->string helo-src #:append "helo-src ")
+     (variable->string domain #:append "domain <\"" #:postpend "\"> ")
+     (variable->string host #:append "host ")
+     (variable->string pki #:append "pki ")
+     (variable->string srs)
+     (variable->string tls #:append "tls ")
+     (variable->string auth #:append "auth <" #:postpend "> ")
+     (variable->string mail-from #:append "mail-from ")
+     (variable->string src #:append "src ")
+     "\n")))
+
+(define (opensmtpd-lmtp-configuration->string record)
+  (string-append "lmtp "
+                 (opensmtpd-lmtp-configuration-destination record)
+                 (if (opensmtpd-lmtp-configuration-rcpt-to record)
+                     (begin
+                       " " (opensmtpd-lmtp-configuration-rcpt-to record))
+                     "")))
+
+(define (opensmtpd-mda-configuration->string record)
+  (string-append "mda "
+                 (opensmtpd-mda-configuration-command record) " "))
+
+(define (opensmtpd-maildir-configuration->string record)
+  (string-append "maildir "
+                 "\""
+                 (if (opensmtpd-maildir-configuration-pathname record)
+                     (opensmtpd-maildir-configuration-pathname record)
+                     "~/Maildir")
+                 "\""
+                 (if (opensmtpd-maildir-configuration-junk record)
+                     " junk "
+                     " ")))
+
+(define (opensmtpd-action-local-delivery-configuration->string record)
+  (let ([name (opensmtpd-action-local-delivery-configuration-name record)]
+        [method (opensmtpd-action-local-delivery-configuration-method record)]
+        [alias (if (opensmtpd-action-local-delivery-configuration-alias record)
+                   (opensmtpd-table-configuration-name
+                    (opensmtpd-action-local-delivery-configuration-alias record))
+                   #f)]
+        [ttl (opensmtpd-action-local-delivery-configuration-ttl record)]
+        [user (opensmtpd-action-local-delivery-configuration-user record)]
+        [userbase (if (opensmtpd-action-local-delivery-configuration-userbase record)
+                      (opensmtpd-table-configuration-name
+                       (opensmtpd-action-local-delivery-configuration-userbase record))
+                      #f)]
+        [virtual (if (opensmtpd-action-local-delivery-configuration-virtual record)
+                     (opensmtpd-table-configuration-name
+                      (opensmtpd-action-local-delivery-configuration-virtual record))
+                     #f)]
+        [wrapper (opensmtpd-action-local-delivery-configuration-wrapper record)])
+    (string-append
+     "\"" name "\" "
+     (cond [(string? method)
+            (string-append method " ")]
+           [(opensmtpd-mda-configuration? method)
+            (opensmtpd-mda-configuration->string method)]
+           [(opensmtpd-lmtp-configuration? method)
+            (opensmtpd-lmtp-configuration->string method)]
+           [(opensmtpd-maildir-configuration? method)
+            (opensmtpd-maildir-configuration->string method)])
+     ;; FIXME/TODO support specifying alias file:/path/to/alias-file  ?
+     ;; I do not think that is something that I can do...
+     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
+     (variable->string ttl #:append "ttl ")
+     (variable->string user #:append "user ")
+     (variable->string userbase #:append "userbase <\"" #:postpend "\"> ")
+     (variable->string virtual #:append "virtual <" #:postpend "> ")
+     (variable->string wrapper #:append "wrapper "))))
+
+;; this function turns both opensmtpd-action-local-delivery-configuration and
+;; opensmtpd-action-relay-configuration into strings.
+(define (opensmtpd-action->string record)
+  (string-append "action "
+                 (cond [(opensmtpd-action-local-delivery-configuration? record)
+                        (opensmtpd-action-local-delivery-configuration->string record)]
+                       [(opensmtpd-action-relay-configuration? record)
+                        (opensmtpd-action-relay-configuration->string record)])
+                 " \n"))
+
+;; this turns option records found in <opensmtpd-match-configuration> into strings.
+(define* (opensmtpd-option-configuration->string record
+                                                 #:key
+                                                 (space-after-! #f))
+  (let ([not (opensmtpd-option-configuration-not record)]
+        [option (opensmtpd-option-configuration-option record)]
+        [regex (opensmtpd-option-configuration-regex record)]
+        [data (opensmtpd-option-configuration-data record)])
+    (string-append
+     (if not
+         (if space-after-!
+             "! "
+             "!")
+         "")
+     option " "
+     (if regex
+         "regex "
+         "")
+     (if data
+         (if (opensmtpd-table-configuration? data)
+             (string-append "<" (opensmtpd-table-configuration-name data) "> ")
+             (string-append data " "))
+         ""))))
+
+(define (opensmtpd-match-configuration->string record)
+  (string-append "match "
+                 (let* ([action (opensmtpd-match-configuration-action record)]
+                        [name (cond [(opensmtpd-action-relay-configuration? action)
+                                     (opensmtpd-action-relay-configuration-name action)]
+                                    [(opensmtpd-action-local-delivery-configuration? action)
+                                     (opensmtpd-action-local-delivery-configuration-name action)]
+                                    [else 'reject])]
+                        [options (opensmtpd-match-configuration-options record)])
+                   (string-append
+                    (if options
+                        (apply string-append
+                               (map opensmtpd-option-configuration->string options))
+                        "")
+                    (if (string? name)
+                        (string-append "action " "\"" name "\" ")
+                        "reject ")
+                    "\n"))))
+
+(define (opensmtpd-ca-configuration->string record)
+  (string-append "ca " (opensmtpd-ca-configuration-name record) " "
+                 "cert \"" (opensmtpd-ca-configuration-file record) "\"\n"))
+
+(define (opensmtpd-pki-configuration->string record)
+  (let ([domain (opensmtpd-pki-configuration-domain record)]
+        [cert (opensmtpd-pki-configuration-cert record)]
+        [key (opensmtpd-pki-configuration-key record)]
+        [dhe (opensmtpd-pki-configuration-dhe record)])
+    (string-append "pki " domain " " "cert \"" cert "\" \n"
+                   "pki " domain " " "key \"" key "\" \n"
+                   (if dhe
+                       (string-append
+                        "pki " domain " " "dhe " dhe "\n")
+                       ""))))
+
+(define (generate-filter-chain-name list-of-filters)
+  (string-drop-right (apply string-append
+                            (flatten
+                             (map (lambda (filter)
+                                    (list
+                                     (if (opensmtpd-filter-configuration? filter)
+                                         (opensmtpd-filter-configuration-name filter)
+                                         (opensmtpd-filter-phase-configuration-name filter))
+                                     "-"))
+                                  list-of-filters)))
+                     1))
+
+;; this procedure takes in a list of <opensmtpd-filter-configuration> and <opensmtpd-filter-phase-configuration>,
+;; returns a string of the form:
+;; filter "uniquelyGeneratedName" chain chain { "filter-name", "filter-name2" [, ...]}
+(define (opensmtpd-filter-chain->string list-of-filters)
+  (string-append "filter \""
+                 (generate-filter-chain-name list-of-filters)
+                 "\" "
+                 "chain {"
+                 (string-drop-right
+                  (apply string-append
+                         (flatten
+                          (map (lambda (filter)
+                                 (list
+                                  "\""
+                                  (if (opensmtpd-filter-configuration? filter)
+                                      (opensmtpd-filter-configuration-name filter)
+                                      (opensmtpd-filter-phase-configuration-name filter))
+                                  "\", "))
+                               list-of-filters))
+                         ) 2)
+                 "}\n"))
+
+(define (opensmtpd-filter-phase-configuration->string record)
+  (let ([name (opensmtpd-filter-phase-configuration-name record)]
+        [phase (opensmtpd-filter-phase-configuration-phase record)]
+        [decision (opensmtpd-filter-phase-configuration-decision record)]
+        [options (opensmtpd-filter-phase-configuration-options record)]
+        [message (opensmtpd-filter-phase-configuration-message record)]
+        [value (opensmtpd-filter-phase-configuration-value record)])
+    (string-append "filter "
+                   "\"" name "\" "
+                   "phase " phase " "
+                   "match "
+                   (apply string-append ; turn the options into a string
+                          (flatten
+                           (map (lambda (option)
+                                  (opensmtpd-option-configuration->string option #:space-after-! #f))
+                                options)))
+                   " "
+                   decision " "
+                   (if (string-in-list? decision (list "reject" "disconnect"))
+                       (string-append "\"" message "\"")
+                       "")
+                   (if (string=? "rewrite" decision)
+                       (string-append "rewrite " (number->string value))
+                       "")
+                   "\n")))
+
+;; filters elements may be <opensmtpd-filter-configuration>, <opensmtpd-filter-phase-configuration>,
+;; and lists that look like (list (opensmtpd-filter-configuration...) (opensmtpd-filter-phase-configuration ...)
+;; ...)
+;; this function converts it to a string.
+;; Consider if a user passed in a valid <opensmtpd-configuration>, whose total valid filters
+;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
+;; look like this: (we will call this list "total filters"):
+;; (list (opensmtpd-filter
+;;         (name "rspamd")
+;;         (proc "rspamd"))
+;;       (list (opensmtpd-filter-phase-configuration ; this is a listen-on, with a filter-chain.
+;;               (name "dkimsign")
+;;               ...)
+;;               (opensmtpd-filter
+;;                 (name "rspamd")
+;;                 (proc "rspamd"))))
+;;
+;; did you notice that filter "rspamd" is listed twice?  How do you make sure that it is NOT
+;; printed twice in smtpd.conf?
+;; 1st flatten "total filters", then remove its duplicates.  Then print all of those filters.
+;; 2nd now we go through "total filters", and we only print the non-filter-chains.
+(define (opensmtpd-filters->string filters)
+  ;; first display the unique <opensmtpd-filter-configuration>s. and <opensmtpd-filter-phase-configuration>s.
+  ;; to do this: flatten filters, then remove duplicates.
+  (string-append
+   (apply string-append
+          (map (lambda (filter)
+                 (cond ((opensmtpd-filter-phase-configuration? filter)
+                        (opensmtpd-filter-phase-configuration->string filter))
+                       (else            ; you are a <opensmtpd-filter-configuration>
+                        (string-append "filter "
+                                       "\"" (opensmtpd-filter-configuration-name filter) "\" "
+                                       (if (opensmtpd-filter-exec filter)
+                                           "proc-exec "
+                                           "proc ")
+                                       "\"" (opensmtpd-filter-configuration-proc filter) "\""
+                                       "\n"))))
+               (delete-duplicates (flatten filters))))
+   ;; now we have to print the filter chains.
+   (apply string-append
+          (remove boolean?
+                  (map (lambda (filter)
+                         (cond ((list? filter)
+                                (opensmtpd-filter-chain->string filter))
+                               (else    ; you are a <opensmtpd-filter-configuration>
+                                #f)))
+                       filters)))))
+
+(define (opensmtpd-configuration-listen->string string)
+  (string-append
+   "include \"" string "\"\n"))
+
+(define (opensmtpd-configuration-srs->string record)
+  (let ([key (opensmtpd-srs-configuration-key record)]
+        [backup-key (opensmtpd-srs-configuration-backup-key record)]
+        [ttl-delay (opensmtpd-srs-configuration-ttl-delay record)])
+    (string-append
+     (variable->string key #:append "srs key " #:postpend "\n")
+     (variable->string backup-key #:append "srs key backup " #:postpend "\n")
+     (variable->string ttl-delay #:append "srs ttl " #:postpend "\n")
+     "\n")))
+
+;; TODO make sure all options here work!  I just fixed limit-max-rcpt!
+(define (opensmtpd-smtp-configuration->string record)
+  (let ([ciphers (opensmtpd-smtp-configuration-ciphers record)]
+        [limit-max-mails (opensmtpd-smtp-configuration-limit-max-mails record)]
+        [limit-max-rcpt (opensmtpd-smtp-configuration-limit-max-rcpt record)]
+        [max-message-size (opensmtpd-smtp-configuration-max-message-size record)]
+        [sub-addr-delim (opensmtpd-smtp-configuration-sub-addr-delim record)])
+    (string-append
+     (variable->string ciphers #:append "smtp ciphers " #:postpend "\n")
+     (variable->string limit-max-mails #:append "smtp limit max-mails " #:postpend "\n")
+     (variable->string limit-max-rcpt #:append "smtp limit max-rcpt " #:postpend "\n")
+     (variable->string max-message-size #:append "smtp max-message-size " #:postpend "\n")
+     (variable->string sub-addr-delim #:append "smtp sub-addr-delim " #:postpend "\n")
+     "\n")))
+
+(define (opensmtpd-configuration-queue->string record)
+  (let ([compression (opensmtpd-queue-configuration-compression record)]
+        [encryption (opensmtpd-queue-configuration-encryption record)]
+        [ttl-delay (opensmtpd-queue-configuration-ttl-delay record)])
+    (string-append
+     (if compression
+         "queue compression\n"
+         "")
+     (if encryption
+         (string-append
+          "queue encryption "
+          (if (not (boolean? encryption))
+              encryption
+              "")
+          "\n")
+         "")
+     (if ttl-delay
+         (string-append "queue ttl" ttl-delay "\n")
+         ""))))
+
+;; build a list of <opensmtpd-action> from
+;; opensmtpd-configuration-matches, which is a list of <opensmtpd-match-configuration>.
+;; Each <opensmtpd-match-configuration> has a fieldname 'action', which accepts an <opensmtpd-action>.
+(define (get-opensmtpd-actions record)
+  (define opensmtpd-actions
+    (let loop ([list (opensmtpd-configuration-matches record)])
+      (if (null? list)
+          '()
+          (cons (opensmtpd-match-configuration-action (car list))
+                (loop (cdr list))))))
+  (delete-duplicates (append opensmtpd-actions)))
+
+;; build a list of opensmtpd-pki-configurations from
+;; opensmtpd-configuration-listen-ons and
+;; get-opensmtpd-actions
+(define (get-opensmtpd-pki-configurations record)
+  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT have an opensmtpd-action-relay-configuration?
+  ;; I think so.  And if it did NOT have a relay configuration, then action-pkis would be '() when
+  ;; it needs to be #f.  because if the opensmtpd-configuration has NO pkis, then this function will
+  ;; return '(), when it should return #f.  If it returns '(), then opensmtpd-configuration-fieldname->string will
+  ;; print the string "\n" instead of ""
+  (define action-pkis
+    (let loop1 ([list (get-opensmtpd-actions record)])
+      (if (null? list)
+          '()
+          (if (and (opensmtpd-action-relay-configuration? (car list))
+                   (opensmtpd-action-relay-configuration-pki (car list)))
+              (cons (opensmtpd-action-relay-configuration-pki (car list))
+                    (loop1 (cdr list)))
+              (loop1 (cdr list))))))
+  ;; FIXME/TODO/maybe/wishlist
+  ;; this could be #f aka left blank. aka there are no listen-ons records with pkis.
+  ;; aka there are no lines in the configuration like:
+  ;; listen on eth0 tls pki smtp.gnucode.me in that case the smtpd.conf will have an extra "\n"
+  (define listen-on-pkis
+    (let loop2 ([list (opensmtpd-configuration-listen-ons record)])
+      (if (null? list)
+          '()
+          (if (opensmtpd-listen-on-configuration-pki (car list))
+              (cons (opensmtpd-listen-on-configuration-pki (car list))
+                    (loop2 (cdr list)))
+              (loop2 (cdr list))))))
+  (delete-duplicates (append action-pkis listen-on-pkis)))
+
+;; takes in a <opensmtpd-configuration> and returns a list whose elements are <opensmtpd-filter-configuration>,
+;; <opensmtpd-filter-phase-configuration>, and a filter-chain.
+;; It returns a list of <opensmtpd-filter-configuration> and/or <opensmtpd-filter-phase-configuration>
+;; here's an example of what this procedure might return:
+;; (list (opensmtpd-filter-configuration...) (opensmtpd-filter-phase-configuration ...)
+;;       (openmstpd-filter ...) (opensmtpd-filter-phase-configuration ...)
+;;       ;; this next list is a filter-chain.
+;;       (list (opensmtpd-filter-phase-configuration ...) (opensmtpd-filter-configuration...)))
+;;
+;; This procedure handles filter chains a little odd.
+(define (get-opensmtpd-filters record)
+  (define list-of-listen-on-records (if (opensmtpd-configuration-listen-ons record)
+                                        (opensmtpd-configuration-listen-ons record)
+                                        '()))
+
+  (define listen-on-socket-filters
+    (if (opensmtpd-listen-on-socket-configuration-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        (opensmtpd-listen-on-socket-configuration-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        '()))
+
+    (delete-duplicates
+     (append (remove boolean?
+                     (map-in-order (lambda (listen-on-record) ; get the filters found in the <listen-on-record>s
+                                     (if (and (opensmtpd-listen-on-configuration-filters listen-on-record)
+                                              (= 1 (length (opensmtpd-listen-on-configuration-filters
+                                                            listen-on-record))))
+                                         (car (opensmtpd-listen-on-configuration-filters listen-on-record))
+                                         (opensmtpd-listen-on-configuration-filters listen-on-record)))
+                                   list-of-listen-on-records))
+             listen-on-socket-filters)))
+
+(define (flatten . lst)
+  "Return a list that recursively concatenates all sub-lists of LST."
+  (define (flatten1 head out)
+    (if (list? head)
+        (fold-right flatten1 out head)
+        (cons head out)))
+  (fold-right flatten1 '() lst))
+
+;; This function takes in a record, or list, or anything, and returns
+;; a list of <opensmtpd-table-configuration>s assuming the thing you passed into it had
+;; any <opensmtpd-table-configuration>s.
+;;
+;; is object record? call func on it's fieldnames
+;; is object list? loop through it's fieldnames calling func on it's records
+;; is object #f or string? or '()? -> #f
+(define (get-opensmtpd-tables value)
+  (delete-duplicates
+   (remove boolean? (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+               (cond ((opensmtpd-table-configuration? value)
+                      value)
+                     ((record? value)
+                      (let* ([record-type (record-type-descriptor value)]
+                             [list-of-record-fieldnames (record-type-fields record-type)])
+                        (map (lambda (fieldname)
+                               (get-opensmtpd-tables ((record-accessor record-type fieldname) value)))
+                             list-of-record-fieldnames)))
+                     ((and (list? value) (not (null? value)))
+                      (map get-opensmtpd-tables value))
+                     (else #f))))))
+
+(define (opensmtpd-configuration-fieldname->string record fieldname-accessor record->string)
+  (if (fieldname-accessor record)
+      (begin
+        (string-append
+         (list-of-records->string (fieldname-accessor record) record->string) "\n"))
+      ""))
+
+(define (list-of-records->string list-of-records record->string)
+  (string-append
+   (cond [(not (list? list-of-records))
+          (record->string list-of-records)]
+         [else
+          (let loop ([list list-of-records])
+            (if (null? list)
+                ""
+                (string-append
+                 (record->string (car list))
+                 (loop (cdr list)))))])))
+
+
+;; FIXME/TODO should I use format here srfi-28 ?
+;; web.scm nginx does a (format #f "string" "another string")
+;; this could be a list like (list (file-append opensmtpd-dkimsign "/libexec/filter") "-d gnucode.me -s /path/to/selector.cert")
+;; Then opensmtpd-configuration->mixed-text-file could be rewritten to be something like
+;; (mixed-text-file (eval `(string-append (opensmtpd-configuration-fieldname->string ...)) (gnu services mail)))
+(define (opensmtpd-configuration->mixed-text-file record)
+  ;; should I use this named let, or should I give this a name, or not use it at all...
+  ;; eg: (write-all-fieldnames (list (cons fieldname fieldname->string) (cons fieldname2 fieldname->string)))
+  ;; (let loop ([list (list (cons opensmtpd-configuration-includes (lambda (string)
+  ;;                                                                 (string-append
+  ;;                                                                  "include \"" string "\"\n")))
+  ;;                        (cons opensmtpd-configuration-smtp opensmtpd-smtp->string)
+  ;;                        (cons opensmtpd-configuration-srs opensmtpd-srs->string))])
+  ;;   (if (null? list)
+  ;;       ""
+  ;;       (string-append (opensmtpd-configuration-fieldname->string record
+  ;;                                                                 (caar list)
+  ;;                                                                 (cdar list))
+  ;;                      (loop (cdr list)))))
+
+  ;;(mixed-text-file "opensmtpd.conf")
+  (string-append
+   ;; write out the includes
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-includes
+                                              opensmtpd-configuration-listen->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-bounce
+                                              (lambda (%bounce)
+                                                (if %bounce
+                                                    (list-of-strings->string %bounce)
+                                                    "")))
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-smtp
+                                              opensmtpd-smtp-configuration->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-srs
+                                              opensmtpd-configuration-srs->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-queue
+                                              opensmtpd-configuration-queue->string)
+   ;; write out the mta-max-deferred
+   (opensmtpd-configuration-fieldname->string
+    record opensmtpd-configuration-mta-max-deferred
+    (lambda (var)
+      (string-append "mta max-deferred "
+                     (number->string (opensmtpd-configuration-mta-max-deferred record)) "\n")))
+   ;;write out all the tables
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-tables opensmtpd-table-configuration->string)
+   ;; TODO should I change the below line of code into these two lines of code?
+   ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-filter-phase->string)
+   ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
+   ;; write out all the filters
+   (opensmtpd-filters->string (get-opensmtpd-filters record))
+   ;; write out all the cas
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-cas opensmtpd-ca-configuration->string)
+   ;; write out all the pkis
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-pki-configurations opensmtpd-pki-configuration->string)
+   ;; write all of the listen-on-records
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-ons
+                                              opensmtpd-listen-on-configuration->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-on-socket
+                                              opensmtpd-listen-on-socket-configuration->string)
+   ;; write all the actions
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-actions
+                                              opensmtpd-action->string)
+   ;; write all of the matches
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-matches opensmtpd-match-configuration->string)))
+
 
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "
-- 
2.36.1





^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] gnu: services: opensmtpd-records-task-list.org: Some notes about how I thought about building this service. And some additional task lists, as well as the WIP documentation.
  2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
@ 2022-06-17 21:54 ` Joshua Branson via Guix-patches via
  2022-07-04 21:17 ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2 Joshua Branson via Guix-patches via
                   ` (4 subsequent siblings)
  5 siblings, 0 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-06-17 21:54 UTC (permalink / raw)
  To: 56046; +Cc: Joshua Branson

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 216272 bytes --]

---
 gnu/services/opensmtpd-records-task-list.org | 5122 ++++++++++++++++++
 1 file changed, 5122 insertions(+)
 create mode 100644 gnu/services/opensmtpd-records-task-list.org

diff --git a/gnu/services/opensmtpd-records-task-list.org b/gnu/services/opensmtpd-records-task-list.org
new file mode 100644
index 0000000000..c138aab8fe
--- /dev/null
+++ b/gnu/services/opensmtpd-records-task-list.org
@@ -0,0 +1,5122 @@
+#+title: Opensmtpd Records Task List
+#+AUTHOR: Joshua Branson
+
+
+(service (@ (gnu services mail) opensmtpd-service-type)
+             ((@ (gnu services mail) opensmtpd-configuration)
+              (config-file …)))
+
+* tasks
+** PROJ I have decent data structures. now let's get some good code. [0/6]
+*** why are good data structures important?
+**** nckx's advice: use a simple 1-1 mapping
+"...as I think Guix services ought to faithfully wrap the native
+syntax whenever possible (implement alternative simple APIs on top of
+that — fine)."
+
+-nckx from irc on #guix
+
+**** To follow nckx's advice, one might create the =<opensmtpd-service>= like this:
+#+BEGIN_SRC scheme
+  (service opensmtpd-service
+           (opensmtpd-configuration
+            (includes ...)
+            (tables ...)
+            (pkis ...)
+            (filters ...)
+            (listen-on ...)
+            (actions ...)
+            (matches ...)))
+#+END_SRC
+
+Defining the service this way, makes it VERY easy from a development point of
+view.  But it makes it possible for users to create simple mistakes when
+defining the service.
+
+For example, it is possible to define an nginx service that will successfully
+reconfigure the system. BUT after reboot nginx refuses to start. Why? Who knows.
+Guix won't tell you. Neither will the Shepherd. To fix this, the user has to go
+digging into the nginx logs, and he might not know where to find those. If
+possible, when the user specificies a =<opensmtpd-configuration>= that has
+obvious errors, then the guix services should make reconfigure fail and print a
+helpful error message.
+
+**** BUT it would be better if the service uses better datastructures.
+
+I should follow nckx's advice, and Linus' advice: good programmers use good
+datastructures. If you have good datastructures, then your code will almost
+write itself.
+
+It might make the service a little harder to develop, but end-users will find
+the service easier to use. This would eliminate common errors like misspellings
+and give appropriate error messages. Practically it would ensure each
+=<opensmtpd-match-configuration>= has a corresponding =<opensmtpd-action>=,
+creating a table name and then misspelling the table name later, and defining
+a table but never using it, etc.
+
+**** Example configuration
+
+#+BEGIN_SRC scheme
+(service opensmtpd-service-type
+         (let ([interface "lo"]
+               [creds-table (opensmtpd-table-configuration
+                             (name "creds")
+                             (data
+                              (list
+                               (cons "joshua"
+                                     "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))))]
+               [receive-action (opensmtpd-action-local-delivery-configuration
+                                (name "receive")
+                                (method (opensmtpd-maildir-configuration
+                                         (pathname "/home/%{rcpt.user}/Maildir")
+                                         (junk #t)))
+                                (virtual (opensmtpd-table-configuration
+                                          (name "virtual")
+                                          (data (list "josh" "jbranso@dismail.de")))))]
+               [filter-dkimsign (opensmtpd-filter-configuration
+                                 (name "dkimsign")
+                                 (exec #t)
+                                 (proc (string-append "/path/to/dkimsign  -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                                                      "/path/to/dkimsign-key user nobody group nobody")))]
+               [smtp.gnucode.me (opensmtpd-pki-configuration
+                                 (domain "smtp.gnucode.me")
+                                 (cert "opensmtpd.scm")
+                                 (key "opensmtpd.scm"))])
+           (opensmtpd-configuration
+            (mta-max-deferred 50)
+            (queue
+             (opensmtpd-queue-configuration
+              (compression #t)))
+            (smtp
+             (opensmtpd-smtp-configuration
+              (max-message-size "10M")))
+            (srs
+             (opensmtpd-srs-configuration
+              (ttl-delay "5d")))
+            (listen-ons
+             (list
+              (opensmtpd-listen-on-configuration
+               (interface interface)
+               (port 25)
+               (secure-connection "tls")
+               (filters (list (opensmtpd-filter-phase-configuration
+                               (name "noFRDNS")
+                               (phase "commit")
+                               (options (list (opensmtpd-option-configuration
+                                                  (option "fcrdns")
+                                                  (not #t))))
+                               (decision "disconnect")
+                               (message "433 No FCRDNS"))))
+               (pki smtp.gnucode.me))
+              ;; this lets local users logged into the system via ssh send email
+              (opensmtpd-listen-on-configuration
+               (interface interface)
+               (port 465)
+               (secure-connection "smtps")
+               (pki smtp.gnucode.me)
+               (auth creds-table)
+               (filters (list filter-dkimsign)))
+              (opensmtpd-listen-on-configuration
+               (interface interface)
+               (port 587)
+               (secure-connection "tls-require")
+               (pki smtp.gnucode.me)
+               (auth creds-table)
+               (filters (list filter-dkimsign)))))
+            (matches (list
+                      (opensmtpd-match-configuration
+                       (action (opensmtpd-action-relay-configuration
+                                (name "relay")))
+                       (options (list (opensmtpd-option-configuration
+                                       (option "for any"))
+                                      (opensmtpd-option-configuration
+                                       (option "from any"))
+                                      (opensmtpd-option-configuration
+                                       (option "auth")))))
+                      (opensmtpd-match-configuration
+                       (action receive-action)
+                       (options (list (opensmtpd-option-configuration
+                                       (option "from any"))
+                                      (opensmtpd-option-configuration
+                                       (option "for domain")
+                                       (data (opensmtpd-table-configuration
+                                              (name "domain-table")
+                                              (data (list "gnucode.me" "gnu-hurd.com"))))))))
+                      (opensmtpd-match-configuration
+                       (action receive-action)
+                       (options (list (opensmtpd-option-configuration
+                                       (option "for local"))))))))))
+#+END_SRC
+
+:OldConfigurationSyntax:
+#+BEGIN_SRC scheme
+  (service opensmtpd-service-type
+               (opensmtpd-configuration
+                (pkis (list
+                       (opensmtpd-pki-configuration
+                        ...)))
+                (tables (list
+                         (opensmtpd-table-configuration
+                          ...)
+                         (opensmtpd-table-configuration
+                          ...)))
+                (listen-ons
+                 (list
+                  (opensmtpd-listen-on-configuration
+                   ...)
+                  (opensmtpd-listen-on-configuration
+                   ...)))
+                (actions
+                 (list
+                  (opensmtpd-action
+                     ...)
+                  (opensmtpd-action
+                   ...)))
+                (matches (list
+                          (opensmtpd-match-configuration
+                           ...)
+                          (opensmtpd-match-configuration
+                           ...)))
+                (filter-chains
+                 (list
+                  (opensmtpd-filter-chain
+                   (name "dropDumbEmails")
+                   (filter-names (list "nofcrdnsDisconnect"
+                                       "nordnsDisconnect")))))
+                (filter-phases
+                 (list (opensmtpd-filter-phase-configuration
+                        ...)
+                       (opensmtpd-filter-phase-configuration
+                        ...)))))
+#+END_SRC
+
+Here you have to define the =pki=s twice!  You define it once in the =pkis=
+section, and then you reference it later.  This could potentially cause a
+mispelling error.  That would be silly to debug as an end-user.
+
+:END:
+
+*** PROJ tweek the code for =<opensmtpd-filter-configuration>= & =<opensmtpd-filter-phase-configuration>= records [4/7]
+**** Why I chose the current datastructures of =<opensmtpd-filter-configuration>= & =<opensmtpd-filter-phase-configuration>=
+
+According to the man page I have a four kinds of filters:
+
+#+BEGIN_EXAMPLE
+1. filter chain-name chain {filter-name [, ...]}
+         Register a chain of filters chain-name, consisting of the filters listed from filter-name.
+         Filters part of a filter chain are executed in order of declaration for each phase that
+         they are registered for.  A filter chain may be used in place of a filter for any direc‐
+         tive but filter chains themselves.
+2. filter filter-name phase phase-name match conditions decision
+         Register a filter filter-name.  A decision about what to do with the mail is taken at
+         phase phase-name when matching conditions.  Phases, matching conditions, and decisions are
+         described in MAIL FILTERING, below.
+3. filter filter-name proc proc-name
+         Register "proc" filter filter-name backed by the proc-name process.
+4. filter filter-name proc-exec command
+         Register and execute "proc" filter filter-name from command.  If command starts with a
+         slash it is executed with an absolute path, else it will be run from
+         “/gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/libexec/opensmtpd”.
+#+END_EXAMPLE
+
+=chain-name= could be easily represented as a list of filters. in the
+opensmtpd-configuration-filter fieldname:
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (listen-on
+  (filter
+   (list (opensmtpd-filter-configuration)
+         (opensmtpd-filter-configuration)
+         (opensmtpd-filter-configuration)))))
+#+END_SRC
+
+For example, this is probably easier
+
+#+BEGIN_SRC scheme
+  (opensmtpd-configuration
+   (actions (list
+             (opensmtpd-action
+              (name "relay")
+              (method (opensmtpd-relay-configuration
+                       (domain (opensmtpd-table-configuration
+                                ;;(name "domains")  ;; with some smart coding, the name would NOT be needed.
+                                (data (list
+                                         "gnucode.me"
+                                         "gnu-hurd.com"))))))))))
+#+END_SRC
+
+than the alternative:
+
+#+BEGIN_SRC scheme
+  (opensmtpd-configuration
+   (tables (list
+            (opensmtpd-table-configuration
+             (name "domains")
+             (data (list
+                      "gnucode.me"
+                      "gnu-hurd.com")))))
+   (actions (list
+             (opensmtpd-action
+              (name "relay")
+              (method (opensmtpd-relay-configuration
+                       (domain "domains")))))))
+#+END_SRC
+
+**** some example code for each of the 3 types of filters
+
+1. filter phase
+#+BEGIN_SRC scheme
+(opensmtpd-filter-phase-configuration
+ (name "phase")
+ (phase "connect")
+ (options
+  (list
+   (opensmtpd-option-configuration
+    (option "src")
+    (not #t)
+    (regex #t)
+    (table (opensmtpd-table-configuration (name "src-option-table")
+                            (data (list "cat" "hot")))))))
+ (decision "reject")
+ (message "We do not want spam here!"))
+#+END_SRC
+
+#+RESULTS:
+
+2. filter proc
+this is a filter-proc
+#+BEGIN_SRC scheme
+(opensmtpd-filter
+ (name "proc")
+ (proc "dkimsign"))
+#+END_SRC
+
+3. filter proc-exec
+#+BEGIN_SRC scheme
+(opensmtpd-filter
+ (name "proc")
+ (exec #t)
+ (proc "dkimsign"))
+#+END_SRC
+
+***** Why am I doing the data structure like the above?
+
+filter-proc and proc-exec as defined in man smtpd.conf can both use the same
+<opensmtpd-filter-configuration> record.  That works just fine.
+
+But filter-phase is a different beast.  I do NOT want someone to accidentally
+define something like the following which is BAD data:
+
+#+BEGIN_SRC scheme
+(opensmtpd-filter
+ (name "proc")
+ (exec #t)
+ (proc "dkimsign"))
+
+#+END_SRC
+**** NO Is it advantageous/desireable to merge =<opensmtpd-filter-configuration>= & <opensmtpd-filter-phase-configuration>
+
+When a user creates a filter, he is either going to create a
+=<opensmtpd-filter-configuration>~ or an ~<opensmtpd-filter-phase>= NOT both. If
+we define separate records, then it is impossible for a user to accidentally
+define a filter record using fieldnames from both filter types. eg:
+
+#+BEGIN_SRC scheme
+(opensmtpd-filter-configuration
+ (name "filter")
+ (exec #t)
+ (proc "dkimsign")
+ (phase "connect"))  ;; this phase should NOT be there. this is a <opensmtpd-filter-configuration>
+#+END_SRC
+
+If =<opensmtpd-filter-configuration>= & =<opensmtpd-filter-phase-configuration>= are separte then the above
+would correctly result in an error message for free.
+**** TODO make <opensmtpd-filter-configuration> fieldname 'proc' accept a list of strings and/or a <gexp>s
+
+Suppose you want to do dkimsigning in smtpd.conf.  Here is how you might
+register the official opensmtpd dkimsign filter:
+
+#+BEGIN_EXAMPLE
+filter "dkimsign" proc-exec "filter-dkimsign -d <domain> -s <selector>  \
+       -k /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/dkim/private.key" user _dkimsign group _dkimsign
+#+END_EXAMPLE
+
+For example my hacky code to do dkimsigning looks like:
+
+#+BEGIN_SRC scheme
+filter \"dkimsign\"  \
+  proc-exec \"" path-to-filter-dkimsign " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k " etc-dkimsign-key-file
+  " \"  \
+  user nobody group nogroup
+
+#+END_SRC
+
+Here is some example code of how we could create an
+=<opensmtpd-filter-configuration>= that registers a dkimsign filter.  The code
+below probably will NOT work.
+
+#+BEGIN_SRC scheme
+(let ((etc-dkimsign-key-file "filename.key")
+      (path-to-dkimsign-key "/etc/opensmtpd/")))
+(opensmtpd-filter-configuration
+ (name "dkimsign")
+ (proc (list
+        (file-append opensmtpd-filter-dkimsign "/libexec/opensmtpd/filter-dkimsign")
+        " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+        ~#(let ([UID-nobody (passwd:uid (getpw "nobody"))]
+                [GID-root (group:gid (getgr "root"))]
+                [GID-nogroup (group:gid (getgr "nogroup"))])
+            ;; #o550 user root can read/open the directory
+            ;; and the group "root" can read/open the directory.
+            ;; change these two lines to (mkdir-p) ?
+            (unless (file-exists? "/etc/opensmtpd")
+              (mkdir "/etc/opensmtpd" #o550))
+
+            ;; root can read/write/execute on directory dkimsign
+            ;; group "root" can read and execute
+            (unless (file-exists? "/etc/opensmtpd/dkimsign")
+              (mkdir "/etc/opensmtpd/dkimsign" #o750))
+
+            (copy-file path-to-dkimsign-key etc-dkimsign-key-file)
+            ;; make the etc-dkimsign-key-file to owned by nobody and group nogroup.
+            (chown "/etc/opensmtpd" UID-nobody GID-root)
+            (chown "/etc/opensmtpd/dkimsign" UID-nobody GID-root)
+            (chown etc-dkimsign-key-file UID-nobody GID-nogroup)
+            "/etc/opensmtpd/dkimsign/2021-09-22-rsa1024-gnucode.me.key")
+        "user nobody group nogroup"))
+ (exec #))
+#+END_SRC
+
+Here is the full for how I currently run opensmtpd:
+
+#+BEGIN_SRC sh :dir ~/prog/gnu/guix/guix-config/linode-guix-system-configuration/ :results raw
+cat opensmtpd.scm
+#+END_SRC
+
+#+RESULTS:
+#+BEGIN_SRC scheme
+(define-module (opensmtpd)
+  #:use-module (guix gexp)
+  #:use-module (guix records)
+  #:use-module (gnu packages mail) ;;for finding location of filter-dkimsign
+  #:export (
+            %smtpd.conf
+            ))
+
+
+;; to create credentials for now, I need to do the following:
+;;  find /gnu/store -name '*encrypt*' | grep opensmtpd
+;; /gnu/store/blah/opensmtpd/encrypt
+(define creds
+  (plain-file "creds"
+              ;; this is my joshua's password for server.  This can be found on dobby's /home/joshua/.authinfo/
+              "joshua $6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))
+
+(define vdoms
+  (plain-file
+   "vdoms"
+   "gnucode.me
+gnu-hurd.com"))
+
+(define vusers
+  (plain-file
+   "vusers"
+   "joshua@gnucode.me  joshua
+jbranso@gnucode.me     joshua
+postmaster@gnucode.me  joshua"))
+
+(define path-to-filter-dkimsign
+  (file-append opensmtpd-filter-dkimsign "/libexec/opensmtpd/filter-dkimsign"))
+
+(define path-to-dkimsign-key (string-append (getcwd) "/email-dkim-ssh-keys/2021-09-22-rsa1024-gnucode.me.key"))
+(define etc-dkimsign-key-file "/etc/opensmtpd/dkimsign/2021-09-22-rsa1024-gnucode.me.key")
+
+;; FIXME:  This should become a derivation.  Currently it just runs when I evaluate
+;; %smtpd.conf.  For example it should look like this?
+;; (define build-exp
+;;   #~(begin
+;;       (mkdir #$output)
+;;       (chdir #$output)
+;;       (symlink (string-append #$coreutils "/bin/ls")
+;;                "list-files")))
+
+;; I will need to extend the opensmtpd service, to create a directory
+;; in etc.  This line needs to be added to etc-service.
+;; (service-extension etc-service-type opensmtpd-etc-service)
+;; I'll then need to create a opensmtpd-etc-service procedure.  ganeti has
+;; a good example.
+
+;; It should also use the /etc service, which is a service for creating
+;; directories and files in /etc ?
+(define (create-etc-dkimsign-key-file)
+  #~(let ([UID-nobody (passwd:uid (getpw "nobody"))]
+          [GID-root (group:gid (getgr "root"))]
+          [GID-nogroup (group:gid (getgr "nogroup"))])
+    ;; #o550 user root can read/open the directory
+    ;; and the group "root" can read/open the directory.
+    ;; change these two lines to (mkdir-p) ?
+      (unless (file-exists? "/etc/opensmtpd")
+        (mkdir "/etc/opensmtpd" #o550))
+
+      ;; root can read/write/execute on directory dkimsign
+      ;; group "root" can read and execute
+      (unless (file-exists? "/etc/opensmtpd/dkimsign")
+        (mkdir "/etc/opensmtpd/dkimsign" #o750))
+
+      (copy-file path-to-dkimsign-key etc-dkimsign-key-file)
+      ;; ;; ;; make the etc-dkimsign-key-file to owned by nobody and group nogroup.
+      (chown "/etc/opensmtpd" UID-nobody GID-root)
+      (chown "/etc/opensmtpd/dkimsign" UID-nobody GID-root)
+      (chown etc-dkimsign-key-file UID-nobody GID-nogroup)
+      etc-dkimsign-key-file))
+
+(define %smtpd.conf
+  (mixed-text-file "smtpd.conf"
+                   "
+# This is the smtpd server system-wide configuration file.
+# See smtpd.conf(5) for more information.
+# borrowed from the archlinux guix
+# https://wiki.archlinux.org/index.php/OpenSMTPD#Simple_OpenSMTPD/mbox_configuration
+
+# My TLS certificate and key
+table aliases file:/etc/aliases
+pki smtp.gnucode.me cert \"/etc/letsencrypt/live/gnucode.me/fullchain.pem\"
+pki smtp.gnucode.me key \"/etc/letsencrypt/live/gnucode.me/privkey.pem\"
+
+# for now I am NOT using the virtual credentials
+# table creds { joshua = $6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86. }
+table creds \"" creds "\"
+table vdoms \"" vdoms "\"
+# table vdoms { gnucode.me, gnu-hurd.com }
+# table vusers { joshua@gnucode.me = joshua, jbranso@gnucode.me = joshua, postmaster@gnucode.me = joshua }
+table vusers \"" vusers "\"
+
+# this totally works!  run this as user nobody!
+# info about dkimsign ...ing
+# https://openports.pl/path/mail/opensmtpd-filters/dkimsign
+# sudo -u nobody /gnu/store/g17vdv4l03bacn7qbdpb5v8l8vgdxcld-opensmtpd-filter-dkimsign-0.5/libexec/opensmtpd/filter-dkimsign -d gnucode.me -s 2020 -c relaxed/relaxed -k etc-dkimsign-key-file /home/joshua/linode-guix-system-configuration/email-dkim-ssh-keys/20201004-gnucode.me.key user nobody group nogroup
+
+filter \"dkimsign\"  \
+  proc-exec \"" path-to-filter-dkimsign " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k " etc-dkimsign-key-file ;;(create-etc-dkimsign-key-file)
+  " \"  \
+  user nobody group nogroup
+
+# port 25 is used only for receiving from external servers, and they may start a
+# TLS session if the want.
+listen on eth0 port 25 tls pki smtp.gnucode.me
+
+# For sending messages from outside of this server, you need to authenticate and use
+# TLS
+listen on eth0 port 465 smtps pki smtp.gnucode.me auth <creds> filter \"dkimsign\"
+listen on eth0 port 587 tls-require pki smtp.gnucode.me auth <creds> filter \"dkimsign\"
+
+# users logged-in/ssh-ed into the system can send email
+listen on lo port 25 tls pki smtp.gnucode.me
+
+# receive email action
+action \"receive\" maildir \"/home/%{rcpt.user}/Maildir\" junk virtual <vusers>
+# action send the email to the world
+action \"send\" relay
+
+# We accept to send email from any mail from authenticated users
+match for any from any auth action \"send\"
+
+#finally we receive any incoming email
+# maybe the next \"from any\" should be changed to \"for rdns\".
+match from any for domain <vdoms> action \"receive\"
+match for local action \"receive\""))
+(define-module (opensmtpd)
+  #:use-module (guix gexp)
+  #:use-module (guix records)
+  #:use-module (gnu packages mail) ;;for finding location of filter-dkimsign
+  #:export (
+            %smtpd.conf
+            ))
+
+
+;; to create credentials for now, I need to do the following:
+;;  find /gnu/store -name '*encrypt*' | grep opensmtpd
+;; /gnu/store/blah/opensmtpd/encrypt
+(define creds
+  (plain-file "creds"
+              ;; this is my joshua's password for server.  This can be found on dobby's /home/joshua/.authinfo/
+              "joshua $6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))
+
+(define vdoms
+  (plain-file
+   "vdoms"
+   "gnucode.me
+gnu-hurd.com"))
+
+(define vusers
+  (plain-file
+   "vusers"
+   "joshua@gnucode.me  joshua
+jbranso@gnucode.me     joshua
+postmaster@gnucode.me  joshua"))
+
+(define path-to-filter-dkimsign
+  (file-append opensmtpd-filter-dkimsign "/libexec/opensmtpd/filter-dkimsign"))
+
+(define path-to-dkimsign-key (string-append (getcwd) "/email-dkim-ssh-keys/2021-09-22-rsa1024-gnucode.me.key"))
+(define etc-dkimsign-key-file "/etc/opensmtpd/dkimsign/2021-09-22-rsa1024-gnucode.me.key")
+
+;; FIXME:  This should become a derivation.  Currently it just runs when I evaluate
+;; %smtpd.conf.  For example it should look like this?
+;; (define build-exp
+;;   #~(begin
+;;       (mkdir #$output)
+;;       (chdir #$output)
+;;       (symlink (string-append #$coreutils "/bin/ls")
+;;                "list-files")))
+
+;; I will need to extend the opensmtpd service, to create a directory
+;; in etc.  This line needs to be added to etc-service.
+;; (service-extension etc-service-type opensmtpd-etc-service)
+;; I'll then need to create a opensmtpd-etc-service procedure.  ganeti has
+;; a good example.
+
+;; It should also use the /etc service, which is a service for creating
+;; directories and files in /etc ?
+(define (create-etc-dkimsign-key-file)
+  #~(let ([UID-nobody (passwd:uid (getpw "nobody"))]
+          [GID-root (group:gid (getgr "root"))]
+          [GID-nogroup (group:gid (getgr "nogroup"))])
+    ;; #o550 user root can read/open the directory
+    ;; and the group "root" can read/open the directory.
+    ;; change these two lines to (mkdir-p) ?
+      (unless (file-exists? "/etc/opensmtpd")
+        (mkdir "/etc/opensmtpd" #o550))
+
+      ;; root can read/write/execute on directory dkimsign
+      ;; group "root" can read and execute
+      (unless (file-exists? "/etc/opensmtpd/dkimsign")
+        (mkdir "/etc/opensmtpd/dkimsign" #o750))
+
+      (copy-file path-to-dkimsign-key etc-dkimsign-key-file)
+      ;; ;; ;; make the etc-dkimsign-key-file to owned by nobody and group nogroup.
+      (chown "/etc/opensmtpd" UID-nobody GID-root)
+      (chown "/etc/opensmtpd/dkimsign" UID-nobody GID-root)
+      (chown etc-dkimsign-key-file UID-nobody GID-nogroup)
+      etc-dkimsign-key-file))
+
+(define %smtpd.conf
+  (mixed-text-file "smtpd.conf"
+                   "
+# This is the smtpd server system-wide configuration file.
+# See smtpd.conf(5) for more information.
+# borrowed from the archlinux guix
+# https://wiki.archlinux.org/index.php/OpenSMTPD#Simple_OpenSMTPD/mbox_configuration
+
+# My TLS certificate and key
+table aliases file:/etc/aliases
+pki smtp.gnucode.me cert \"/etc/letsencrypt/live/gnucode.me/fullchain.pem\"
+pki smtp.gnucode.me key \"/etc/letsencrypt/live/gnucode.me/privkey.pem\"
+
+# for now I am NOT using the virtual credentials
+# table creds { joshua = $6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86. }
+table creds \"" creds "\"
+table vdoms \"" vdoms "\"
+# table vdoms { gnucode.me, gnu-hurd.com }
+# table vusers { joshua@gnucode.me = joshua, jbranso@gnucode.me = joshua, postmaster@gnucode.me = joshua }
+table vusers \"" vusers "\"
+
+# this totally works!  run this as user nobody!
+# info about dkimsign ...ing
+# https://openports.pl/path/mail/opensmtpd-filters/dkimsign
+# sudo -u nobody /gnu/store/g17vdv4l03bacn7qbdpb5v8l8vgdxcld-opensmtpd-filter-dkimsign-0.5/libexec/opensmtpd/filter-dkimsign -d gnucode.me -s 2020 -c relaxed/relaxed -k etc-dkimsign-key-file /home/joshua/linode-guix-system-configuration/email-dkim-ssh-keys/20201004-gnucode.me.key user nobody group nogroup
+
+filter \"dkimsign\"  \
+  proc-exec \"" path-to-filter-dkimsign " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k " etc-dkimsign-key-file ;;(create-etc-dkimsign-key-file)
+  " \"  \
+  user nobody group nogroup
+
+# port 25 is used only for receiving from external servers, and they may start a
+# TLS session if the want.
+listen on eth0 port 25 tls pki smtp.gnucode.me
+
+# For sending messages from outside of this server, you need to authenticate and use
+# TLS
+listen on eth0 port 465 smtps pki smtp.gnucode.me auth <creds> filter \"dkimsign\"
+listen on eth0 port 587 tls-require pki smtp.gnucode.me auth <creds> filter \"dkimsign\"
+
+# users logged-in/ssh-ed into the system can send email
+listen on lo port 25 tls pki smtp.gnucode.me
+
+# receive email action
+action \"receive\" maildir \"/home/%{rcpt.user}/Maildir\" junk virtual <vusers>
+# action send the email to the world
+action \"send\" relay
+
+# We accept to send email from any mail from authenticated users
+match for any from any auth action \"send\"
+
+#finally we receive any incoming email
+# maybe the next \"from any\" should be changed to \"for rdns\".
+match from any for domain <vdoms> action \"receive\"
+match for local action \"receive\""))
+
+#+END_SRC
+**** TODO what does rewrite needs value mean?  Should it be a number?  this is for =<opensmtpd-filter-phase-configuration>=
+from the documentation
+
+rewrite value            the command parameter is rewritten with value
+**** DONE sanitize the <opensmtpd-listen-on-socket-configuration> fieldname 'filters'.
+
+I can probably reuse existing code from the sanitize procedure found in
+=<opensmtpd-listen-on-configuration>= fieldname 'filters'.
+**** DONE write a get-opensmtpd-filters procedure
+
+This procedure takes all the values of <opensmtpd-listen-on-configuration> fieldname 'filters'
+and <opensmtpd-listen-on-socket-configuration> fieldname 'filters'.  It returns a list of
+<opensmtpd-filter-configuration>, <opensmtpd-filter-phase-configuration>, and filter-chains, which is a list
+of <opensmtpd-filter-configuration> and <opensmtpd-filter-phase-configuration>.  An example of what this
+might return is:
+
+#+BEGIN_SRC scheme
+(list (list (opensmtpd-filter))
+      (list (opensmtpd-filter-phase-configuration))
+      (list (opensmtpd-filter) ; this list is a filter-chain
+            (opensmtpd-filter-phase-configuration))
+      (list (opensmtpd-filter-phase-configuration) ; this list is also a filter chain
+            (opensmtpd-filter)
+            (opensmtpd-filter)))
+#+END_SRC
+
+These are some example bits of code that I can test my resulting code on.
+
+All unique filters of <opensmtpd-filter-configuration> and <opensmtpd-filter-phase-configuration>.  4 of
+them.  One listen-on has no filters.
+#+BEGIN_SRC scheme
+(let ([interface "lo"]
+      [filter-dkimsign (opensmtpd-filter
+                        (name "dkimsign")
+                        (exec #t)
+                        (proc (string-append "/path/to/dkimsign  -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                                             "/path/to/dkimsign-key user nobody group nobody")))])
+  (opensmtpd-configuration
+   (listen-on-socket
+    (opensmtpd-listen-on-socket-configuration-configuration
+     (filters (list (opensmtpd-filter
+                     (name "rspamd")
+                     (proc "rspamd"))))))
+   (listen-ons
+    (list
+     (opensmtpd-listen-on-configuration
+      (interface interface)
+      (filters (list (opensmtpd-filter-phase-configuration
+                      (name "noFRDNS")
+                      (phase "commit")
+                      (options (list (opensmtpd-option-configuration
+                                         (option "fcrdns")
+                                         (not #t))))
+                      (decision "disconnect")
+                      (message "No FCRDNS")))))
+     ;; this lets local users logged into the system via ssh send email
+     (opensmtpd-listen-on
+      (interface interface)
+      (port 27)
+      (filters (list filter-dkimsign)))
+     (opensmtpd-listen-on-configuration
+      (port 29)
+      (interface interface))
+     (opensmtpd-listen-on-configuration
+      (interface interface)
+      (filters (list (opensmtpd-filter
+                      (name "rspamd")
+                      (proc "rspamd")
+                      (exec #t)))))))))
+#+END_SRC
+
+4 unique filters.  One of the filters is a filter chain.
+#+BEGIN_SRC scheme
+(let ([interface "lo"]
+      [filter-dkimsign (opensmtpd-filter
+                        (name "dkimsign")
+                        (exec #t)
+                        (proc (string-append "/path/to/dkimsign  -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                                             "/path/to/dkimsign-key user nobody group nobody")))])
+  (opensmtpd-configuration
+   (listen-on-socket
+    (opensmtpd-listen-on-socket-configuration-configuration
+     (filters (list (opensmtpd-filter
+                     (name "spamassassain")
+                     (proc "spamassassain"))
+                   (opensmtpd-filter-phase-configuration
+                      (name "rdns")
+                      (phase "data")
+                      (options (list
+                                   (opensmtpd-option-configuration
+                                    (option "rdns")
+                                    (not #t))))
+                      (decision "reject")
+                      (message "No RDNS"))
+                    (opensmtpd-filter
+                     (name "block")
+                     (proc "block"))
+                    (opensmtpd-filter-phase-configuration
+                     (name "auth")
+                     (phase "commit")
+                     (options (list
+                                  (opensmtpd-option-configuration
+                                   (option "auth")
+                                   (regex #t)
+                                   (not #t)
+                                   (table (opensmtpd-table-configuration
+                                           (name "auth-table")
+                                           (data (list ".*@gmail.com"
+                                                         ".*@dismail.de")))))))
+                     (decision "junk"))))))
+   (listen-ons
+    (list
+     (opensmtpd-listen-on-configuration
+      (interface interface)
+      (filters (list (opensmtpd-filter-phase-configuration
+                      (name "noFRDNS")
+                      (phase "commit")
+                      (options (list (opensmtpd-option-configuration
+                                         (option "fcrdns")
+                                         (not #t))))
+                      (decision "disconnect")
+                      (message "No FCRDNS")))))
+     ;; this lets local users logged into the system via ssh send email
+     (opensmtpd-listen-on-configuration
+      (interface interface)
+      (port 27)
+      (filters (list filter-dkimsign)))
+     (opensmtpd-listen-on-configuration
+      (port 29)
+      (interface interface))
+     (opensmtpd-listen-on-configuration
+      (interface interface)
+      (filters (list (opensmtpd-filter
+                      (name "rspamd")
+                      (proc "rspamd")
+                      (exec #t)))))))))
+#+END_SRC
+
+No filters at all.
+#+BEGIN_SRC scheme
+(get-opensmtpd-filters (opensmtpd-configuration)) ; no filters at all.
+#+END_SRC
+
+This one prints rspamd twice!  The get-opensmtpd-filters procedure returns a
+duplicate filter.  While get-opensmtpd-filters does return a duplicate filter.
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (listen-on-socket
+  (opensmtpd-listen-on-configuration-socket-configuration
+   (filters
+    (list (opensmtpd-filter
+           (name "rando")
+           (proc "rando"))))))
+ (listen-ons
+  (list
+   (opensmtpd-listen-on-configuration
+    (port 25)
+    (filters (list (opensmtpd-filter-phase-configuration
+                    (name "noFRDNS")
+                    (phase "commit")
+                    (options (list (opensmtpd-option-configuration
+                                       (option "fcrdns")
+                                       (not #t))))
+                    (decision "disconnect")
+                    (message "No FCRDNS"))
+                   (opensmtpd-filter
+                    (name "rspamd")
+                    (proc "rspamd")))))
+   (opensmtpd-listen-on-configuration
+    (port 465)
+    (filters (list
+              (opensmtpd-filter
+               (name "rspamd")
+               (proc "rspamd"))
+              (opensmtpd-filter
+               (name "block")
+               (proc "block")))))
+   (opensmtpd-listen-on-configuration
+    (port 587))
+   (opensmtpd-listen-on-configuration
+    (port 999)
+    (filters (list
+              (opensmtpd-filter
+               (name "bogofilter")
+               (proc "bogofilter"))))))))
+#+END_SRC
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (listen-ons
+  (list
+   (opensmtpd-listen-on-configuration
+    (filters (list (opensmtpd-filter
+                    (name "bogofilter")
+                    (proc "bogofilter")))))
+   (opensmtpd-listen-on-configuration
+    (filters (list (opensmtpd-filter
+                    (name "noFRDNS")
+                    (proc "noFRDNS"))
+                   (opensmtpd-filter
+                    (name "rspamd")
+                    (proc "rspamd"))))))))
+#+END_SRC
+**** PROJ by which method should I turn the filters in =<opensmtpd-configuration>= into strings? [1/3]
+
+in (opensmtpd-configuration->mixed-text-file ) do either
+
+1. one line of code. faster, but violates the convention set by the other lines
+   of code around it.
+    #+BEGIN_SRC scheme
+   ;; write out all the filters
+   (opensmtpd-filters->string (get-opensmtpd-filters record))
+    #+END_SRC
+
+    This task in done: [[*(opensmtpd-filters->string (get-opensmtpd-filters record))][(opensmtpd-filters->string (get-opensmtpd-filters record))]]
+2. two lines of code. slower, but follows the convention set by the other lines
+   of code around it.
+    #+BEGIN_SRC scheme
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-filter-phase->string)
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
+    #+END_SRC
+
+***** DONE (opensmtpd-filters->string (get-opensmtpd-filters record))
+
+Have one procedure that prints out all filters.
+
+ #+BEGIN_SRC scheme
+;; write out all the filters
+(opensmtpd-filters->string (get-opensmtpd-filters record))
+ #+END_SRC
+
+***** PROJ 4 procedures: get-filter-and-filter-phases, filter-and-filter-phases->string, get-filter-chains, filter-chains->string
+
+The bonus with this method is that I can add these two lines in
+opensmtpd-configuration->mixed-text-file and keep a consistent coding framework:
+
+#+BEGIN_SRC scheme
+;; write out all the filters and filter-phases
+(opensmtpd-configuration-fieldname->string record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-filter-phase->string)
+;; write out all the filter chains
+(opensmtpd-configuration-fieldname->string record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
+#+END_SRC
+**** DONE fix the sanitize procedure for =<opensmtpd-filter-phase-configuration>= fieldnames 'phase-name', 'decision', etc. [5/5]
+***** DONE sanitize =<opensmtpd-filter-phase-configuration>= so that fieldname 'decision' option "reject" and "disconnect" requires a 'message'.
+:LOGBOOK:
+CLOCK: [2022-04-01 Fri 22:45]--[2022-04-02 Sat 04:13] =>  5:28
+:END:
+
+This message must be RFC compliant.  The message must start with 4xx or 5xx
+status code.
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration
+ (filters (list
+           (opensmtpd-filter-phase-configuration
+            (name "junk")
+            (phase "connect")
+            (decision "junk")
+            (options
+             (list
+              (opensmtpd-option-configuration
+               (option "rdns")))))
+           (opensmtpd-filter-phase-configuration
+            (name "src")
+            (phase "connect")
+            (options
+             (list
+              (opensmtpd-option-configuration
+               (option "src")
+               (data (opensmtpd-table-configuration
+                       (name "src-table")
+                       (data (list "cat" "hat")))))))
+            (decision "reject")))))
+#+END_SRC
+
+#+RESULTS:
+
+#+BEGIN_EXAMPLE
+<opensmtpd-filter-phase-configuration> fieldname: 'decision' options "disconnect" and "reject" require fieldname 'message'
+to have a string.
+ice-9/boot-9.scm:1685:16: In procedure raise-exception:
+Throw to key `bad!' with args `(#<<opensmtpd-filter-phase-configuration> name: "src" phase: "connect" options: (#<<opensmtpd-option-configuration> option: "src" not: #f regex: #f table: #<<opensmtpd-table-configuration> name: "src-table" file-db: #f values: ("cat" "hat") type: #<procedure 435f560 at <unknown port>:5894:22 (x)>>>) decision: "reject" message: #f value: #f>)'.
+
+Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
+#+END_EXAMPLE
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration
+ (filters (list
+           (opensmtpd-filter-phase-configuration
+            (name "junk")
+            (phase "connect")
+            (decision "junk")
+            (options
+             (list
+              (opensmtpd-option-configuration
+               (option "rdns")))))
+           (opensmtpd-filter-phase-configuration
+            (name "src")
+            (phase "connect")
+            (options
+             (list
+              (opensmtpd-option-configuration
+               (option "src")
+               (data (opensmtpd-table-configuration
+                       (name "src-table")
+                       (data (list "cat" "hat")))))))
+            (decision "reject")
+            (message "322 Hello")))))
+<opensmtpd-filter-phase-configuration> fieldname: 'decision' options
+"disconnect" and "reject" require fieldname 'message' to have a string.
+The 'message' string must be RFC commpliant, which means that the string
+must begin with a 4xx or 5xx status code.
+ice-9/boot-9.scm:1685:16: In procedure raise-exception:
+Throw to key `bad!' with args `(#<<opensmtpd-filter-phase-configuration> name: "src" phase: "connect" options: (#<<opensmtpd-option-configuration> option: "src" not: #f regex: #f data: #<<opensmtpd-table-configuration> name: "src-table" file-db: #f data: ("cat" "hat") type: #<procedure 44d2140 at <unknown port>:1153:21 (x)>>>) decision: "reject" message: "322 Hello" value: #f>)'.
+
+Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
+#+END_SRC
+***** DONE sanitize =<opensmtpd-filter-phase-configuration>= so that fieldname 'decision' option "rewrite" requires a 'value'.
+:LOGBOOK:
+CLOCK: [2022-04-01 Fri 22:45]--[2022-04-02 Sat 04:13] =>  5:28
+:END:
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration
+ (filters
+  (list
+   (opensmtpd-filter-phase-configuration
+    (name "noFRDNS")
+    (phase "commit")
+    (options (list (opensmtpd-option-configuration
+                    (option "fcrdns")
+                    (not #t))))
+    (value #f)
+    (decision "rewrite")) ;; there needs to be a value here.  rewrite requires a value!
+   )))
+$12 = #<<opensmtpd-listen-on-configuration> interface: "lo" family: #f auth: #f auth-optional: #f filters: (#<<opensmtpd-filter-phase-configuration> name: "noFRDNS" phase: "commit" options: (#<<opensmtpd-option-configuration> option: "fcrdns" not: #t regex: #f data: #f>) decision: "rewrite" message: #f value: 343>) hostname: #f hostnames: #f mask-src: #f disable-dsn: #f pki: #f port: #f proxy-v2: #f received-auth: #f secure-connection: #f tag: #f>
+scheme@(opensmtpd-records) [10]> (opensmtpd-listen-on-configuration
+ (filters
+  (list
+   (opensmtpd-filter-phase-configuration
+    (name "noFRDNS")
+    (phase "commit")
+    (options (list (opensmtpd-option-configuration
+                    (option "fcrdns")
+                    (not #t))))
+    (decision "rewrite")) ;; there needs to be a value here.  rewrite requires a value!
+   )))
+<opensmtpd-filter-phase-configuration> fieldname: 'decision' option
+"rewrite" requires fieldname 'value'
+to have a number.
+ice-9/boot-9.scm:1685:16: In procedure raise-exception:
+Throw to key `bad!' with args `(#<<opensmtpd-filter-phase-configuration> name: "noFRDNS" phase: "commit" options: (#<<opensmtpd-option-configuration> option: "fcrdns" not: #t regex: #f data: #f>) decision: "rewrite" message: #f value: #f>)'.
+
+Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
+#+END_SRC
+
+***** DONE sanitize =<opensmtpd-filter-phase-configuration>= so that fieldname 'decision' option "junk" and "bypass" have no message or value
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration
+ (filters
+  (list
+   (opensmtpd-filter-phase-configuration
+    (name "noFRDNS")
+    (phase "commit")
+    (options (list (opensmtpd-option-configuration
+                    (option "fcrdns")
+                    )))
+    (decision "junk")
+    (message "This is not a good email."))))) ; there should NOT be a message here!  junk has no message.
+#+END_SRC
+***** DONE sanitize the options too.  rdns requires a table for instance:
+
+#+BEGIN_EXAMPLE
+At each phase, various conditions may be matched.  The fcrdns, rdns, and src data are
+available in all phases, but other data must have been already submitted before they are
+available.
+
+      fcrdns                   forward-confirmed reverse DNS is valid
+      rdns                     session has a reverse DNS
+      rdns <table>             session has a reverse DNS in table
+      src <table>              source address is in table
+      helo <table>             helo name is in table
+      auth                     session is authenticated
+      auth <table>             session username is in table
+      mail-from <table>        sender address is in table
+      rcpt-to <table>          recipient address is in table
+#+END_EXAMPLE
+***** DONE sanitize <opensmtpd-filter-phase-configuration> make sure that 'junking happens before phase 'committed'.
+#+BEGIN_EXAMPLE
+     Descisions can be taken at any phase, though junking can only happen before a message is committed.
+#+END_EXAMPLE
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration
+ (filters
+  (list
+   (opensmtpd-filter-phase-configuration
+    (name "junk-after-commit")
+    (phase "commit")
+    (options (list (opensmtpd-option-configuration
+                    (option "fcrdns")
+                    )))
+    (decision "junk")))))
+#+END_SRC
+*** PROJ make fieldnames that need a table accept a value of table [3/4]
+**** DONE opensmtpd-action-local-delivery-configuration [3/3]
+***** DONE alias =<alias>= [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 03:53]
+:END:
+****** DONE change the sanitize portion of the fieldname alias in the <opensmtpd-action-local-delivery-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-action-local-delivery-configuration
+ (alias
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data (list "gnu-hurd.com" "gnucode.me")))))
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-action-local-delivery-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-action-local-delivery-configuration->string)
+ (opensmtpd-action-local-delivery-configuration
+  (alias
+   (opensmtpd-table-configuration
+    (name "My-table")
+    (data (list "gnu-hurd.com" "gnucode.me"))))))
+#+END_SRC
+
+***** DONE userbase =<users>= [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 03:53]
+:END:
+
+****** DONE change the sanitize portion of the fieldname userbase in the <opensmtpd-action-local-delivery-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+(opensmtpd-action-local-delivery-configuration
+ (userbase
+  (opensmtpd-table-configuration
+   (name "this")
+   (data (list "job" "done")))))
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-action-local-delivery-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-action-local-delivery-configuration->string)
+ (opensmtpd-action-local-delivery-configuration
+  (userbase
+   (opensmtpd-table-configuration
+    (name "this")
+    (data (list "job" "done"))))))
+#+END_SRC
+
+***** DONE virtual [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 03:53]
+:END:
+****** DONE change the sanitize portion of the fieldname virtual in the <opensmtpd-action-local-delivery-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+(opensmtpd-action-local-delivery-configuration
+ (virtual
+  (opensmtpd-table-configuration
+   (name "this")
+   (data (list "job" "done")))))
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-action-local-delivery-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-action-local-delivery-configuration->string)
+ (opensmtpd-action-local-delivery-configuration
+  (virtual
+   (opensmtpd-table-configuration
+    (name "this")
+    (data (list "job" "done"))))))
+
+#+END_SRC
+
+**** DONE opensmtpd-relay-configuration  [4/4]
+***** DONE helo-src <helos>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:00]
+:END:
+***** DONE domain =<domains>= [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:00]
+:END:
+
+****** DONE change the sanitize portion of the fieldname domain in the <opensmtpd-action-relay-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-action-relay-configuration
+                           (domain
+                            (opensmtpd-table-configuration
+                             (name "this")
+                             (data (list "gnucode.me" "gnu-hurd.com")))))
+
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-action-relay-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-action-relay-configuration->string)
+                          (opensmtpd-action-relay-configuration
+                           (domain
+                            (opensmtpd-table-configuration
+                             (name "this")
+                             (data (list "gnucode.me" "gnu-hurd.com"))))))
+
+
+#+END_SRC
+
+***** DONE auth =<credentials>= [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:00]
+:END:
+****** DONE change the sanitize portion of the fieldname =<auth>= in the <opensmtpd-action-relay-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-action-relay-configuration
+                           (auth
+                            (opensmtpd-table-configuration
+                             (name "this")
+                             (data (list "gnucode.me" "gnu-hurd.com")))))
+
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-action-relay-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-action-relay-configuration->string)
+                          (opensmtpd-action-relay-configuration
+                           (auth
+                            (opensmtpd-table-configuration
+                             (name "this")
+                             (data (list "gnucode.me" "gnu-hurd.com"))))))
+
+
+#+END_SRC
+
+***** DONE src srcaddress | <IP addresses>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:01]
+:END:
+****** DONE change the sanitize portion of the fieldname =<auth>= in the <opensmtpd-action-relay-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-action-relay-configuration
+                           (src
+                            (opensmtpd-table-configuration
+                             (name "this")
+                             (data (list "gnucode.me" "gnu-hurd.com")))))
+
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-action-relay-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-action-relay-configuration->string)
+                          (opensmtpd-action-relay-configuration
+                           (src
+                            (opensmtpd-table-configuration
+                             (name "this")
+                             (data (list "gnucode.me" "gnu-hurd.com"))))))
+
+
+#+END_SRC
+
+Use the string scraddress or list table <IP addresses> for the source IP address.
+**** DONE opensmtpd-listen-on-configuration [3/3]
+***** DONE auth =<credentials>= [3/3]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:01]
+:END:
+****** DONE change the sanitize portion of the fieldname 'auth' in the <opensmtpd-listen-on-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (auth
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '(("joshua" . "$some$Long$EncrytpedPassword"))))))
+#+END_SRC
+
+#+RESULTS:
+****** DONE change relevant portions in opensmtpd-listen-on-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-listen-on-configuration->string)
+ (opensmtpd-listen-on-configuration
+  (auth
+   (opensmtpd-table-configuration
+    (name "credentials")
+    (data '(("joshua" . "$someLongEncrytpedPassword")))))))
+#+END_SRC
+
+****** DONE sanitize the =<opensmtpd-table-configuration>= so that it can only be an opensmtpd-table-configuration, whose fieldname values are an assoc-list
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration (auth (opensmtpd-table-configuration (name "the") (data (list "the" "cat")))))
+#+END_SRC
+
+#+RESULTS: =<opensmtpd-listen-on-configuration>= fieldname: 'auth' is of type boolean, or an =<opensmtpd-table-configuration>= record whose fieldname 'values' are an assoc-list.
+
+***** DONE auth-optional =<credentials>= [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:01]
+:END:
+****** DONE change the sanitize portion of the fieldname 'auth-optional' in the <opensmtpd-listen-on-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (auth
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '(("joshua" . "$some$Long$EncrytpedPassword"))))))
+#+END_SRC
+
+#+RESULTS:
+
+AND the below code will correctly result in an error!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (auth
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '("joshua" "$some$Long$EncrytpedPassword")))))
+#+END_SRC
+
+#+RESULTS:
+: =<opensmtpd-listen-on-configuration>= fieldname: 'auth' is of type boolean, or an =<opensmtpd-table-configuration>= record whose fieldname 'values' are an assoc-list
+: (eg: (opensmtpd-table-configuration (name "table") (data '("joshua" . "$encrypted$password")))).
+
+****** DONE change relevant portions in opensmtpd-listen-on-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-listen-on-configuration->string)
+ (opensmtpd-listen-on-configuration
+  (auth
+   (opensmtpd-table-configuration
+    (name "credentials")
+    (data '(("joshua" . "$someLongEncrytpedPassword")))))))
+#+END_SRC
+
+***** DONE hostnames =<hostnames>= [2/2]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:01]
+:END:
+****** DONE change the sanitize portion of the fieldname 'hostnames' in the <opensmtpd-listen-on-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (hostnames
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '(("joshua" . "$some$Long$EncrytpedPassword"))))))
+#+END_SRC
+
+#+RESULTS:
+
+AND the below code will correctly result in an error!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (hostnames
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '("joshua" "$some$Long$EncrytpedPassword")))))
+#+END_SRC
+
+#+RESULTS:
+: =<opensmtpd-listen-on-configuration>= fieldname: 'hostname' is of type boolean, or an =<opensmtpd-table-configuration>= record whose fieldname 'values' are an assoc-list
+: (eg: (opensmtpd-table-configuration (name "table") (data '("joshua" . "$encrypted$password")))).
+
+****** DONE change relevant portions in opensmtpd-listen-on-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-listen-on-configuration->string)
+ (opensmtpd-listen-on-configuration
+  (hostnames
+   (opensmtpd-table-configuration
+    (name "credentials")
+    (data '(("joshua" . "$someLongEncrytpedPassword")))))))
+#+END_SRC
+
+**** TODO opensmtpd-match [20/24]
+******* NO list approach
+Guix probably won't like the list approach.
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (for
+    (list 'not "for domain regex"
+          (opensmtpd-table-configuration
+           (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (for
+    (list "! for domain"
+          (opensmtpd-table-configuration
+           (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+******* opensmtpd-options-configuration approach  I like this one quite a bit.
+
+This method is a little bit more verbose.  Well I guess it's a lot
+more verbose.  But it's easier for me to properly parse what the user wants.
+
+I would sanitize the options in the opensmtpd-match-configuration-for,
+openmsmtpd-match-from, opensmtpd-match-configuration-auth, opensmtpd-match-configuration-helo,
+opensmtpd-match-configuration-mail-from, opensmtpd-match-configuration-rcpt-to fieldnames.
+********* for
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (for
+    (opensmtpd-options-configuration
+     (not #t)
+     (method "domain regex") ;; valid options for "for" are "domain" or "domain regex"
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+Do I want a regex fieldname?  Probably not.  It makes it more verbose...
+
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (for
+    (opensmtpd-options-configuration
+     (not #t)
+     (regex #t)
+     (method "domain") ;; valid options for "for" are "domain"
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+********* from
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (from
+    (opensmtpd-options-configuration
+     (not #t)
+     (method "rdns regex") ;;valid options for from are "auth" "auth regex", "mail-from" "mail-from regex",
+                           ;; "rdns", "rdns regex", "src", "src regex"
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+Do I want a regex fieldname?
+
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (from
+    (opensmtpd-options-configuration
+     (not #t)
+     (regex #t)
+     (method "rdns") ;;valid options for from are "auth", "mail-from", "rdns", "src"
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+********* auth
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (auth
+    (opensmtpd-options-configuration
+     (not #t)
+     (method "auth regex")
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+Do I want a regex fieldname?
+
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (auth
+    (opensmtpd-options-configuration
+     (not #t)
+     (regex #t)
+     (method "auth") ;; valid options for auth are "auth" or this method can be left blank.
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+
+********* mail-from
+#+BEGIN_SRC scheme
+  (openmstpd-match
+   (mail-from
+    (opensmtpd-options-configuration
+     (not #t)
+     (method "mail from")
+     (opensmtpd-table-configuration
+      (data (list "gnucode.me" "gnu-hurd.com"))))))
+#+END_SRC
+****** I tweak opensmtpd-match record and add a opensmtpd-options
+
+#+BEGIN_SRC scheme
+  (opensmtpd-match-configuration
+   (name "action-name")
+   (options
+    (list
+     (opensmtpd-options-configuration
+      (method "for domain regex")))
+    ))
+#+END_SRC
+
+****** PROJ many of these options are not completely sanitized.
+
+For example: "for domain" requires a domain | <domain> BUT this record, which
+does not have a domain gives no errors:
+
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration
+ (for (opensmtpd-option-configuration
+       (option "for domain")))
+ (action (opensmtpd-action-local-delivery-configuration
+          (name "local") )))
+#+END_SRC
+
+And there are a ton of other examples of this.
+****** DONE for domain <domains>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:17]
+:END:
+
+The datastructures work:
+
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration
+ (name "local")
+ (for (opensmtpd-option-configuration
+       (option "for domain")
+       (value (opensmtpd-table-configuration
+               (name "this")
+               (data (list "helo" "hello"))))))
+ (action (opensmtpd-action-local-delivery-configuration)))
+#+END_SRC
+
+#Results
+: $4 = #<<opensmtpd-match-configuration> name: "local" action: #<<opensmtpd-action-local-delivery-configuration> method: "mbox" alias: #f ttl: #f user: #f userbase: #f virtual: #f wrapper: #f> for: #<<opensmtpd-option-configuration> option: "for domain" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "this" file-db: #f values: ("helo" "hello") type: #<procedure 2b33238 at <unknown port>:148:97 (x)>>> from: #f auth: #f helo: #f mail-from: #f rcpt-to: #f tag: #f tls: #f>
+
+****** DONE for domain regexp <domains>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:19]
+:END:
+
+the datastructure works
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration
+ (name "local")
+ (for (opensmtpd-option-configuration
+       (regex #t)
+       (option "for domain")
+       (value (opensmtpd-table-configuration
+               (name "this")
+               (data (list "helo" "hello"))))))
+ (action (opensmtpd-action-local-delivery-configuration)))
+#+END_SRC
+
+#Results
+: $4 = #<<opensmtpd-match-configuration> name: "local" action: #<<opensmtpd-action-local-delivery-configuration> method: "mbox" alias: #f ttl: #f user: #f userbase: #f virtual: #f wrapper: #f> for: #<<opensmtpd-option-configuration> option: "for domain" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "this" file-db: #f values: ("helo" "hello") type: #<procedure 2b33238 at <unknown port>:148:97 (x)>>> from: #f auth: #f helo: #f mail-from: #f rcpt-to: #f tag: #f tls: #f>
+
+****** DONE make opensmtpd-match-configuration->string work print for rcpt the appropriate match lines if some values now accept <opensmtpd-table-configuration>
+
+Seems to work:
+
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration->string (opensmtpd-match-configuration
+ (name "local")
+ (for (opensmtpd-option-configuration
+       (regex #t)
+       (option "for domain")
+       (value (opensmtpd-table-configuration
+               (name "this")
+               (data (list "helo" "hello"))))))
+ (action (opensmtpd-action-local-delivery-configuration))))
+$6 = "match for domain regex =<this>= action \"local\" \n"
+#+END_SRC
+
+also seems to work
+
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration->string (opensmtpd-match-configuration
+ (name "local")
+ (for (opensmtpd-option-configuration
+       (option "for domain")
+       (value (opensmtpd-table-configuration
+               (name "this")
+               (data (list "helo" "hello"))))))
+ (action (opensmtpd-action-local-delivery-configuration))))
+$7 = "match for domain =<this>= action \"local\" \n"
+#+END_SRC
+****** DONE for rcpt <receipt>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:19]
+:END:
+****** DONE for rcpt regexp <recepit>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:19]
+:END:
+****** DONE from auth user | <user>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:19]
+:END:
+
+#+BEGIN_SRC scheme
+(opensmtpd-option-configuration
+       (regex #t)
+       (option "from auth")
+       (value (opensmtpd-table-configuration
+               (name "this")
+               (data (list "helo" "hello")))))
+$8 = #<<opensmtpd-option-configuration> option: "from auth" not: #f regex: #t value: #<<opensmtpd-table-configuration> name: "this" file-db: #f values: ("helo" "hello") type: #<procedure 2bfa848 at <unknown port>:224:14 (x)>>>
+
+#+END_SRC
+****** DONE from auth regex user | <user>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:20]
+:END:
+****** DONE make sure opensmtpd-option-configuration->string works for from auth if they use <opensmtpd-table-configuration>
+
+#+BEGIN_SRC scheme
+(opensmtpd-option-configuration->string
+ (opensmtpd-option-configuration
+  (regex #t)
+  (option "from auth")
+  (value (opensmtpd-table-configuration
+          (name "this")
+          (data (list "helo" "hello"))))))
+$10 = "from auth regex =<this>= "
+#+END_SRC
+****** DONE from mail-from sender | <sender>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:20]
+:END:
+****** DONE from mail-from regexp <sender>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:20]
+:END:
+****** DONE from rdns <hostname>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:20]
+:END:
+****** DONE from rdns regex <hostname>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:20]
+:END:
+****** DONE from src <address>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:21]
+:END:
+****** DONE from src regex <address>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:21]
+:END:
+****** TODO do some more sanitizing of these last couple of options
+There may be some way to specify invalid data.  For example:
+
+tls does not support regex, not, or value fields.  The below code should be an error.
+#+BEGIN_SRC scheme
+ (display (opensmtpd-match-configuration->string (opensmtpd-match-configuration
+ (tls (opensmtpd-option-configuration
+        (option "tls") ;; this should be auth!!! NOT "helo"
+        (regex #t)
+        (not #t)
+        (value (opensmtpd-table-configuration  (name "mytable")
+                                 (data (list "cat" "kitten"))))))
+ (from (opensmtpd-option-configuration (option "from rdns")
+                                             (value (opensmtpd-table-configuration (name "table")
+                                                                     (data (list "cat" "hat"))))))
+ (action (opensmtpd-action-local-delivery-configuration
+          (name "matches"))))))
+match from rdns <table> ! tls regex <mytable> action "matches"
+#+END_SRC
+
+****** DONE auth <username>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:21]
+:END:
+
+Well I need to fix this bug.  Basically, I can make an
+<opensmtpd-option-configuration> with a table of values for 'option' "auth". And
+I can print that table with (opensmtpd-option-configuration->string)...That works
+fine...
+
+But if I put that same record into an =<opensmtpd-match-configuration>= ...for some reason that
+'auth' table is not being printed.
+
+#+BEGIN_SRC scheme
+(opensmtpd-option-configuration
+                                 (option "auth")
+                                 (value (opensmtpd-table-configuration (name "mytable")
+                                                         (data (list "cat" "hat")))))
+$20 = #<<opensmtpd-option-configuration> option: "auth" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "mytable" file-db: #f values: ("cat" "hat") type: #<procedure 1ee6ce8 at <unknown port>:860:40 (x)>>>
+scheme@(opensmtpd-records) [4]> (opensmtpd-option-configuration->string $20)
+$21 = "auth =<mytable>= "
+scheme@(opensmtpd-records) [4]> (opensmtpd-match (name "matches")
+                                                 (auth (opensmtpd-option-configuration
+                                                        (option "auth")
+                                                        (value (opensmtpd-table-configuration  (name "mytable")
+                                                                                 (data (list "cat" "kitten"))))))
+                                             (from (opensmtpd-option-configuration (option "from rdns")
+                                                                                  (value (opensmtpd-table-configuration (name "table")
+                                                                                                          (data (list "cat" "hat"))))))
+                                             (action (opensmtpd-action-local-delivery-configuration)))
+$22 = #<<opensmtpd-match-configuration> name: "matches" action: #<<opensmtpd-action-local-delivery-configuration> method: "mbox" alias: #f ttl: #f user: #f userbase: #f virtual: #f wrapper: #f> for: #f from: #<<opensmtpd-option-configuration> option: "from rdns" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "table" file-db: #f values: ("cat" "hat") type: #<procedure 30bac20 at <unknown port>:876:89 (x)>>> auth: #<<opensmtpd-option-configuration> option: "auth" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "mytable" file-db: #f values: ("cat" "kitten") type: #<procedure 30baa80 at <unknown port>:873:63 (x)>>> helo: #f mail-from: #f rcpt-to: #f tag: #f tls: #f>
+scheme@(opensmtpd-records) [5]> (opensmtpd-match-configuration->string $22)
+$23 = "match from rdns =<table>= auth action \"matches\" \n"  ;; THERE IS SUPPOSED TO BE a "auth <mytable>" here
+scheme@(opensmtpd-records) [5]>
+#+END_SRC
+****** TODO [!] auth
+****** TODO auth regex <username>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:21]
+:END:
+
+This does NOT show the regex for the auth option.  or the table <mytable> why?
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration
+ (auth (opensmtpd-option-configuration
+        (option "auth") ;; this should be auth!!! NOT "helo"
+        (regex #t)
+        (value (opensmtpd-table-configuration  (name "mytable")
+                                 (data (list "cat" "kitten"))))))
+ (from (opensmtpd-option-configuration (option "from rdns")
+                                             (value (opensmtpd-table-configuration (name "table")
+                                                                     (data (list "cat" "hat"))))))
+ (action (opensmtpd-action-local-delivery-configuration
+          (name "matches"))))
+$9 = #<<opensmtpd-match-configuration> action: #<<opensmtpd-action-local-delivery-configuration> name: "matches" method: "mbox" alias: #f ttl: #f user: #f userbase: #f virtual: #f wrapper: #f> for: #f from: #<<opensmtpd-option-configuration> option: "from rdns" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "table" file-db: #f values: ("cat" "hat") type: #<procedure 1fb5fc0 at <unknown port>:144:52 (x)>>> auth: #<<opensmtpd-option-configuration> option: "auth" not: #f regex: #t value: #<<opensmtpd-table-configuration> name: "mytable" file-db: #f values: ("cat" "kitten") type: #<procedure 1fb5c40 at <unknown port>:141:15 (x)>>> helo: #f mail-from: #f rcpt-to: #f tag: #f tls: #f>
+scheme@(opensmtpd-records) [4]> (display (opensmtpd-match-configuration->string $9))
+match from rdns <table> auth action "matches" ;; there should be a regex in there.
+#+END_SRC
+****** DONE helo <helo-name>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:21]
+:END:
+#+BEGIN_SRC scheme
+(opensmtpd-match-configuration
+ (helo (opensmtpd-option-configuration
+        (option "helo") ;; this should be auth!!! NOT "helo"
+        (regex #t)
+        (value (opensmtpd-table-configuration  (name "mytable")
+                                 (data (list "cat" "kitten"))))))
+ (from (opensmtpd-option-configuration (option "from rdns")
+                                             (value (opensmtpd-table-configuration (name "table")
+                                                                     (data (list "cat" "hat"))))))
+ (action (opensmtpd-action-local-delivery-configuration
+          (name "matches"))))
+$10 = #<<opensmtpd-match-configuration> action: #<<opensmtpd-action-local-delivery-configuration> name: "matches" method: "mbox" alias: #f ttl: #f user: #f userbase: #f virtual: #f wrapper: #f> for: #f from: #<<opensmtpd-option-configuration> option: "from rdns" not: #f regex: #f value: #<<opensmtpd-table-configuration> name: "table" file-db: #f values: ("cat" "hat") type: #<procedure 24d6840 at <unknown port>:252:52 (x)>>> auth: #f helo: #<<opensmtpd-option-configuration> option: "helo" not: #f regex: #t value: #<<opensmtpd-table-configuration> name: "mytable" file-db: #f values: ("cat" "kitten") type: #<procedure 24d64c0 at <unknown port>:249:15 (x)>>> mail-from: #f rcpt-to: #f tag: #f tls: #f>
+scheme@(opensmtpd-records) [5]> (opensmtpd-match-configuration->string $10)
+$11 = "match from rdns <table> helo regex <mytable> action \"matches\" \n"
+#+END_SRC
+****** DONE mail-from <sender>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:22]
+:END:
+#+BEGIN_SRC scheme
+ (display (opensmtpd-match-configuration->string (opensmtpd-match-configuration
+ (mail-from (opensmtpd-option-configuration
+        (option "mail-from") ;; this should be auth!!! NOT "helo"
+        (regex #t)
+        (not #t)
+        (value (opensmtpd-table-configuration  (name "mytable")
+                                 (data (list "cat" "kitten"))))))
+ (from (opensmtpd-option-configuration (option "from rdns")
+                                             (value (opensmtpd-table-configuration (name "table")
+                                                                     (data (list "cat" "hat"))))))
+ (action (opensmtpd-action-local-delivery-configuration
+          (name "matches"))))))
+match from rdns <table> ! mail-from regex <mytable> action "matches"
+#+END_SRC
+****** DONE mail-from regex <sender>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:22]
+:END:
+#+BEGIN_SRC scheme
+ (display (opensmtpd-match-configuration->string (opensmtpd-match-configuration
+ (mail-from (opensmtpd-option-configuration
+        (option "mail-from") ;; this should be auth!!! NOT "helo"
+        (regex #t)
+        (not #t)
+        (value (opensmtpd-table-configuration  (name "mytable")
+                                 (data (list "cat" "kitten"))))))
+ (from (opensmtpd-option-configuration (option "from rdns")
+                                             (value (opensmtpd-table-configuration (name "table")
+                                                                     (data (list "cat" "hat"))))))
+ (action (opensmtpd-action-local-delivery-configuration
+          (name "matches"))))))
+match from rdns <table> ! mail-from regex <mytable> action "matches"
+#+END_SRC
+****** DONE rcpt-to <receipient>
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:22]
+:END:
+****** DONE rcpt-to regex <receipient>
+:LOGBOOK:
+- State "TODO"       from "TODO"       [2021-11-02 Tue 04:23]
+:END:
+
+*** PROJ sanitize the =<opensmtpd-option-configuration>= records in =<opensmtpd-filter-phase>= & =<opensmtpd-match-configuration>=
+**** PROJ testing the sanitize-list-of-options-for-match-configuration-assoc precodure [5/5]
+***** DONE make sure each option is unique (no duplicate "for"s).
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (matches (list
+           (opensmtpd-match-configuration
+            (options (list
+                      (opensmtpd-option-configuration
+                       (option "for any"))
+                      (opensmtpd-option-configuration
+                       (option "for local"))))
+            (action
+             (opensmtpd-action-relay-configuration
+              (name "relay")))))))
+#+END_SRC
+***** DONE make sure there is no duplicate from's
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (matches (list
+           (opensmtpd-match-configuration
+            (options (list
+                      (opensmtpd-option-configuration
+                       (option "from any"))
+                      (opensmtpd-option-configuration
+                       (option "from auth"))))
+            (action
+             (opensmtpd-action-relay-configuration
+              (name "relay")))))))
+#+END_SRC
+***** DONE for any data and regex must be false
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (matches (list
+           (opensmtpd-match-configuration
+            (options (list
+                      (opensmtpd-option-configuration
+                       (option "for any")
+                       (regex #t))))
+            (action
+             (opensmtpd-action-relay-configuration
+              (name "relay")))))))
+#+END_SRC
+***** DONE 'rcpt-to' must have data
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (matches (list
+           (opensmtpd-match-configuration
+            (options (list
+                      (opensmtpd-option-configuration
+                       (option "rcpt-to"))))
+            (action
+             (opensmtpd-action-relay-configuration
+              (name "relay")))))))
+#+END_SRC
+***** DONE 'tls' cannot have a 'data' or 'regex'
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (matches (list
+           (opensmtpd-match-configuration
+            (options (list
+                      (opensmtpd-option-configuration
+                       (option "tls")
+                       (data "hello")
+                       )))
+            (action
+             (opensmtpd-action-relay-configuration
+              (name "relay")))))))
+#+END_SRC
+*** TODO sanitize <opensmtpd-configuration> fieldname 'matches' so that no two unique actions have the same name
+I definitely should sanitize 'matches' a bit more.  For example, you could have two different
+actions, one for local delivery and one for remote, with the same name.  I
+should make sure that all unique actions have unique names.
+
+Here is an example of two actions that have the same name, but different ttl values:
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration
+ (matches
+  (list (opensmtpd-match-configuration
+         (action
+          (opensmtpd-action-local-delivery-configuration
+           (name "my-local-delivery")
+           (ttl "50m"))))               ; 50 minutes
+        (opensmtpd-match-configuration
+         (action
+          (opensmtpd-action-local-delivery-configuration
+           (name "my-local-delivery")
+           (ttl "50h"))))))) ; 50 hours
+#+END_SRC
+
+*** PROJ follow the style guide and style up my project [0/4]
+https://mumble.net/~campbell/scheme/style.txt
+
+:SchemeStyleGuide:
+#+BEGIN_SRC org
+Riastradh's Lisp Style Rules                            -*- outline -*-
+
+   Copyright (C) 2007--2011 Taylor R. Campbell
+
+   CC BY-NC-SA 3.0
+
+   This work is licensed under a Creative Commons
+   Attribution-NonCommercial-ShareAlike 3.0 Unported License:
+   <http://creativecommons.org/licenses/by-nc-sa/3.0/>.
+
+This is a guide to Lisp style, written by Taylor R. Campbell, to
+describe the standard rules of Lisp style as well as a set of more
+stringent rules for his own style.  This guide should be useful for
+Lisp in general, but there are [or will be in the final draft] parts
+that are focussed on or specific to Scheme or Common Lisp.
+
+This guide is written primarily as a collection of rules, with
+rationale for each rule.  (If a rule is missing rationale, please
+inform the author!)  Although a casual reader might go through and read
+the rules without the rationale, perhaps reasoning that reading of the
+rationale would require more time than is available, such a reader
+would derive little value from this guide.  In order to apply the rules
+meaningfully, their spirit must be understood; the letter of the rules
+serves only to hint at the spirit.  The rationale is just as important
+as the rules.
+
+There are many references in this document to `Emacs', `GNU Emacs',
+`Edwin', and so on.  In this document, `Emacs' means any of a class of
+editors related in design to a common ancestor, the EMACS editor macros
+written for TECO on ITS on the PDP-10 in the middle of the nineteen
+seventies.  All such editors -- or `all Emacsen', since `Emacsen' is
+the plural of `Emacs' -- have many traits in common, such as a very
+consistent set of key bindings, extensibility in Lisp, and so on.  `GNU
+Emacs' means the member of the class of editors collectively known as
+Emacsen that was written for the GNU Project in the middle of the
+nineteen eighties, and which is today probably the most popular Emacs.
+`Edwin' is MIT Scheme's Emacs, which is bundled as part of MIT Scheme,
+and not available separately.  There are other Emacsen as well, such as
+Hemlock and Climacs, but as the author of this document has little
+experience with Emacsen other than GNU Emacs and Edwin, there is little
+mention of other Emacsen.
+
+This guide is a work in progress.  To be written:
+
+- Indentation rules for various special operators.
+- Philosophical rambling concerning naming.
+- Rules for breaking lines.
+- Many more examples.
+- A more cohesive explanation of the author's principles for composing
+  programs, and their implications.
+- Rules for writing portable code.
+- Some thoughts concerning extensions to the lexical syntax.
+- Rules for writing or avoiding macros.
+- Some unfinished rationale.
+- More on documentation.
+- The `Dependencies' subsection of the `General Layout' section should
+  be put in a different section, the rest of which has yet to be
+  written, on organization of programs, module systems, and portable
+  code.
+
+Feedback is welcome; address any feedback by email to the host
+mumble.net's user `campbell', or by IRC to Riastradh in the #scheme
+channel on Freenode (irc.freenode.net).  Feedback includes reports of
+typos, questions, requests for clarification, and responses to the
+rationale, except in the case of round brackets versus square
+brackets, the argument surrounding which is supremely uninteresting
+and now not merely a dead horse but a rotting carcass buzzing with
+flies and being picked apart by vultures.
+
+As this document has grown, the line between standard Lisp rules and
+the author's own style has been blurred.  The author is considering
+merging of the partition, but has not yet decided on this with
+certainty.  Opinions on the subject are welcome -- is the partition
+still useful to keep the author's biases and idiosyncrasies out of the
+standard rules, or has the partition with its arbitrary nature only
+caused disorganization of the whole document?
+
+Unfortunately, this document is entirely unscientific.  It is at best a
+superstition or philosophy, but one that the author of this document
+has found to have improved his programs.  Furthermore, the author is
+somewhat skeptical of claims of scientific analyses of these matters:
+analyzing human behaviour, especially confined to the set of excellent
+programmers who often have strong opinions about their methods for
+building programs, is a very tricky task.
+
+,* Standard Rules
+
+These are the standard rules for formatting Lisp code; they are
+repeated here for completeness, although they are surely described
+elsewhere.  These are the rules implemented in Emacs Lisp modes, and
+auxiliary utilities such as Paredit.
+
+The rationale given here is merely the author's own speculation of the
+origin of these rules, and should be taken as nothing more than it.
+The reader shall, irrespective of the author's rationale, accept the
+rules as sent by the reader's favourite deity, or Cthulhu if no such
+deity strikes adequate fear into the heart of the reader.
+
+,** Parentheses
+
+,*** Terminology
+
+This guide avoids the term /parenthesis/ except in the general use of
+/parentheses/ or /parenthesized/, because the word's generally accepted
+definition, outside of the programming language, is a statement whose
+meaning is peripheral to the sentence in which it occurs, and *not* the
+typographical symbols used to delimit such statements.
+
+The balanced pair of typographical symbols that mark parentheses in
+English text are /round brackets/, i.e. ( and ).  There are several
+other balanced pairs of typographical symbols, such as /square
+brackets/ (commonly called simply `brackets' in programming circles),
+i.e. [ and ]; /curly braces/ (sometimes called simply `braces'), i.e. {
+and }; /angle brackets/ (sometimes `brokets' (for `broken brackets')),
+i.e. < and >.
+
+In any balanced pair of typographical symbols, the symbol that begins
+the region delimited by the symbols is called the /opening bracket/ or
+the /left bracket/, such as ( or [ or { or <.  The symbol that ends
+that region is called the /right bracket/ or the /closing bracket/,
+such as > or } or ] or ).
+
+,*** Spacing
+
+If any text precedes an opening bracket or follows a closing bracket,
+separate that text from that bracket with a space.  Conversely, leave
+no space after an opening bracket and before following text, or after
+preceding text and before a closing bracket.
+
+  Unacceptable:
+
+    (foo(bar baz)quux)
+    (foo ( bar baz ) quux)
+
+  Acceptable:
+
+    (foo (bar baz) quux)
+
+  Rationale:  This is the same spacing found in standard typography of
+  European text.  It is more aesthetically pleasing.
+
+,*** Line Separation
+
+Absolutely do *not* place closing brackets on their own lines.
+
+  Unacceptable:
+
+    (define (factorial x)
+      (if (< x 2)
+          1
+          (* x (factorial (- x 1
+                          )
+               )
+          )
+      )
+    )
+
+  Acceptable:
+
+    (define (factorial x)
+      (if (< x 2)
+          1
+          (* x (factorial (- x 1)))))
+
+  Rationale:  The parentheses grow lonely if their closing brackets are
+  all kept separated and segregated.
+
+,**** Exceptions to the Above Rule Concerning Line Separation
+
+Do not heed this section unless you know what you are doing.  Its title
+does *not* make the unacceptable example above acceptable.
+
+When commenting out fragments of expressions with line comments, it may
+be necessary to break a line before a sequence of closing brackets:
+
+  (define (foo bar)
+    (list (frob bar)
+          (zork bar)
+          ;; (zap bar)
+          ))
+
+This is acceptable, but there are other alternatives.  In Common Lisp,
+one can use the read-time optional syntax, `#+' or `#-', with a
+feature optional that is guaranteed to be false or true -- `#+(OR)'
+or `#-(AND)' --; for example,
+
+  (define (foo bar)
+    (list (frob bar)
+          (zork bar)
+          ,#+(or) (zap bar))).
+
+Read-time optionals are expression-oriented, not line-oriented, so
+the closing brackets need not be placed on the following line.  Some
+Scheme implementations, and SRFI 62, also support expression comments
+with `#;', which are operationally equivalent to the above read-time
+optionals for Common Lisp:
+
+  (define (foo bar)
+    (list (frob bar)
+          (zork bar)
+          #;
+           (zap bar)))
+
+The expression is placed on another line in order to avoid confusing
+editors that do not recognize S-expression comments; see the section
+titled `Comments' below for more details.  However, the `#;' notation
+is not standard -- it appears in neither the IEEE 1178 document nor in
+the R5RS --, so line comments are preferable for portable Scheme code,
+even if they require breaking a line before a sequence of closing
+brackets.
+
+Finally, it is acceptable to break a line immediately after an opening
+bracket and immediately before a closing bracket for very long lists,
+especially in files under version control.  This eases the maintenance
+of the lists and clarifies version diffs.  Example:
+
+  (define colour-names         ;Add more colour names to this list!
+    '(
+      blue
+      cerulean
+      green
+      magenta
+      purple
+      red
+      scarlet
+      turquoise
+      ))
+
+,*** Parenthetical Philosophy
+
+The actual bracket characters are simply lexical tokens to which little
+significance should be assigned.  Lisp programmers do not examine the
+brackets individually, or, Azathoth forbid, count brackets; instead
+they view the higher-level structures expressed in the program,
+especially as presented by the indentation.  Lisp is not about writing
+a sequence of serial instructions; it is about building complex
+structures by summing parts.  The composition of complex structures
+from parts is the focus of Lisp programs, and it should be readily
+apparent from the Lisp code.  Placing brackets haphazardly about the
+presentation is jarring to a Lisp programmer, who otherwise would not
+even have seen them for the most part.
+
+,** Indentation and Alignment
+
+The operator of any form, i.e. the first subform following the opening
+round bracket, determines the rules for indenting or aligning the
+remaining forms.  Many names in this position indicate special
+alignment or indentation rules; these are special operators, macros, or
+procedures that have certain parameter structures.
+
+If the first subform is a non-special name, however, then if the second
+subform is on the same line, align the starting column of all following
+subforms with that of the second subform.  If the second subform is on
+the following line, align its starting column with that of the first
+subform, and do the same for all remaining subforms.
+
+In general, Emacs will indent Lisp code correctly.  Run `C-M-q'
+(indent-sexp) on any code to ensure that it is indented correctly, and
+configure Emacs so that any non-standard forms are indented
+appropriately.
+
+  Unacceptable:
+
+    (+ (sqrt -1)
+      (* x y)
+      (+ p q))
+
+    (+
+       (sqrt -1)
+       (* x y)
+       (+ p q))
+
+  Acceptable:
+
+    (+ (sqrt -1)
+       (* x y)
+       (+ p q))
+
+    (+
+     (sqrt -1)
+     (* x y)
+     (+ p q))
+
+  Rationale:  The columnar alignment allows the reader to follow the
+  operands of any operation straightforwardly, simply by scanning
+  downward or upward to match a common column.  Indentation dictates
+  structure; confusing indentation is a burden on the reader who wishes
+  to derive structure without matching parentheses manually.
+
+,*** Non-Symbol Indentation and Alignment
+
+The above rules are not exhaustive; some cases may arise with strange
+data in operator positions.
+
+,**** Lists
+
+Unfortunately, style varies here from person to person and from editor
+to editor.  Here are some examples of possible ways to indent lists
+whose operators are lists:
+
+  Questionable:
+
+    ((car x)                            ;Requires hand indentation.
+       (cdr x)
+       foo)
+
+    ((car x) (cdr x)                    ;GNU Emacs
+     foo)
+
+  Preferable:
+
+    ((car x)                            ;Any Emacs
+     (cdr x)
+     foo)
+
+    ((car x) (cdr x)                    ;Edwin
+             foo)
+
+  Rationale:  The operands should be aligned, as if it were any other
+  procedure call with a name in the operator position; anything other
+  than this is confusing because it gives some operands greater visual
+  distinction, allowing others to hide from the viewer's sight.  For
+  example, the questionable indentation
+
+    ((car x) (cdr x)
+     foo)
+
+  can make it hard to see that FOO and (CDR X) are both operands here
+  at the same level.  However, GNU Emacs will generate that indentation
+  by default.  (Edwin will not.)
+
+,**** Strings
+
+If the form in question is meant to be simply a list of literal data,
+all of the subforms should be aligned to the same column, irrespective
+of the first subform.
+
+  Unacceptable:
+
+    ("foo" "bar" "baz" "quux" "zot"
+           "mumble" "frotz" "gargle" "mumph")
+
+  Questionable, but acceptable:
+
+    (3 1 4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6 2 6 4
+       3 3 8 3 2 7 9 5 0 2 8 8 4 1 9 7 1 6 9 3 9 9 3)
+
+  Acceptable:
+
+    ("foo" "bar" "baz" "quux" "zot"
+     "mumble" "frotz" "gargle" "mumph")
+
+    ("foo"
+     "bar" "baz" "quux" "zot"
+     "mumble" "frotz" "gargle" "mumph")
+
+  Rationale:  Seldom is the first subform distinguished for any reason,
+  if it is a literal; usually in this case it indicates pure data, not
+  code.  Some editors and pretty-printers, however, will indent
+  unacceptably in the example given unless the second subform is on the
+  next line anyway, which is why the last way to write the fragment is
+  usually best.
+
+,** Names
+
+Naming is subtle and elusive.  Bizarrely, it is simultaneously
+insignificant, because an object is independent of and unaffected by
+the many names by which we refer to it, and also of supreme
+importance, because it is what programming -- and, indeed, almost
+everything that we humans deal with -- is all about.  A full
+discussion of the concept of name lies far outside the scope of this
+document, and could surely fill not even a book but a library.
+
+Symbolic names are written with English words separated by hyphens.
+Scheme and Common Lisp both fold the case of names in programs;
+consequently, camel case is frowned upon, and not merely because it is
+ugly.  Underscores are unacceptable separators except for names that
+were derived directly from a foreign language without translation.
+
+  Unacceptable:
+
+    XMLHttpRequest
+    foreach
+    append_map
+
+  Acceptable:
+
+    xml-http-request
+    for-each
+    append-map
+
+,*** Funny Characters
+
+There are several different conventions in different Lisps for the use
+of non-alphanumeric characters in names.
+
+,**** Scheme
+
+,***** Question Marks: Predicates
+
+Affix a question mark to the end of a name for a procedure whose
+purpose is to ask a question of an object and to yield a boolean
+answer.  Such procedures are called `predicates'.  Do not use a
+question mark if the procedure may return any object other than a
+boolean.
+
+  Examples:  pair? procedure? proper-list?
+  Non-examples:  member assoc any every
+
+Pronounce the question mark as if it were the isolated letter `p'.  For
+example, to read the fragment (PAIR? OBJECT) aloud, say: `pair-pee
+object.'
+
+,***** Exclamation Marks: Destructive Operations
+
+Affix an exclamation mark to the end of a name for a procedure (or
+macro) whose primary purpose is to modify an object.  Such procedures
+are called `destructive'.
+
+  Examples: set-car! append!
+
+Avoid using the exclamation mark willy nilly for just *any* procedure
+whose operation involves any kind of mutation or side effect; instead,
+use the exclamation mark to identify procedures that exist *solely* for
+the purpose of destructive update (e.g., SET-CAR!), or to distinguish a
+destructive, or potentially destructive (in the case of linear-update
+operations such as APPEND!), variant of a procedure of which there also
+exists a purely functional variant (e.g., APPEND).
+
+Pronounce the exclamation mark as `bang'.  For example, to read the
+fragment (APPEND! LIST TAIL) aloud, say: `append-bang list tail.'
+
+,***** Asterisks: Variants, Internal Routines, Mutable Globals
+
+Affix an asterisk to the end of a name to make a variation on a theme
+of the original name.
+
+  Example: let -> let*
+
+Prefer a meaningful name over an asterisk; the asterisk does not
+explain what variation on the theme the name means.
+
+Affix an asterisk to the beginning of a name to make an internal
+routine for that name.  Again, prefer a meaningful name over an
+asterisk.
+
+Affix asterisks to the beginning and end of a globally mutable
+variable.  This allows the reader of the program to recognize very
+easily that it is badly written!
+
+,***** `WITH-' and `CALL-WITH-': Dynamic State and Cleanup
+
+Prefix `WITH-' to any procedure that establishes dynamic state and
+calls a nullary procedure, which should be the last (required)
+argument.  The dynamic state should be established for the extent of
+the nullary procedure, and should be returned to its original state
+after that procedure returns.
+
+  Examples: with-input-from-file with-output-to-file
+
+  Exception:  Some systems provide a procedure (WITH-CONTINUATION
+  <continuation> <thunk>), which calls <thunk> in the given
+  continuation, using that continuation's dynamic state.  If <thunk>
+  returns, it will return to <continuation>, not to the continuation of
+  the call to WITH-CONTINUATION.  This is acceptable.
+
+Prefix `CALL-WITH-' to any procedure that calls a procedure, which
+should be its last argument, with some arguments, and is either somehow
+dependent upon the dynamic state or continuation of the program, or
+will perform some action to clean up data after the procedure argument
+returns.  Generally, `CALL-WITH-' procedures should return the values
+that the procedure argument returns, after performing the cleaning
+action.
+
+  Examples:
+
+  - CALL-WITH-INPUT-FILE and CALL-WITH-OUTPUT-FILE both accept a
+    pathname and a procedure as an argument, open that pathname (for
+    input or output, respectively), and call the procedure with one
+    argument, a port corresponding with the file named by the given
+    pathname.  After the procedure returns, CALL-WITH-INPUT-FILE and
+    CALL-WITH-OUTPUT-FILE close the file that they opened, and return
+    whatever the procedure returned.
+
+  - CALL-WITH-CURRENT-CONTINUATION is dependent on the continuation
+    with which it was called, and passes as an argument an escape
+    procedure corresponding with that continuation.
+
+  - CALL-WITH-OUTPUT-STRING, a common but non-standard procedure
+    definable in terms of OPEN-OUTPUT-STRING and GET-OUTPUT-STRING from
+    SRFI 6 (Basic String Ports), calls its procedure argument with an
+    output port, and returns a string of all of the output written to
+    that port.  Note that it does not return what the procedure
+    argument returns, which is an exception to the above rule.
+
+Generally, the distinction between these two classes of procedures is
+that `CALL-WITH-...' procedures should not establish fresh dynamic
+state and instead pass explicit arguments to their procedure arguments,
+whereas `WITH-...' should do the opposite and establish dynamic state
+while passing zero arguments to their procedure arguments.
+
+,** Comments
+
+Write heading comments with at least four semicolons; see also the
+section below titled `Outline Headings'.
+
+Write top-level comments with three semicolons.
+
+Write comments on a particular fragment of code before that fragment
+and aligned with it, using two semicolons.
+
+Write margin comments with one semicolon.
+
+The only comments in which omission of a space between the semicolon
+and the text is acceptable are margin comments.
+
+  Examples:
+
+    ;;;; Frob Grovel
+
+    ;;; This section of code has some important implications:
+    ;;;   1. Foo.
+    ;;;   2. Bar.
+    ;;;   3. Baz.
+
+    (define (fnord zarquon)
+      ;; If zob, then veeblefitz.
+      (quux zot
+            mumble             ;Zibblefrotz.
+            frotz))
+
+,* Riastradh's Non-Standard Rules
+
+Three principles guide this style, roughly ordered according to
+descending importance:
+
+1. The purpose of a program is to describe an idea, and not the way
+   that the idea must be realized; the intent of the program's meaning,
+   rather than peripheral details that are irrelevant to its intent,
+   should be the focus of the program, *irrespective* of whether a
+   human or a machine is reading it.  [It would be nice to express this
+   principle more concisely.]
+
+2. The sum of the parts is easier to understand than the whole.
+
+3. Aesthetics matters.  No one enjoys reading an ugly program.
+
+,** General Layout
+
+This section contains rules that the author has found generally helpful
+in keeping his programs clean and presentable, though they are not
+especially philosophically interesting.
+
+Contained in the rationale for some of the following rules are
+references to historical limitations of terminals and printers, which
+are now considered aging cruft of no further relevance to today's
+computers.  Such references are made only to explain specific measures
+chosen for some of the rules, such as a limit of eighty columns per
+line, or sixty-six lines per page.  There is a real reason for each of
+the rules, and this real reason is not intrinsically related to the
+historical measures, which are mentioned only for the sake of
+providing some arbitrary measure for the limit.
+
+,*** File Length
+
+If a file exceeds five hundred twelve lines, begin to consider
+splitting it into multiple files.  Do not write program files that
+exceed one thousand twenty-four lines.  Write a concise but
+descriptive title at the top of each file, and include no content in
+the file that is unrelated to its title.
+
+  Rationale:  Files that are any larger should generally be factored
+  into smaller parts.  (One thousand twenty-four is a nicer number than
+  one thousand.)  Identifying the purpose of the file helps to break it
+  into parts if necessary and to ensure that nothing unrelated is
+  included accidentally.
+
+,*** Top-Level Form Length
+
+Do not write top-level forms that exceed twenty-one lines, except for
+top-level forms that serve only the purpose of listing large sets of
+data.  If a procedure exceeds this length, split it apart and give
+names to its parts.  Avoid names formed simply by appending a number
+to the original procedure's name; give meaningful names to the parts.
+
+  Rationale:  Top-level forms, especially procedure definitions, that
+  exceed this length usually combine too many concepts under one name.
+  Readers of the code are likely to more easily understand the code if
+  it is composed of separately named parts.  Simply appending a number
+  to the original procedure's name can help only the letter of the
+  rule, not the spirit, however, even if the procedure was taken from a
+  standard algorithm description.  Using comments to mark the code with
+  its corresponding place in the algorithm's description is acceptable,
+  but the algorithm should be split up in meaningful fragments anyway.
+
+  Rationale for the number twenty-one:  Twenty-one lines, at a maximum
+  of eighty columns per line, fits in a GNU Emacs instance running in a
+  24x80 terminal.  Although the terminal may have twenty-four lines,
+  three of the lines are occupied by GNU Emacs: one for the menu bar
+  (which the author of this guide never uses, but which occupies a line
+  nevertheless in a vanilla GNU Emacs installation), one for the mode
+  line, and one for the minibuffer's window.  The writer of some code
+  may not be limited to such a terminal, but the author of this style
+  guide often finds it helpful to have at least four such terminals or
+  Emacs windows open simultaneously, spread across a twelve-inch laptop
+  screen, to view multiple code fragments.
+
+,*** Line Length
+
+Do not write lines that exceed eighty columns, or if possible
+seventy-two.
+
+  Rationale:  Following multiple lines that span more columns is
+  difficult for humans, who must remember the line of focus and scan
+  right to left from the end of the previous line to the beginning of
+  the next line; the more columns there are, the harder this is to do.
+  Sticking to a fixed limit helps to improve readability.
+
+  Rationale for the numbers eighty and seventy-two:  It is true that we
+  have very wide screens these days, and we are no longer limited to
+  eighty-column terminals; however, we ought to exploit our wide
+  screens not by writing long lines, but by viewing multiple fragments
+  of code in parallel, something that the author of this guide does
+  very often.  Seventy-two columns leave room for several nested layers
+  of quotation in email messages before the code reaches eighty
+  columns.  Also, a fixed column limit yields nicer printed output,
+  especially in conjunction with pagination; see the section
+  `Pagination' below.
+
+,*** Blank Lines
+
+Separate each adjacent top-level form with a single blank line (i.e.
+two line breaks).  If two blank lines seem more appropriate, break the
+page instead.  Do not place blank lines in the middle of a procedure
+body, except to separate internal definitions; if there is a blank
+line for any other reason, split the top-level form up into multiple
+ones.
+
+  Rationale:  More than one blank line is distracting and sloppy.  If
+  the two concepts that are separated by multiple blank lines are
+  really so distinct that such a wide separator is warranted, then
+  they are probably better placed on separate pages anyway; see the
+  next section, `Pagination'.
+
+,*** Pagination
+
+Separate each file into pages of no more than sixty-six lines and no
+fewer than forty lines with form feeds (ASCII #x0C, or ^L, written in
+Emacs with `C-q C-l'), on either side of which is a single line break
+(but not a blank line).
+
+  Rationale:  Keeping distinct concepts laid out on separate pages
+  helps to keep them straight.  This is helpful not only for the
+  writer of the code, but also for the reader.  It also allows readers
+  of the code to print it onto paper without fiddling with printer
+  settings to permit pages of more than sixty-six lines (which is the
+  default number for many printers), and pagination also makes the
+  code easier to navigate in Emacs, with the `C-x [' and `C-x ]' keys
+  (`backward-page' and `forward-page', respectively).  To avoid
+  excessively small increments of page-by-page navigation, and to
+  avoid wasting paper, each page should generally exceed forty lines.
+
+  `C-x l' in Emacs will report the number of lines in the page on which
+  the point lies; this is useful for finding where pagination is
+  necessary.
+
+,*** Outline Headings
+
+Use Emacs's Outline Mode to give titles to the pages, and if
+appropriate a hierarchical structure.  Set `outline-regexp' (or
+`outline-pattern' in Edwin) to "\f\n;;;;+ ", so that each form feed
+followed by an line break followed by at least four semicolons and a
+space indicates an outline heading to Emacs.  Use four semicolons for
+the highest level of headings in the hierarchy, and one more for each
+successively nested level of hierarchy.
+
+  Rationale:  Not only does this clarify the organization of the code,
+  but readers of the code can then navigate the code's structure with
+  Outline Mode commands such as `C-c C-f', `C-c C-b', `C-c C-u', and
+  `C-c C-d' (forward, backward, up, down, respectively, headings).
+
+,*** Dependencies
+
+When writing a file or module, minimize its dependencies.  If there are
+too many dependencies, consider breaking the module up into several
+parts, and writing another module that is the sum of the parts and that
+depends only on the parts, not their dependencies.
+
+  Rationale:  A fragment of a program with fewer dependencies is less
+  of a burden on the reader's cognition.  The reader can more easily
+  understand the fragment in isolation; humans are very good at local
+  analyses, and terrible at global ones.
+
+,** Naming
+
+This section requires an elaborate philosophical discussion which the
+author is too ill to have the energy to write at this moment.
+
+Compose concise but meaningful names.  Do not cheat by abbreviating
+words or using contractions.
+
+  Rationale:  Abbreviating words in names does not make them shorter;
+  it only makes them occupy less screen space.  The reader still must
+  understand the whole long name.  This does not mean, however, that
+  names should necessarily be long; they should be descriptive.  Some
+  long names are more descriptive than some short names, but there are
+  also descriptive names that are not long and long names that are not
+  descriptive.  Here is an example of a long name that is not
+  descriptive, from SchMUSE, a multi-user simulation environment
+  written in MIT Scheme:
+
+    frisk-descriptor-recursive-subexpr-descender-for-frisk-descr-env
+
+  Not only is it long (sixty-four characters) and completely
+  impenetrable, but halfway through its author decided to abbreviate
+  some words as well!
+
+Do not write single-letter variable names.  Give local variables
+meaningful names composed from complete English words.
+
+  Rationale:  It is tempting to reason that local variables are
+  invisible to other code, so it is OK to be messy with their names.
+  This is faulty reasoning: although the next person to come along and
+  use a library may not care about anything but the top-level
+  definitions that it exports, this is not the only audience of the
+  code.  Someone will also want to read the code later on, and if it is
+  full of impenetrably terse variable names without meaning, that
+  someone will have a hard time reading the code.
+
+Give names to intermediate values where their expressions do not
+adequately describe them.
+
+  Rationale:  An `expression' is a term that expresses some value.
+  Although a machine needs no higher meaning for this value, and
+  although it should be written to be sufficiently clear for a human to
+  understand what it means, the expression might mean something more
+  than just what it says where it is used.  Consequently, it is helpful
+  for humans to see names given to expressions.
+
+  Example:  A hash table HASH-TABLE maps foos to bars; (HASH-TABLE/GET
+  HASH-TABLE FOO #F) expresses the datum that HASH-TABLE maps FOO to,
+  but that expression gives the reader no hint of any information
+  concerning that datum.  (LET ((BAR (HASH-TABLE/GET HASH-TABLE FOO
+  #F))) ...)  gives a helpful name for the reader to understand the
+  code without having to find the definition of HASH-TABLE.
+
+  Index variables such as i and j, or variables such as A and D naming
+  the car and cdr of a pair, are acceptable only if they are completely
+  unambiguous in the scope.  For example,
+
+    (do ((i 0 (+ i 1)))
+        ((= i (vector-length vector)))
+      (frobnicate (vector-ref vector i)))
+
+  is acceptable because the scope of i is very clearly limited to a
+  single vector.  However, if more vectors are involved, using more
+  index variables such as j and k will obscure the program further.
+
+Avoid functional combinators, or, worse, the point-free (or
+`point-less') style of code that is popular in the Haskell world.  At
+most, use function composition only where the composition of functions
+is the crux of the idea being expressed, rather than simply a procedure
+that happens to be a composition of two others.
+
+  Rationale:  Tempting as it may be to recognize patterns that can be
+  structured as combinations of functional combinators -- say, `compose
+  this procedure with the projection of the second argument of that
+  other one', or (COMPOSE FOO (PROJECT 2 BAR)) --, the reader of the
+  code must subsequently examine the elaborate structure that has been
+  built up to obscure the underlying purpose.  The previous fragment
+  could have been written (LAMBDA (A B) (FOO (BAR B))), which is in
+  fact shorter, and which tells the reader directly what argument is
+  being passed on to what, and what argument is being ignored, without
+  forcing the reader to search for the definitions of FOO and BAR or
+  the call site of the final composition.  The explicit fragment
+  contains substantially more information when intermediate values are
+  named, which is very helpful for understanding it and especially for
+  modifying it later on.
+
+  The screen space that can be potentially saved by using functional
+  combinators is made up for by the cognitive effort on the part of the
+  reader.  The reader should not be asked to search globally for usage
+  sites in order to understand a local fragment.  Only if the structure
+  of the composition really is central to the point of the narrative
+  should it be written as such.  For example, in a symbolic integrator
+  or differentiator, composition is an important concept, but in most
+  code the structure of the composition is completely irrelevant to the
+  real point of the code.
+
+If a parameter is ignored, give it a meaningful name nevertheless and
+say that it is ignored; do not simply call it `ignored'.
+
+In Common Lisp, variables can be ignored with (DECLARE (IGNORE ...)).
+Some Scheme systems have similar declarations, but the portable way to
+ignore variables is just to write them in a command context, where
+their values will be discarded, preferably with a comment indicating
+this purpose:
+
+  (define (foo x y z)
+    x z                         ;ignore
+    (frobnitz y))
+
+  Rationale:  As with using functional combinators to hide names,
+  avoiding meaningful names for ignored parameters only obscures the
+  purpose of the program.  It is helpful for a reader to understand
+  what parameters a procedure is independent of, or if someone wishes
+  to change the procedure later on, it is helpful to know what other
+  parameters are available.  If the ignored parameters were named
+  meaninglessly, then these people would be forced to search for call
+  sites of the procedure in order to get a rough idea of what
+  parameters might be passed here.
+
+When naming top-level bindings, assume namespace partitions unless in a
+context where they are certain to be absent.  Do not write explicit
+namespace prefixes, such as FOO:BAR for an operation BAR in a module
+FOO, unless the names will be used in a context known not to have any
+kind of namespace partitions.
+
+  Rationale:  Explicit namespace prefixes are ugly, and lengthen names
+  without adding much semantic content.  Common Lisp has its package
+  system to separate the namespaces of symbols; most Schemes have
+  mechanisms to do so as well, even if the RnRS do not specify any.  It
+  is better to write clear names which can be disambiguated if
+  necessary, rather than to write names that assume some kind of
+  disambiguation to be necessary to begin with.  Furthermore, explicit
+  namespace prefixes are inadequate to cover name clashes anyway:
+  someone else might choose the same namespace prefix.  Relegating this
+  issue to a module system removes it from the content of the program,
+  where it is uninteresting.
+
+,** Comments
+
+Write comments only where the code is incapable of explaining itself.
+Prefer self-explanatory code over explanatory comments.  Avoid
+`literate programming' like the plague.
+
+  Rationale:  If the code is often incapable of explaining itself, then
+  perhaps it should be written in a more expressive language.  This may
+  mean using a different programming language altogether, or, since we
+  are talking about Lisp, it may mean simply building a combinator
+  language or a macro language for the purpose.  `Literate programming'
+  is the logical conclusion of languages incapable of explaining
+  themselves; it is a direct concession of the inexpressiveness of the
+  computer language implementing the program, to the extent that the
+  only way a human can understand the program is by having it rewritten
+  in a human language.
+
+Do not write interface documentation in the comments for the
+implementation of the interface.  Explain the interface at the top of
+the file if it is a single-file library, or put that documentation in
+another file altogether.  (See the `Documentation' section below if the
+interface documentation comments grow too large for a file.)
+
+  Rationale:  A reader who is interested only in the interface really
+  should not need to read through the implementation to pick out its
+  interface; by putting the interface documentation at the top, not
+  only is such a reader's task of identifying the interface made
+  easier, but the implementation code can be more liberally commented
+  without fear of distracting this reader.  To a reader who is
+  interested in the implementation as well, the interface is still
+  useful in order to understand what concepts the implementation is
+  implementing.
+
+  Example: <http://mumble.net/~campbell/scheme/skip-list.scm>
+
+  In this example of a single-file library implementing the skip list
+  data structure, the first page explains the purpose and dependencies
+  of the file (which are useful for anyone who intends to use it, even
+  though dependencies are really implementation details), and the next
+  few pages explain the usage of skip lists as implemented in that
+  file.  On the first page of implementation, `Skip List Structure',
+  there are some comments of interest only to a reader who wishes to
+  understand the implementation; the same goes for the rest of the
+  file, none of which must a reader read whose interest is only in the
+  usage of the library.
+
+Avoid block comments (i.e. #| ... |#).  Use S-expression comments (`#;'
+in Scheme, with the expression to comment on the next line; `#+(OR)' or
+`#-(AND)' in Common Lisp) to comment out whole expressions.  Use blocks
+of line comments for text.
+
+  Rationale:  Editor support for block comments is weak, because it
+  requires keeping a detailed intermediate parse state of the whole
+  buffer, which most Emacsen do not do.  At the very least, #|| ... ||#
+  is better, because most Emacsen will see vertical bars as symbol
+  delimiters, and lose trying to read a very, very long symbol, if they
+  try to parse #| ... |#, whereas they will just see two empty symbols
+  and otherwise innocuous text between them if they try to parse #||
+  ... ||#.  In any case, in Emacs, `M-x comment-region RET', or `M-;'
+  (comment-dwim), is trivial to type.
+
+  The only standard comments in Scheme are line comments.  There are
+  SRFIs for block comments and S-expression comments, but support for
+  them varies from system to system.  Expression comments are not hard
+  for editors to deal with because it is safe not to deal with them at
+  all; however, in Scheme S-expression comments, which are written by
+  prefixing an expression with `#;', the expression to be commented
+  should be placed on the next line.  This is because editors that do
+  not deal with them at all may see the semicolon as the start of a
+  line comment, which will throw them off.  Expression comments in
+  Common Lisp, however, are always safe.
+
+  In Common Lisp, the two read-time optionals that are guaranteed to
+  ignore any form following them are `#+(OR)' and `#-(AND)'.  `#+NIL'
+  is sometimes used in their stead, but, while it may appear to be an
+  obviously false optional, it actually is not.  The feature
+  expressions are read in the KEYWORD package, so NIL is read not as
+  CL:NIL, i.e. the boolean false value, but as :NIL, a keyword symbol
+  whose name happens to be `NIL'.  Not only is it not read as the
+  boolean false value, but it has historically been used to indicate a
+  feature that might be enabled -- in JonL White's New Implementation
+  of Lisp!  However, the New Implementation of Lisp is rather old these
+  days, and unlikely to matter much...until Alastair Bridgewater writes
+  Nyef's Implementation of Lisp.
+
+,** Documentation
+
+On-line references and documentation/manuals are both useful for
+independent purposes, but there is a very fine distinction between
+them.  Do not generate documentation or manuals automatically from the
+text of on-line references.
+
+  Rationale: /On-line references/ are quick blurbs associated with
+  objects in a running Lisp image, such as documentation strings in
+  Common Lisp or Emacs Lisp.  These assume that the reader is familiar
+  with the gist of the surrounding context, but unclear on details;
+  on-line references specify the details of individual objects.
+
+  /Documentation/ and /manuals/ are fuller, organized, and cohesive
+  documents that explain the surrounding context to readers who are
+  unfamiliar with it.  A reader should be able to pick a manual up and
+  begin reading it at some definite point, perusing it linearly to
+  acquire an understanding of the subject.  Although manuals may be
+  dominated by reference sections, they should still have sections that
+  are linearly readable to acquaint the reader with context.
+
+,** Round and Square Brackets
+
+Some implementations of Scheme provide a non-standard extension of the
+lexical syntax whereby balanced pairs of square brackets are
+semantically indistinguishable from balanced pairs of round brackets.
+Do not use this extension.
+
+  Rationale:  Because this is a non-standard extension, it creates
+  inherently non-portable code, of a nature much worse than using a
+  name in the program which is not defined by the R5RS.  The reason
+  that we have distinct typographical symbols in the first place is to
+  express different meaning.  The only distinction between round
+  brackets and square brackets is in convention, but the precise nature
+  of the convention is not specified by proponents of square brackets,
+  who suggest that they be used for `clauses', or for forms that are
+  parts of enclosing forms.  This would lead to such constructions as
+
+    (let [(x 5) (y 3)] ...)
+
+  or
+
+    (let ([x 5] [y 3]) ...)
+
+  or
+
+    (let [[x 5] [y 3]] ...),
+
+  the first two of which the author of this guide has seen both of, and
+  the last of which does nothing to help to distinguish the parentheses
+  anyway.
+
+  The reader of the code should not be forced to stumble over a
+  semantic identity because it is expressed by a syntactic distinction.
+  The reader's focus should not be directed toward the lexical tokens;
+  it should be directed toward the structure, but using square brackets
+  draws the reader's attention unnecessarily to the lexical tokens.
+
+,* Attribution
+
+#+END_SRC
+:END:
+
+**** TODO I have to get change (let ([x 5] [y 3])) -> (let ((x 5) (y 3)))
+**** TODO comments
+
+#+BEGIN_SRC scheme
+  ;;;; Frob Grovel
+
+    ;;; This section of code has some important implications:
+    ;;;   1. Foo.
+    ;;;   2. Bar.
+    ;;;   3. Baz.
+
+    (define (fnord zarquon)
+      ;; If zob, then veeblefitz.
+      (quux zot
+            mumble             ;Zibblefrotz.
+            frotz))
+
+#+END_SRC
+**** TODO literal data
+Strings
+
+If the form in question is meant to be simply a list of literal data,
+all of the subforms should be aligned to the same column, irrespective
+of the first subform.
+
+  Unacceptable:
+
+    ("foo" "bar" "baz" "quux" "zot"
+           "mumble" "frotz" "gargle" "mumph")
+
+  Questionable, but acceptable:
+
+    (3 1 4 1 5 9 2 6 5 3 5 8 9 7 9 3 2 3 8 4 6 2 6 4
+       3 3 8 3 2 7 9 5 0 2 8 8 4 1 9 7 1 6 9 3 9 9 3)
+
+  Acceptable:
+
+    ("foo" "bar" "baz" "quux" "zot"
+     "mumble" "frotz" "gargle" "mumph")
+
+    ("foo"
+     "bar" "baz" "quux" "zot"
+     "mumble" "frotz" "gargle" "mumph")
+**** TODO follow this syntax convention proc args
+
+:alignment:
+The operator of any form, i.e. the first subform following the opening
+round bracket, determines the rules for indenting or aligning the
+remaining forms.  Many names in this position indicate special
+alignment or indentation rules; these are special operators, macros, or
+procedures that have certain parameter structures.
+
+If the first subform is a non-special name, however, then if the second
+subform is on the same line, align the starting column of all following
+subforms with that of the second subform.  If the second subform is on
+the following line, align its starting column with that of the first
+subform, and do the same for all remaining subforms.
+
+In general, Emacs will indent Lisp code correctly.  Run `C-M-q'
+(indent-sexp) on any code to ensure that it is indented correctly, and
+configure Emacs so that any non-standard forms are indented
+appropriately.
+
+  Unacceptable:
+
+    (+ (sqrt -1)
+      (* x y)
+      (+ p q))
+
+    (+
+       (sqrt -1)
+       (* x y)
+       (+ p q))
+
+  Acceptable:
+
+    (+ (sqrt -1)
+       (* x y)
+       (+ p q))
+
+    (+
+     (sqrt -1)
+     (* x y)
+     (+ p q))
+
+  Rationale:  The columnar alignment allows the reader to follow the
+  operands of any operation straightforwardly, simply by scanning
+  downward or upward to match a common column.  Indentation dictates
+  structure; confusing indentation is a burden on the reader who wishes
+  to derive structure without matching parentheses manually.
+
+:END:
+
+If you have a procedure, then it's arguments should be on the same line.
+#+BEGIN_SRC scheme
+(proc args
+      (proc (proc
+             args)
+            (proc args)
+            (proc (proc
+                   args)
+                  (proc (proc
+                         (proc (proc
+                                args))))))
+      + (proc (proc
+               args)))
+#+END_SRC
+
+*** TODO write various tests for =<opensmtpd-configuration>=
+
+I have many bits of code in opensmtpd.org.archive that should result in an
+error.  I should write some tests for this.
+** NO should I modifiy some of the records to include a sanitize field?
+Probably not.  It would be cool if this function ran automatically upon record
+initiation, but there's no to make it do that.
+** TODO which sanitize function is better?  Pick the better sanitize method and use that one.
+
+The sanitize function found in opensmtpd-listen-on-configuration-filters
+
+Or the sanitize function
+sanitize-list-of-options-for-match-configuration ?
+
+sanitize-list-of-options-for-match-configuration is probably faster. But is it?
+It is an iteratize loop that checks for all issues as it loops through the
+options. There is a lot of repetitive code in this procedure.
+
+BUT opensmtpd-listen-on-configuration-filters certainly seems easier to follow.
+** TODO remove opensmtpd-table-type fieldname and instead move that it its own procedure outside of the record
+
+ONly use one function instead of
+
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is an assoc-list, then it returns
+;; #t, #f if otherwise.
+;; TODO should I remove these two functions?  And instead use the (opensmtpd-table-configuration-type) procedure?
+(define (table-whose-data-are-assoc-list? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (assoc-list? (opensmtpd-table-configuration-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is a list of strings, then it returns
+;; #t, #f if otherwise.
+(define (table-whose-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (list-of-strings? (opensmtpd-table-configuration-data table))))
+
+      And opensmtpd-table-type
+** TODO OpenSMTPD Service documentation
+
+OpenSMTPD is an easy-to-use mail transfer agent (MTA). Its configuration file is
+throughly documented in man 5 =smtpd.conf=. OpenSMTPD *listens* for incoming
+mail and *matches* the mail to *actions*. The following records represent those
+stages: ~<opensmtpd-listen-on-configuration>~,
+~<opensmtpd-listen-on-socket-configuration>=, =<opensmtpd-match-configuration>~,
+~<opensmtpd-action-local-delivery-configuration>~, and
+~<opensmtpd-action-relay-configuration>~.
+
+Additionally, each ~<opensmtpd-listen-on-configuration>~ and
+~<opensmtpd-listen-on-socket-configuration>~ may use a list of
+~<opensmtpd-filter-configuration>~, and/or
+~<opensmtpd-filter-phase-configuration>~ records to filter email/spam. Also
+numerous records' fieldnames use ~<opensmtpd-table-configuration>~ to hold lists
+or key value pairs of data.
+
+A simple example configuration is below:
+
+#+BEGIN_SRC scheme
+(let ((smtp.gnu.org (opensmtpd-pki-configuration
+                        (domain "smtp.gnu.org")
+                        (cert "file.cert")
+                        (key "file.key"))))
+  (service opensmtpd-service-type
+           (opensmtpd-configuration
+            (listen-ons (list
+                         (opensmtpd-listen-on-configuration
+                          (pki smtp.gnu.org))
+                         (opensmtpd-listen-on-configuration
+                          (pki smtp.gnu.org)
+                          (secure-connection "smtps"))))
+            (matches (list
+                      (opensmtpd-match-configuration
+                       (action
+                        (opensmtpd-action-local-delivery-configuration
+                         (name "local-delivery"))))
+                      (opensmtpd-match-configuration
+                       (action
+                        (opensmtpd-action-relay-configuration
+                         (name "relay")))))))))
+#+END_SRC
+
+- Scheme Variable: opensmtpd-service-type
+
+  Service type for the OpenSMTPD ([[https://www.opensmtpd.org][https://www.opensmtpd.org]]) email server. The
+  value for this service type is a  ~<opensmtpd-configuration>~ record.
+
+- Data Type: opensmtpd-configuration
+
+  Data type representing the configuration of OpenSMTPD.
+
+  - ~package~ (default: ~opensmtpd~)
+
+       The OpenSMTPD package to use.
+
+  - ~config-file~ (default: ~#f~)
+
+    File-like object of the OpenSMTPD configuration file to use.  By default it
+    listens on the loopback network interface, and allows for mail from users
+    and daemons on the local machine, as well as permitting email to remote
+    servers.  Run ~man smtpd.conf~ for more information.
+
+  - ~bounce~ (default: ~(list "4h")~)
+
+    ~bounce~ is a list of strings, which send warning messages to the envelope
+    sender when temporary delivery failures cause a message to remain in the
+    queue for longer than string _delay_. Each string _delay_ parameter consists
+    of a string beginning with a positive decimal integer and a unit s, m, h,
+    or d. At most four delay parameters can be specified.
+
+  - ~listen-ons~ (default: ~(list (opensmtpd-listen-on-configuration))~ )
+
+    ~listen-ons~ is a list of ~<opensmtpd-listen-on-configuration>~ records.
+    This list details what interfaces and ports OpenSMTPD listens on as well as
+    other information.
+
+  - ~listen-on-socket~ (default: ~(opensmtpd-listen-on-socket-configuration-configuration)~ )
+
+    Listens for incoming connections on the Unix domain socket.
+
+  - ~includes~ (default: ~#f~)
+
+    # TODO ~includes~ should support a list of string filenames or gexps.
+    ~includes~ is a list of string _filenames_. Each filename's contents is
+    additional configuration that is inserted into the top of the configuration
+    file.
+
+  - ~matches~ default:
+
+    #+BEGIN_SRC scheme
+    (list (opensmtpd-match-configuration
+           (action (opensmtpd-action-local-delivery-configuration
+                    (name "local")
+                    (method "mbox")))
+           (for (opensmtpd-option-configuration
+                 (option "for local"))))
+          (opensmtpd-match-configuration
+           (action (opensmtpd-action-relay-configuration
+                    (name "outbound")))
+           (from (opensmtpd-option-configuration
+                  (option "from local")))
+           (for (opensmtpd-option-configuration
+                 (option "for any")))))
+    #+END_SRC
+
+    ~matches~ is a list of ~<opensmtpd-match-configuration>~ records, which
+    matches incoming mail and sends it to a correspending action. The match
+    records are evaluated sequentially, with the first match winning. If an
+    incoming mail does not match any match records, then it is rejected.
+
+  # TODO when the code supports mda-wrappers, add in this documentation.
+  # - ~mda-wrappers~
+
+  - ~mta-max-deferred~ (default: ~100~)
+
+   When delivery to a given host is suspended due to temporary failures, cache
+   at most _number_ envelopes for that host such that they can be delivered as
+   soon as another delivery succeeds to that host. The default is 100.
+
+  - ~queue~ (default: ~#f~)
+
+    ~queue~ expects an ~<opensmtpd-queue-configuration>~ record. With it, one may
+    compress and encrypt queue-ed emails as well as set the default expiration
+    time for temporarily undeliverable messages.
+
+  - ~smtp~ (default: ~#f~)
+
+    ~smtp~ expects an ~<opensmtpd-smtp-configuration>~ record, which lets one
+    specifiy how large email may be along with other settings.
+
+  - ~srs~ (default: ~#f~)
+
+    ~srs~ expects an ~<opensmtpd-srs-configuration>~ record, which lets one set
+    up SRS, the Sender Rewritting Scheme.
+
+- Data Type: opensmtpd-listen-on-configuration
+
+  Data type representing the configuration of an
+  ~<opensmtpd-listen-on-configuration>~. Listen on the fieldname ~interface~ for
+  incoming connections, using the same syntax as for ifconfig(8). The interface
+  parameter may also be an string interface group, an string IP address, or a
+  string domain name. Listening can optionally be restricted to a specific
+  address fieldname ~family~, which can be either "inet4" or "inet6".
+
+  - ~interface~ (default: "lo")
+
+    The string interface to listen for incoming connections. These interface can
+    usually be found by the command ~ip link~.
+
+  - ~family~ (default: ~#f~)
+
+    The string IP family to use.  Valid strings are "inet4" or "inet6".
+
+  - ~auth~ (default: ~#f~)
+
+    Support SMTPAUTH: clients may only start SMTP transactions after successful
+    authentication. If ~auth~ is ~#t~, then users are authenticated against
+    their own normal login credentials. Alternatively ~auth~ may be an
+    ~<opensmtpd-table-configuration>~ whose users are authenticated against
+    their passwords.
+
+  - ~auth-optional~ (default: ~#f~)
+
+    Support SMTPAUTH optionally: clients need not authenticate, but may do so.
+    This allows the ~<opensmtpd-listen-on-configuration>~ to both accept
+    incoming mail from untrusted senders and permit outgoing mail from
+    authenticated users (using ~<opensmtpd-match-configuration>~ fieldname
+    ~auth~). It can be used in situations where it is not possible to listen on
+    a separate port (usually the submission port, 587) for users to
+    authenticate.
+
+  - ~filters~ (default: ~#f~)
+
+    A list of one or many ~<opensmtpd-filter-configuration>~ or
+    ~<opensmtpd-filter-phase-configuration>~ records. The filters are applied
+    sequentially. These records listen and filter on connections handled by this
+    listener.
+
+  - ~hostname~ (default: ~#f~)
+
+    Use string "hostname" in the greeting banner instead of the default server
+    name.
+
+  - ~hostnames~ (default: ~#f~)
+
+    Override the server name for specific addresses. Use a
+    ~<opensmtpd-table-configuration>~ containing a mapping of string IP
+    addresses to hostnames. If the address on which the connection arrives
+    appears in the mapping, the associated hostname is used.
+
+  - ~mask-src~ (default: ~#f~)
+
+    If ~#t~, then omit the from part when prepending “Received” headers.
+
+  - ~disable-dsn~ (default: ~#f~)
+
+    When ~#t~, then disable the DSN (Delivery Status Notification) extension.
+
+  - ~pki~ (default: ~#f~)
+
+    For secure connections, use an ~<opensmtpd-pki-configuration>~
+    to prove a mail server's identity.
+
+  - ~port~ (default: ~#f~)
+
+    Listen on the _integer_ port instead of the default port of 25.
+
+  - ~proxy-v2~ (default: ~#f~)
+
+    If ~#t~, then support the PROXYv2 protocol, rewriting appropriately source
+    address received from proxy.
+
+  - ~received-auth~ (default: ~#f~)
+
+    If ~#t~, then in “Received” headers, report whether the session was
+    authenticated and by which local user.
+
+  - ~senders~ (default: ~#f~)
+
+    Look up the authenticated user in the supplied
+    ~<opensmtpd-table-configuration>~ to find the email addresses that user is
+    allowed to submit mail as.
+
+  - ~secure-connection~ (default: ~#f~)
+
+    This is a string of one of these options:
+
+    |----------------------+---------------------------------------------|
+    | "smtps"              | Support SMTPS, by default on port 465.      |
+    |----------------------+---------------------------------------------|
+    | "tls"                | Support STARTTLS, by default on port 25.    |
+    |----------------------+---------------------------------------------|
+    | "tls-require-verify" | Like tls, but force clients to establish    |
+    |                      | a secure connection before being allowed to |
+    |                      | start an SMTP transaction.  With the verify |
+    |                      | option, clients must also provide a valid   |
+    |                      | certificate to establish an SMTP session.   |
+    |----------------------+---------------------------------------------|
+
+  - ~tag~ (default: ~#f~)
+
+    Clients connecting to the listener are tagged with the given string tag.
+
+- Data Type: opensmtpd-listen-on-socket-configuration
+
+  Data type representing the configuration of an
+  ~<opensmtpd-listen-on-socket-configuration>~. Listen for incoming SMTP
+  connections on the Unix domain socket =/var/run/smtpd.sock=. This is done by
+  default, even if the directive is absent.
+
+  - ~filters~ (default: ~#f~)
+
+    A list of one or many ~<opensmtpd-filter-configuration>~ or
+    ~<opensmtpd-filter-phase-configuration>~ records. These filter incoming
+    connections handled by this listener.
+
+  - ~mask-src~ (default: ~#f~)
+
+    If ~#t~, then omit the from part when prepending “Received” headers.
+
+  - ~tag~ (default: ~#f~)
+
+    Clients connecting to the listener are tagged with the given string tag.
+
+- Data Type: opensmtpd-match-configuration
+
+  This data type represents the configuration of an
+  ~<opensmtpd-match-configuration>~ record.
+
+  If at least one mail envelope matches the options of one match record, receive
+  the incoming message, put a copy into each matching envelope, and atomically
+  save the envelopes to the mail spool for later processing by the respective
+  ~<opensmtpd-action-configuration>~ found in fieldname ~action~.
+
+  - ~action~ (default: ~#f~)
+
+    If mail matches this match configuration, then do this action. Valid values
+    include ~<opensmtpd-action-local-delivery-configuration>~ or
+    ~<opensmtpd-action-relay-configuration>~.
+
+  - ~options~ (default: ~#f~) ~<opensmtpd-option-configuration>~
+    The fieldname 'option' is a list of unique
+    ~<opensmtpd-option-configuration>~ records.
+
+    Each ~<opensmtpd-option-configuration>~ record's fieldname 'option' has some
+    mutually exclusive options: there can be one "for" and one "from" option.
+
+    |---------------------------+--------------------------------|
+    | for                       | from                           |
+    |---------------------------+--------------------------------|
+    | use one of the following: | only use one of the following: |
+    |---------------------------+--------------------------------|
+    | "for any"                 | "from any"                     |
+    | "for local"               | "from auth"                    |
+    | "for domain"              | "from local"                   |
+    | "for rcpt-to"             | "from mail-from"               |
+    |                           | "from socket"                  |
+    |                           | "from src"                     |
+    |---------------------------+--------------------------------|
+
+    The following matching options are supported and can all be negated via (not
+    #t). The options that support a table (anything surrounded with '<' and '>'
+    eg: <table>), also support specifying regex via (regex #t).
+
+    - =for any=
+
+        Specify that session may address any destination.
+
+    - =for local=
+
+        Specify that session may address any local domain.  This is the default,
+        and may be omitted.
+
+    - =for domain _domain_ | <domain>=
+
+        Specify that session may address the string or list table _domain_.
+
+    - =for rcpt-to _recipient_ | <recipient>=
+
+        Specify that session may address the string or list table _recipient_.
+
+    - =from any=
+
+        Specify that session may originate from any source.
+
+    - =from auth=
+
+        Specify that session may originate from any authenticated user, no matter
+        the source IP address.
+
+    - =from auth _user_ | <user>=
+
+        Specify that session may originate from authenticated _user_ or user list
+        user, no matter the source IP address.
+
+    - =from local=
+
+        Specify that session may only originate from a local IP address, or from
+        the local enqueuer.  This is the default, and may be omitted.
+
+    - =from mail-from _sender_ | <sender>=
+
+        Specify that session may originate from _sender_ or table _sender_, no
+        matter the source IP address.
+
+    - =from rdns=
+
+        Specify that session may only originate from an IP address that resolves
+        to a reverse DNS.
+
+    - =from rdns _hostname_ | <hostname>=
+
+        Specify that session may only originate from an IP address that resolves
+        to a reverse DNS matching string or list string _hostname_.
+
+    - =from socket=
+
+        Specify that session may only originate from the local enqueuer.
+
+    - =from src _address_ | <address>=
+
+        Specify that session may only originate from string or list table address
+        which can be a specific _address_ or a subnet expressed in CIDR-notation.
+
+    - =auth=
+
+      Matches transactions which have been authenticated.
+
+    - =auth _username_ | <username>=
+
+      Matches transactions which have been authenticated for user or user list
+      _username_.
+
+    - =helo _helo-name_ | <helo-name>=
+
+      Specify that session's HELO / EHLO should match the string or list table
+      _helo-name_.
+
+    - =mail-from _sender_ | <sender>=
+
+      Specify that transactions's MAIL FROM should match the string or list
+      table _sender_.
+
+    - =rcpt-to _recipient_ | <recipient>=
+
+      Specify that transaction's RCPT TO should match the string or list table
+      _recipient_.
+
+    - =tag tag=
+         Matches transactions tagged with the given _tag_.
+
+    - =tls=
+         Specify that transaction should take place in a TLS channel.
+
+    Here is a simple example:
+    #+BEGIN_SRC scheme
+    (opensmtpd-option-configuration
+     (not #t)
+     (regex #f)
+     (option "for domain")
+     (data (opensmtpd-table-configuration
+            (name "domain-table")
+            (data (list "gnu.org" "dismail.de")))))
+    #+END_SRC
+
+    The mail must NOT come from the domains =gnu.org= or =dismail.de=.
+
+  - Data Type: opensmtpd-option-configuration
+
+- Data Type: opensmtpd-action-local-delivery-configuration
+
+  This data type represents the configuration of an
+  ~<opensmtpd-action-local-delivery-configuration>~ record.
+
+  - ~name~ (default: ~#f~)
+
+    ~name~ is the string name of the relay action.
+
+  - ~method~ (default: ~"mbox"~)
+
+    The email delivery option.  Valid options are:
+
+    - ~"mbox"~
+
+      Deliver the message to the user's mbox with mail.local(8).
+
+    - ~"expand-only"~
+
+      Only accept the message if a delivery method was specified in an aliases
+      or _.forward file_.
+
+    - ~"forward-only"~
+
+      Only accept the message if the recipient results in a remote address after
+      the processing of aliases or forward file.
+
+    - ~<opensmtpd-lmtp-configuration>~
+
+      Deliver the message to an LMTP server at
+      ~<opensmtpd-lmtp-configuration>~'s fieldname ~destination~. The location
+      may be expressed as string host:port or as a UNIX socket. Optionally,
+      ~<opensmtpd-lmtp-configuration>~'s fieldname ~rcpt-to~ might be specified
+      to use the recipient email address (after expansion) instead of the local
+      user in the LMTP session as RCPT TO.
+
+    - ~<opensmtpd-maildir-configuration>~
+
+      Deliver the message to the maildir in
+      ~<opensmtpd-maildir-configuration>~'s fieldname ~pathname~ if specified,
+      or by default to =~/Maildir=.
+
+      The pathname may contain format specifiers that are expanded before use
+      (see the below section about Format Specifiers).
+
+      If ~<opensmtpd-maildir-configuration>~'s record fieldname ~junk~ is ~#t~,
+      then message will be moved to the ‘Junk’ folder if it contains a positive
+      ‘X-Spam’ header. This folder will be created under fieldname ~pathname~ if
+      it does not yet exist.
+
+    - ~<opensmtpd-mda-configuration>~
+
+      Delegate the delivery to the ~<opensmtpd-mda-configuration>~'s fieldname
+      ~command~ (type string) that receives the message on its standard input.
+
+      The ~command~ may contain format specifiers that are expanded before use
+      (see Format Specifiers).
+
+  - ~alias~ (default: ~#f~)
+
+    Use the mapping table for aliases expansion. ~alias~ is an
+    ~<opensmtpd-table-configuration>~.
+
+  - ~ttl~ (default: ~#f~)
+
+    ~ttl~ is a string specify how long a message may remain in the queue.  It's
+    format is =n{s|m|h|d}=.  eg: "4m" is four minutes.
+
+  - ~user~ (default: ~#f~ )
+
+    ~user~ is the string username for performing the delivery, to be looked up
+    with getpwnam(3).
+
+    This is used for virtual hosting where a single username is in charge of
+    handling delivery for all virtual users.
+
+    This option is not usable with the mbox delivery method.
+
+  - ~userbase~ (default: ~#f~)
+
+    ~userbase~ is an ~<opensmtpd-table-configuration>~ record for mapping user
+    lookups instead of the getpwnam(3) function.
+
+    The fieldnames ~user~ and ~userbase~ are mutually exclusive.
+
+  - ~virtual~ (default: ~#f~)
+
+    ~virtual~ is an ~<opensmtpd-table-configuration>~ record is used for virtual
+    expansion.
+    # TODO man 5 smtpd.conf says "The aliasing table format is described in
+    # table(5)." What is virtual expansion? I do NOT know how to use ~virtual~
+    # properly. What sort of <opensmtpd-table-configuration> do I need? does the
+    # below work?
+    # (opensmtpd-table (name "virtual") (data '(("joshua" . "jbranso@dismail.de"))))
+
+  # TODO fix this ~wrapper documentation~.  Should it accept an
+  # <opensmtpd-mda-configuration> ?  If so, then I need to write an <opensmtpd-mda-configuration>
+  # - ~wrapper~ (default: )
+
+  # TODO double check that these options are all correct
+
+- Data Type: opensmtpd-action-relay-configuration
+
+   This data type represents the configuration of an
+   ~<opensmtpd-action-relay-configuration>~ record.
+
+  - ~name~ (default: ~#f~)
+
+    ~name~ is the string name of the relay action.
+
+  - ~backup~ (default: ~#f~)
+
+    When ~#t~, operate as a backup mail exchanger delivering messages to any
+    mail exchanger with higher priority.
+
+  - ~backup-mx~ (default: ~#f~)
+
+    Operate as a backup mail exchanger delivering messages to any mail exchanger
+    with higher priority than mail exchanger identified as string name.
+
+  - ~helo~ (default: ~#f~)
+
+    Advertise string heloname as the hostname to other mail exchangers during
+    the HELO phase.
+
+  - ~helo-src~ (default: ~#f~ )
+
+     Use the mapping ~<openmstpd-table-configuration>~ to look up a hostname
+    matching the source address, to advertise during the HELO phase.
+
+  - ~domain~ (default: ~#f~)
+
+    Do not perform MX lookups but look up destination domain in an
+    ~<opensmtpd-table-configuration>~ and use matching relay url as relay host.
+
+  - ~host~ (default: ~#f~)
+
+    Do not perform MX lookups but relay messages to the relay host described by
+    the string relay-url. The format for relay-url is
+    =[proto://[label@]]host[:port]=. The following protocols are available:
+
+     |------------+----------------------------------------------------------------|
+     | smtp       | Normal SMTP session with opportunistic STARTTLS (the default). |
+     | smtp+tls   | Normal SMTP session with mandatory STARTTLS.                   |
+     | smtp+notls | Plain text SMTP session without TLS.                           |
+     | lmtp       | LMTP session.  port is required.                               |
+     | smtps      | SMTP session with forced TLS on connection, default port is    |
+     |            | 465.                                                           |
+     |------------+----------------------------------------------------------------|
+
+    Unless noted, port defaults to 25.
+
+    The label corresponds to an entry in a credentials table, as documented in
+    =table(5)=. It is used with the ="smtp+tls"= and ="smtps"= protocols for
+    authentication. Server certificates for those protocols are verified by
+    default.
+
+  - ~pki~ (default: ~#f~)
+
+    For secure connections, use the certificate associated with
+    ~<opensmtpd-pki-configuration>~ (declared in a pki directive) to prove the
+    client's identity to the remote mail server.
+
+  - ~srs~ (default: ~#f~)
+
+    If ~#t~, then when relaying a mail resulting from a forward, use the Sender
+    Rewriting Scheme to rewrite sender address.
+
+  - ~tls~ (default: ~#f~) boolean or string "no-verify"
+
+    When ~#t~, Require TLS to be used when relaying, using mandatory STARTTLS by
+    default. When used with a smarthost, the protocol must not be
+    ="smtp+notls://"=. When string ~"no-verify"~, then do not require a valid
+    certificate.
+
+  - ~auth~ (default: ~#f~) ~<opensmtpd-table-configuration>~
+
+    Use the alist ~<opensmtpd-table-configuration>~ for connecting to relay-url
+    using credentials. This option is usable only with fieldname ~host~ option.
+
+  - ~mail-from~ (default: ~#f~) string
+
+    Use the string _mailaddress_ as MAIL FROM address within the SMTP transaction.
+
+  - ~src~ (default: ~#f~) string | ~<opensmtpd-table-configuration>~
+
+    Use the string or ~<opensmtpd-table-configuration>~ sourceaddr for the
+    source IP address, which is useful on machines with multiple interfaces. If
+    the list contains more than one address, all of them are used in such a way
+    that traffic is routed as efficiently as possible.
+
+- Data Type: opensmtpd-filter-configuration
+
+   This data type represents the configuration of an
+   ~<opensmtpd-filter-configuration>~. This is the filter record one should use
+   if they want to use an external package to filter email eg: rspamd or
+   spamassassin.
+
+  - ~name~ (default: ~#f~)
+
+    The string name of the filter.
+
+  - ~proc~ (default: ~#f~)
+
+    # TODO let ~proc~ be a gexp
+    The string command or process name.  If ~proc-exec~ is ~#t~, ~proc~ is
+    treated as a command to execute.  Otherwise, it is a process name.
+
+  - ~proc-exec~ (default: ~#f~)
+
+- Data Type: opensmtpd-filter-phase-configuration
+
+   This data type represents the configuration of an
+   ~<opensmtpd-filter-phase-configuration>~.
+
+   In a regular workflow, smtpd(8) may accept or reject a message based only on
+   the content of envelopes. Its decisions are about the handling of the message,
+   not about the handling of an active session.
+
+   Filtering extends the decision making process by allowing smtpd(8) to stop at
+   each phase of an SMTP session, check that options are met, then decide if a
+   session is allowed to move forward.
+
+   With filtering via an ~<opensmtpd-filter-phase-configuration>~ record, a
+   session may be interrupted at any phase before an envelope is complete. A
+   message may also be rejected after being submitted, regardless of whether the
+   envelope was accepted or not.
+
+  - ~name~ (default: ~#f~)
+
+    The string name of the filter phase.
+
+  - ~phase-name~ (default: ~#f~)
+
+    The string name of the phase. Valid values are:
+
+   |-------------+-----------------------------------------------|
+   | "connect"   | upon connection, before a banner is displayed |
+   |-------------+-----------------------------------------------|
+   | "helo"      | after HELO command is submitted               |
+   |-------------+-----------------------------------------------|
+   | "ehlo"      | after EHLO command is submitted               |
+   |-------------+-----------------------------------------------|
+   | "mail-from" | after MAIL FROM command is submitted          |
+   |-------------+-----------------------------------------------|
+   | "rcpt-to"   | after RCPT TO command is submitted            |
+   |-------------+-----------------------------------------------|
+   | "data"      | after DATA command is submitted               |
+   |-------------+-----------------------------------------------|
+   | "commit"    | after message is fully is submitted           |
+   |-------------+-----------------------------------------------|
+
+  - ~options~ (default ~#f~)
+
+    A list of unique ~<opensmtpd-option-configuration>~ records.
+
+    At each phase, various options, specified by a list of
+    ~<opensmtpd-option-configuration>~, may be checked. The
+    ~<opensmtpd-option-configuration>~'s fieldname 'option' values of: "fcrdns",
+    "rdns", and "src" data are available in all phases, but other data must have
+    been already submitted before they are available. Options with a =<table>=
+    next to them require the ~<opensmtpd-option-configuration>~'s fieldname
+    ~data~ to be an ~<opensmtpd-table-configuration>~. There are the available
+    options:
+
+    |-------------------+----------------------------------------|
+    | fcrdns            | forward-confirmed reverse DNS is valid |
+    |-------------------+----------------------------------------|
+    | rdns              | session has a reverse DNS              |
+    |-------------------+----------------------------------------|
+    | rdns <table>      | session has a reverse DNS in table     |
+    |-------------------+----------------------------------------|
+    | src <table>       | source address is in table             |
+    |-------------------+----------------------------------------|
+    | helo <table>      | helo name is in table                  |
+    |-------------------+----------------------------------------|
+    | auth              | session is authenticated               |
+    |-------------------+----------------------------------------|
+    | auth <table>      | session username is in table           |
+    |-------------------+----------------------------------------|
+    | mail-from <table> | sender address is in table             |
+    |-------------------+----------------------------------------|
+    | rcpt-to <table>   | recipient address is in table          |
+    |-------------------+----------------------------------------|
+
+    These conditions may all be negated by setting
+    ~<opensmtpd-option-configuration>~'s fieldname ~not~ to ~#t~.
+
+    Any conditions that require a table may indicate that tables include regexs
+    setting ~<opensmtpd-option-configuration>~'s fieldname ~regex~ to ~#t~.
+
+  - ~decision~
+
+    A string decision to be taken. Some decisions require an ~message~ or
+    ~value~. Valid strings are:
+
+   |----------------------+------------------------------------------------|
+   | "bypass"             | the session or transaction bypasses filters    |
+   |----------------------+------------------------------------------------|
+   | "disconnect" message | the session is disconnected with message       |
+   |----------------------+------------------------------------------------|
+   | "junk"               | the session or transaction is junked, i.e., an |
+   |                      | ‘X-Spam: yes’ header is added to any messages  |
+   |----------------------+------------------------------------------------|
+   | "reject" message     | the command is rejected with message           |
+   |----------------------+------------------------------------------------|
+   | "rewrite" value      | the command parameter is rewritten with value  |
+   |----------------------+------------------------------------------------|
+
+    Decisions that involve a message require that the message be RFC valid,
+    meaning that they should either start with a 4xx or 5xx status code.
+    Descisions can be taken at any phase, though junking can only happen before
+    a message is committed.
+
+  - ~message~ (default ~#f~)
+
+    A string message beginning with a 4xx or 5xx status code.
+
+  - ~value~ (default: ~#f~)
+
+   A number value.  ~value~ and ~message~ are mutually exclusive.
+
+- Data Type: opensmtpd-option-configuration
+
+  This data type represents the configuration of an
+  ~<opensmtpd-option-configuration>~, which is used by
+  ~<opensmtpd-filter-phase-configuration>~ and ~<opensmtpd-match-configuration>~
+  to match various options for email.
+
+  - ~conditition~ (default ~#f~)
+
+    A string option to be taken. Some options require a string or an
+    ~<opensmtpd-table-configuration>~ via the fieldname data. When the option
+    record is used inside of an ~<opensmtpd-filter-phase-configuration>~, then
+    valid strings are:
+
+    At each phase, various options may be matched. The fcrdns, rdns, and src
+    data are available in all phases, but other data must have been already
+    submitted before they are available.
+
+    |---------------------+----------------------------------------|
+    | "fcrdns"            | forward-confirmed reverse DNS is valid |
+    | "rdns"              | session has a reverse DNS              |
+    | "rdns" <table>      | session has a reverse DNS in table     |
+    | "src" <table>       | source address is in table             |
+    | "helo" <table>      | helo name is in table                  |
+    | "auth"              | session is authenticated               |
+    | "auth" <table>      | session username is in table           |
+    | "mail-from" <table> | sender address is in table             |
+    | "rcpt-to" <table>   | recipient address is in table          |
+    |---------------------+----------------------------------------|
+
+    When ~<opensmtpd-option-configuration>~ is used inside of an
+    ~<opensmtpd-match-configuration>~, then valid strigs for fieldname ~option~
+    are: "for", "for any", "for local", "for domain", "for rcpt-to", "from any"
+    "from auth", "from local", "from mail-from", "from rdns", "from socket",
+    "from src", "auth", "helo", "mail-from", "rcpt-to", "tag", or "tls".
+
+  - ~data~ (default ~#f~) ~<opensmtpd-table-configuration>~
+
+    Some options require a table to be present. One would specify that table
+    here.
+  - ~regex~ (default: ~#f~) boolean
+
+    Any options using a table may indicate that tables hold regex by
+    prefixing the table name with the keyword regex.
+  - ~not~ (default: ~#f~) boolean
+
+    When ~#t~, this option record is negated.
+
+- Data Type: opensmtpd-table-configuration
+
+  This data type represents the configuration of an
+  ~<opensmtpd-table-configuration>~.
+
+  - ~name~ (default ~#f~)
+
+    ~name~ is the name of the ~<opensmtpd-table-configuration>~ record.
+
+  - ~data~ (default: ~#f~)
+
+    ~data~ expects a list of strings or an alist, which is a list of
+    cons cells.  eg: ~(data (list ("james" . "password")))~ OR
+    ~(data (list ("gnu.org" "fsf.org")))~.
+
+- Data Type: opensmtpd-pki-configuration
+
+  This data type represents the configuration of an
+  ~<opensmtpd-pki-configuration>~.
+
+  - ~domain~ (default ~#f~)
+
+    ~domain~ is the string name of the ~<opensmtpd-pki-configuration>~ record.
+
+  - ~cert~ (default: ~#f~)
+
+    ~cert~ (default: ~#f~)
+
+    ~cert~ is the string certificate filename to use for this pki.
+
+  - ~key~ (default: ~#f~)
+
+    ~key~ is the string certificate falename to use for this pki.
+
+  - ~dhe~ (default: ~"none"~)
+
+    Specify the DHE string parameter to use for DHE cipher suites with host
+    pkiname. Valid parameter values are "none", "legacy", or "auto". For "legacy", a
+    fixed key length of 1024 bits is used, whereas for "auto", the key length is
+    determined automatically. The default is "none", which disables DHE cipher
+    suites.
+
+- Data Type: opensmtpd-maildir-configuration
+
+  - ~pathname~ (default: ~"~/Maildir"~)
+
+    Deliver the message to the maildir if pathname if specified, or by default
+    to =~/Maildir=.
+
+    The pathname may contain format specifiers that are expanded before use
+    (see FORMAT SPECIFIERS).
+
+  - ~junk~ (default: ~#f~)
+
+    If the junk argument is ~#t~, then the message will be moved to the =‘Junk’=
+    folder if it contains a positive =‘X-Spam’= header. This folder will be
+    created under pathname if it does not yet exist.
+
+- Data Type: opensmtpd-mda-configuration
+  # Do we need a dataypte for mda configuration?
+  # this could just be a gexp in the fieldname opensmtpd-configuration-mda
+
+  - ~name~
+
+    The string name for this MDA command.
+
+  - ~command~
+
+    Delegate the delivery to a command that receives the message on its standard
+    input.
+
+    The command may contain format specifiers that are expanded before use (see
+    FORMAT SPECIFIERS).
+
+- Data Type: opensmtpd-queue-configuration
+
+  - ~compression~ (default ~#f~)
+
+    Store queue files in a compressed format. This may be useful to save disk
+    space.
+  - ~encryption~ (default ~#f~)
+
+    Encrypt queue files with EVP_aes_256_gcm(3). If no key is specified, it is
+    read with getpass(3). If the string stdin or a single dash (‘-’) is given
+    instead of a key, the key is read from the standard input.
+  - ~ttl-delay~ (default ~#f~)
+
+    Set the default expiration time for temporarily undeliverable messages,
+    given as a positive decimal integer followed by a unit s, m, h, or d. The
+    default is four days ("4d").
+
+- Data Type: opensmtpd-smtp-configuration
+
+  Data type representing an ~<opensmtpd-smtp-configuration>~ record.
+
+  - ~ciphers~ (default: ~#f~)
+
+    Set the control string for SSL_CTX_set_cipher_list(3).  The default is
+             "HIGH:!aNULL:!MD5".
+  - ~limit-max-mails~ (default: ~100~)
+
+    Limit the number of messages to count for each sessio
+  - ~limit-max-rcpt~ (default: ~1000~)
+
+    Limit the number of recipients to count for each transaction.
+  - ~max-message-size~ (default: ~35M~)
+
+    Reject messages larger than size, given as a positive number of bytes or as
+    a string to be parsed with scan_scaled(3).
+  - ~sub-addr-delim character~ (default: ~+~)
+
+    When resolving the local part of a local email address, ignore the ASCII
+    character and all characters following it. This is helpful for email
+    filters. ="admin+bills@gnu.org"= is the same email address as
+    ="admin@gnu.org"=. BUT an email filter can filter emails addressed to first
+    email address into a 'Bills' email folder.
+
+- Data Type: opensmtpd-srs-configuration
+
+  - ~key~ (default: ~#f~)
+
+     Set the secret key to use for SRS, the Sender Rewriting Scheme.
+
+  - ~backup-key~ (default: ~#f~)
+
+    Set a backup secret key to use as a fallback for SRS. This can be used to
+    implement SRS key rotation.
+  - ~ttl-delay~ (default: ~"4d"~)
+
+    Set the time-to-live delay for SRS envelopes. After this delay, a bounce
+    reply to the SRS address will be discarded to limit risks of forged
+    addresses.
+
+- Format Specifiers
+
+  Some configuration records support expansion of their parameters at
+  runtime. Such records (for example
+  ~<opensmtpd-maildir-configuration>~, ~<opensmtpd-mda-configuration>~) may use
+  format specifiers which are expanded before delivery or relaying. The
+  following formats are currently supported:
+
+    |---------------------+-------------------------------------------------------|
+    | =%{sender}=         | sender email address, may be empty string             |
+    | =%{sender.user}=    | user part of the sender email address, may be empty   |
+    | =%{sender.domain}=  | domain part of the sender email address, may be empty |
+    | =%{rcpt}=           | recipient email address                               |
+    | =%{rcpt.user}=      | user part of the recipient email address              |
+    | =%{rcpt.domain}=    | domain part of the recipient email address            |
+    | =%{dest}=           | recipient email address after expansion               |
+    | =%{dest.user}=      | user part after expansion                             |
+    | =%{dest.domain}=    | domain part after expansion                           |
+    | =%{user.username}=  | local user                                            |
+    | =%{user.directory}= | home directory of the local user                      |
+    | =%{mbox.from}=      | name used in mbox From separator lines                |
+    | =%{mda}=            | mda command, only available for mda wrappers          |
+    |---------------------+-------------------------------------------------------|
+
+  Expansion formats also support partial expansion using the optional bracket notations
+  with substring offset.  For example, with recipient domain =“example.org”=:
+
+    |------------------------+----------------------|
+    | =%{rcpt.domain[0]}=    | expands to “e”       |
+    | =%{rcpt.domain[1]}=    | expands to “x”       |
+    | =%{rcpt.domain[8:]}=   | expands to “org”     |
+    | =%{rcpt.domain[-3:]}=  | expands to “org”     |
+    | =%{rcpt.domain[0:6]}=  | expands to “example” |
+    | =%{rcpt.domain[0:-4]}= | expands to “example” |
+    |------------------------+----------------------|
+
+  In addition, modifiers may be applied to the token.  For example, with recipient
+  =“User+Tag@Example.org”=:
+
+    |--------------------------+-----------------------------------|
+    | =%{rcpt:lowercase}=      | expands to “user+tag@example.org” |
+    | =%{rcpt:uppercase}=      | expands to “USER+TAG@EXAMPLE.ORG” |
+    | =%{rcpt:strip}=          | expands to “User@Example.org”     |
+    | =%{rcpt:lowercasestrip}= | expands to “user@example.org”     |
+    |--------------------------+-----------------------------------|
+
+  For security concerns, expanded values are sanitized and potentially dangerous
+  characters are replaced with ‘:’. In situations where they are desirable, the
+  “raw” modifier may be applied. For example, with recipient
+  =“user+t?g@example.org”=:
+
+    |---------------+-----------------------------------|
+    | =%{rcpt}=     | expands to “user+t:g@example.org” |
+    | =%{rcpt:raw}= | expands to “user+t?g@example.org” |
+    |---------------+-----------------------------------|
+*** some example ~<opensmtpd-configurations>~ that are probably out of date
+
+      #+BEGIN_SRC scheme
+
+;;this works! (opensmtpd-configuration->mixed-text-file (opensmtpd-configuration (smtp (opensmtpd-smtp-configuration (limit-max-rcpt 10)))))
+
+;; (tables (list
+;;          (opensmtpd-table-configuration
+;;           (name "aliases")
+;;           (data
+;;            (list
+;;             (cons "webmaster" "root")
+;;             (cons "postmaster" "root")
+;;             (cons "abuse" "root"))))
+;;
+;;          (opensmtpd-table-configuration
+;;           (name "vdoms")
+;;           (data (list "gnucode.me"
+;;                         "gnu-hurd.com")))
+;;          (opensmtpd-table-configuration
+;;           (name (opensmtpd-table-configuration
+;;                   (name "virtual")
+;;                   (data (list "root" "postmaster@gnu.org"))))
+;;           (data (list (cons "joshua@gnucode.me" "joshua")
+;;                         (cons "jbranso@gnucode.me" "joshua")
+;;                         (cons "postmaster@gnucode.me" "joshua"))))))
+
+            ;; (filter-chains
+            ;;  (list
+            ;;   (opensmtpd-filter-chain
+            ;;    (name "dropDumbEmails")
+            ;;    (filter-names (list "nofcrdnsDisconnect"
+            ;;                        "nordnsDisconnect")))))
+            ;; (filter-phases
+            ;;  (list (opensmtpd-filter-phase-configuration
+            ;;         (name "nofcrdnsDisconnect")
+            ;;         (phase-name "connect")
+            ;;         (options (list "!fcrdns"))
+            ;;         (decision "disconnect")
+            ;;         (message "You have not set up forward confirmed DNS."))
+            ;;        (opensmtpd-filter-phase-configuration
+            ;;         (name "nordnsDisconnect")
+            ;;         (phase-name "connect")
+            ;;         (options (list "!rdns"))
+            ;;
+            ;;         (decision "reject")
+            ;;         (message "You have not set up reverse DNS."))))
+            ;;
+(define example-opensmtpd-config-smaller
+  (opensmtpd-configuration
+   (listen-ons
+    (list
+     ;; this forum help suggests that I listen on 0.0.0.0 and NOT eth0
+     ;; https://serverfault.com/questions/726795/opensmtpd-wont-work-at-reboot
+     ;; this listens for email from the outside world
+     ;; this lets local users logged into the system via ssh send email
+     (opensmtpd-listen-on-configuration
+      (interface "wlp2s0")
+      (port 465))))
+   (matches (list
+             (opensmtpd-match-configuration
+              (name "maildir")
+              (action (opensmtpd-action-local-delivery-configuration
+                       (method (opensmtpd-maildir-configuration
+                                (pathname "/home/%{rcpt.user}/Maildir")
+                                (junk #t)))
+                       (virtual (opensmtpd-table-configuration
+                                 (name "virtual")
+                                 (data (list "root" "james@gnu.org"))))))
+              (for (opensmtpd-option-configuration
+                    (option "for local"))))))))
+
+(define example-opensmtpd-config-small
+  (let ([interface "wlp2s0"]
+        [creds (opensmtpd-table-configuration
+                (name "creds")
+                (data
+                 (list
+                  (cons "joshua"
+                        "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))))]
+        [receive-action (opensmtpd-action-local-delivery-configuration
+                         (name "receive")
+                         (method (opensmtpd-maildir-configuration
+                                  (pathname "/home/%{rcpt.user}/Maildir")
+                                  (junk #t)))
+                         (virtual (opensmtpd-table-configuration
+                                   (name "virtual")
+                                   (data (list "root" "james@gnu.org")))))]
+        [smtp.gnucode.me (opensmtpd-pki-configuration
+                          (domain "smtp.gnucode.me")
+                          (cert "opensmtpd.scm")
+                          (key "opensmtpd.scm"))])
+    (opensmtpd-configuration
+     (listen-ons
+      (list
+       ;; this forum help suggests that I listen on 0.0.0.0 and NOT eth0
+       ;; https://serverfault.com/questions/726795/opensmtpd-wont-work-at-reboot
+       ;; this listens for email from the outside world
+       (opensmtpd-listen-on-configuration
+        (interface interface)
+        (port 25)
+        (secure-connection "tls")
+        (pki smtp.gnucode.me))
+       ;; this lets local users logged into the system via ssh send email
+       (opensmtpd-listen-on-configuration
+        (interface interface)
+        (port 465)
+        (secure-connection "smtps")
+        (pki smtp.gnucode.me)
+        (auth creds))))
+     (matches (list
+               (opensmtpd-match-configuration
+                (action receive-action)
+                (for (opensmtpd-option-configuration
+                      (option "for local")))))))))
+
+(define example-opensmtpd-config
+  (let ([interface "lo"]
+        [creds (opensmtpd-table-configuration
+                (name "creds")
+                (data
+                 (list
+                  (cons "joshua"
+                        "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))))]
+        [receive-action (opensmtpd-action-local-delivery-configuration
+                         (name "receive")
+                         (method (opensmtpd-maildir-configuration
+                                  (pathname "/home/%{rcpt.user}/Maildir")
+                                  (junk #t)))
+                         (virtual (opensmtpd-table-configuration
+                                   (name "virtual")
+                                   (data (list "josh" "jbranso@dismail.de")))))]
+        [smtp.gnucode.me (opensmtpd-pki-configuration
+                          (domain "smtp.gnucode.me")
+                          (cert "opensmtpd.scm")
+                          (key "opensmtpd.scm"))])
+    (opensmtpd-configuration
+     ;; (mta-max-deferred 50)
+     ;; (queue
+     ;;  (opensmtpd-queue-configuration
+     ;;   (compression #t)))
+     ;; (smtp
+     ;;  (opensmtpd-smtp-configuration
+     ;;   (max-message-size "10M")))
+     ;; (srs
+     ;;  (opensmtpd-srs-configuration
+     ;;   (ttl-delay "5d")))
+     (listen-ons
+      (list
+       ;; this forum help suggests that I listen on 0.0.0.0 and NOT eth0
+       ;; https://serverfault.com/questions/726795/opensmtpd-wont-work-at-reboot
+       ;; this listens for email from the outside world
+       (opensmtpd-listen-on-configuration
+        (interface interface)
+        (port 25)
+        (secure-connection "tls")
+        (pki smtp.gnucode.me))
+       ;; this lets local users logged into the system via ssh send email
+       (opensmtpd-listen-on-configuration
+        (interface "lo")
+        (port 25)
+        (secure-connection "tls")
+        (pki smtp.gnucode.me))
+       (opensmtpd-listen-on-configuration
+        (interface interface)
+        (port 465)
+        (secure-connection "smtps")
+        (pki smtp.gnucode.me)
+        (auth creds)
+        ;;(filter )
+        )
+       (opensmtpd-listen-on-configuration
+        (interface interface)
+        (port 587)
+        (secure-connection "tls-require")
+        (pki smtp.gnucode.me)
+        (auth creds))))
+     (matches (list
+               (opensmtpd-match-configuration
+                (action (opensmtpd-action-relay-configuration
+                         (name "send")))
+                (for (opensmtpd-option-configuration
+                      (option "for any")))
+                (from (opensmtpd-option-configuration
+                       (option "from any")))
+                (auth (opensmtpd-option-configuration
+                       (option "auth"))))
+               (opensmtpd-match-configuration
+                (action receive-action)
+                (from (opensmtpd-option-configuration
+                       (option "from any")))
+                (for (opensmtpd-option-configuration
+                      (option "for domain")
+                      (value (list "gnucode.me" "gnu-hurd.com")))))
+               (opensmtpd-match-configuration
+                (action receive-action)
+                (for (opensmtpd-option-configuration
+                      (option "for local")))))))))
+      #+END_SRC
+
+*** some example smtpd.conf configs
+*** serving multiple domains with one pki
+
+source:  https://www.reddit.com/r/openbsd/comments/n41wkz/how_to_host_different_domains_for_an_email_server/
+#+BEGIN_EXAMPLE
+​pki mail.primary.domain cert​pki mail.primary.domain cert "/etc/ssl/mail.primary.domain.fullchain.pem"
+
+pki mail.primary.domain key "/etc/ssl/private/mail.primary.domain.key"
+
+
+filter check_dyndns phase connect match rdns regex { '.*\.dyn\..*', '.*\.dsl\..*' } \
+
+disconnect "550 no residential connections"
+
+
+filter check_rdns phase connect match !rdns \
+
+disconnect "550 no rDNS is so 80s"
+
+
+filter check_fcrdns phase connect match !fcrdns \
+
+disconnect "550 no FCrDNS is so 80s"
+
+
+filter senderscore \
+
+proc-exec "filter-senderscore -blockBelow 10 -junkBelow 70 -slowFactor 5000"
+
+
+filter rspamd proc-exec "filter-rspamd"
+
+
+table usermap file:/etc/mail/usermap
+
+table credentials file:/etc/mail/credentials
+
+table domains { primary.domain, second.domain }
+
+
+listen on all tls pki mail.primary.domain \
+
+filter { check_dyndns, check_rdns, check_fcrdns, senderscore, rspamd }
+
+
+listen on egress port 465 smtps pki mail.primary.domain \
+
+auth ~<credentials>~ filter rspamd
+
+
+action "inbound" lmtp "/var/dovecot/lmtp" rcpt-to virtual ~<usermap>~ #maildir junk alias <aliases>
+
+action "outbound" relay helo mail.primary.domain
+
+
+match from any for domain ~<domains>~ action "inbound"
+
+match for local action "inbound"
+
+
+match from any auth for any action "outbound"
+
+match for any action "outbound" "/etc/ssl/mail.primary.domain.fullchain.pem"
+
+pki mail.primary.domain key "/etc/ssl/private/mail.primary.domain.key"
+
+
+filter check_dyndns phase connect match rdns regex { '.*\.dyn\..*', '.*\.dsl\..*' } \
+
+disconnect "550 no residential connections"
+
+
+filter check_rdns phase connect match !rdns \
+
+disconnect "550 no rDNS is so 80s"
+
+
+filter check_fcrdns phase connect match !fcrdns \
+
+disconnect "550 no FCrDNS is so 80s"
+
+
+filter senderscore \
+
+proc-exec "filter-senderscore -blockBelow 10 -junkBelow 70 -slowFactor 5000"
+
+
+filter rspamd proc-exec "filter-rspamd"
+
+
+table usermap file:/etc/mail/usermap
+
+table credentials file:/etc/mail/credentials
+
+table domains { primary.domain, second.domain }
+
+
+listen on all tls pki mail.primary.domain \
+
+filter { check_dyndns, check_rdns, check_fcrdns, senderscore, rspamd }
+
+
+listen on egress port 465 smtps pki mail.primary.domain \
+
+auth ~<credentials>~ filter rspamd
+
+
+action "inbound" lmtp "/var/dovecot/lmtp" rcpt-to virtual ~<usermap>~ #maildir junk alias <aliases>
+
+action "outbound" relay helo mail.primary.domain
+
+
+match from any for domain ~<domains>~ action "inbound"
+
+match for local action "inbound"
+
+
+match from any auth for any action "outbound"
+
+match for any action "outbound"
+
+#+END_EXAMPLE
+** PROJ nice things to have [0/9]
+*** TODO Should I delete ~<opensmtpd-mda-configuration>~ ? or fieldname 'opensmtpd-configuration-mda-wrapppers'?
+
+~<opensmtpd-action-local-delivery-configuration>~'s fieldname 'method' allows
+for an mda configuration.  BUT instead of an mda-configuration record, you could
+just use a list of strings and/or gexps.
+
+#+BEGIN_EXAMPLE
+ mda wrapper name command
+             Associate command with the mail delivery agent wrapper named name.  When a local
+             delivery specifies a wrapper, the command associated with the wrapper will be ex‐
+             ecuted instead.  The command may contain format specifiers (see FORMAT
+             SPECIFIERS).
+#+END_EXAMPLE
+
+If I choose to NOT delete ~<opensmtpd-mda-configuration>~, then should I delete
+'opensmtpd-configuration-mda-wrapppers'?
+
+Also should I delete the opensmtpd-action-local-delivery-configuration-wrapper?
+
+*** TODO make the 'auth-optional' and 'auth' fieldnames for ~<opensmtpd-listen-on-configuration>~ autoencrypt passwords. [0/0]
+Guix makes it pretty hard to find the openbsd binary file that encrypts
+passwords for you.  If I can progmatically find this file, it would be nice to
+autoencrypt the users's passwords for you.
+
+What does this mean practically?
+
+#+BEGIN_SRC scheme
+(opensmtpd-table-configuration
+ (name "credentials")
+ (data '(("joshua@gnu.org" . "somePassword")
+           ("postmaster@gnu.org") . "anotherSillyPassword")))
+#+END_SRC
+
+Gets stored in /gnu/store/ in the =smtpd.conf= as something like:
+
+#+BEGIN_EXAMPLE
+table credentials { joshua@gnu.org = $some$Long$EncrytpedPassword, \
+                    postmaster@gnu.org = $some$Long$Other$EncrytpedPassword }
+#+END_EXAMPLE
+
+You would need to encourage users NOT to have passwords in a public git repo.
+With guile-git, it might be possible to sanitize the config, to ensure that the
+passwords are NOT stored in the git repo.
+
+Alternatively, we could put the following in the documentation:
+
+#+BEGIN_SRC scheme
+(use-modules (passwords))
+
+(opensmtpd-table-configuration
+ (name "credentials")
+ (data %passwords))
+#+END_SRC
+
+*** PROJ Why does (opensmtpd-configuration) take so long to initialize? [0/1]
+
+For example, try to initialize this bit of code.  It takes almost 5 seconds.
+#+BEGIN_SRC scheme
+(let ([interface "lo"]
+               [creds-table (opensmtpd-table-configuration
+                             (name "creds")
+                             (data
+                              (list
+                               (cons "joshua"
+                                     "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))))]
+               [receive-action (opensmtpd-action-local-delivery-configuration
+                                (name "receive")
+                                (method (opensmtpd-maildir-configuration
+                                         (pathname "/home/%{rcpt.user}/Maildir")
+                                         (junk #t)))
+                                (virtual (opensmtpd-table-configuration
+                                          (name "virtual")
+                                          (data (list "josh" "jbranso@dismail.de")))))]
+               [filter-dkimsign (opensmtpd-filter
+                                 (name "dkimsign")
+                                 (exec #t)
+                                 (proc (string-append "/path/to/dkimsign  -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                                                      "/path/to/dkimsign-key user nobody group nobody")))]
+               [smtp.gnucode.me (opensmtpd-pki-configuration
+                                 (domain "smtp.gnucode.me")
+                                 (cert "opensmtpd.scm")
+                                 (key "opensmtpd.scm"))])
+           (opensmtpd-configuration
+            (mta-max-deferred 50)
+            (queue
+             (opensmtpd-queue-configuration
+              (compression #t)))
+            (smtp
+             (opensmtpd-smtp-configuration
+              (max-message-size "10M")))
+            (srs
+             (opensmtpd-srs-configuration
+              (ttl-delay "5d")))
+            (listen-ons
+             (list
+              (opensmtpd-listen-on-configuration
+               (interface interface)
+               (port 25)
+               (secure-connection "tls")
+               (filters (list (opensmtpd-filter-phase-configuration
+                               (name "noFRDNS")
+                               (phase "commit")
+                               (options (list (opensmtpd-option-configuration
+                                                  (option "fcrdns")
+                                                  (not #t))))
+                               (decision "disconnect")
+                               (message "No FCRDNS"))))
+               (pki smtp.gnucode.me))
+              ;; this lets local users logged into the system via ssh send email
+              (opensmtpd-listen-on-configuration
+               (interface interface)
+               (port 465)
+               (secure-connection "smtps")
+               (pki smtp.gnucode.me)
+               (auth creds-table)
+               (filters (list filter-dkimsign)))
+              (opensmtpd-listen-on-configuration
+               (interface interface)
+               (port 587)
+               (secure-connection "tls-require")
+               (pki smtp.gnucode.me)
+               (auth creds-table)
+               (filters (list filter-dkimsign)))))
+            (matches (list
+                      (opensmtpd-match-configuration
+                       (action (opensmtpd-action-relay-configuration
+                                (name "relay")))
+                       (for (opensmtpd-option-configuration
+                             (option "for any")))
+                       (from (opensmtpd-option-configuration
+                              (option "from any")))
+                       (auth (opensmtpd-option-configuration
+                              (option "auth"))))
+                      (opensmtpd-match-configuration
+                       (action receive-action)
+                       (from (opensmtpd-option-configuration
+                              (option "from any")))
+                       (for (opensmtpd-option-configuration
+                             (option "for domain")
+                             (value (opensmtpd-table-configuration
+                                     (name "domain-table")
+                                     (data (list "gnucode.me" "gnu-hurd.com")))))))
+                      (opensmtpd-match-configuration
+                       (action receive-action)
+                       (for (opensmtpd-option-configuration
+                             (option "for local"))))))))
+#+END_SRC
+**** TODO one area to look for speed up improvements would be in the sanitize function of =(opensmtpd-listen-on-configuration-filters)=.
+*** PROJ check the code base for places to use apply, map, fold, eval, or remove [3/4]
+
+**** DONE string-in-list would be a good place. maybe is-value-right-type
+
+#+BEGIN_SRC scheme
+(define (string-in-list? string list)
+  (if (null? list)
+      #f
+      (if (and (string? (car list)) (string=? string (car list)))
+          #t
+          (string-in-list? string (cdr list)))))
+
+(define (string-in-list? string list)
+  (primitive-eval (cons 'or (map (lambda (var) (string=? string var)) list))))
+
+#+END_SRC
+
+**** DONE contains-duplicate
+#+BEGIN_SRC scheme
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+       ;;<check whether (first list) is in (rest list)>
+       (let loop ([list (cdr list)]
+                  [1st (car list)])
+         (if (null? list)
+             #f
+             (if (equal? 1st (car list))
+                 (data #t 1st)
+                 (loop (cdr list) 1st))))
+       ;;<check where (rest list) contains a duplicate>
+       (contains-duplicate? (cdr list)))))
+
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or (primitive-eval (cons 'or     ; check if (car list) is in (cdr list)
+                                (map (lambda (var) (equal? var (car list)))
+                                     (cdr list))))
+          ;; check if (cdr list) contains duplicate
+          (contains-duplicate? (cdr list)))))
+#+END_SRC
+
+**** DONE using remove and flatten and map
+#+BEGIN_SRC scheme
+(define (get-opensmtpd-table-configurations value)
+  (delete-duplicates
+   (let loop ([list (flatten
+                     (cond ((opensmtpd-table-configuration? value)
+                            value)
+                           ((record? value)
+                            (let* ([<record-type> (record-type-descriptor value)]
+                                   [list-of-record-fieldnames (record-type-fields <record-type>)])
+                              (map (lambda (fieldname)
+                                     (get-opensmtpd-table-configurations ((record-accessor <record-type> fieldname) value)))
+                                   list-of-record-fieldnames)))
+                           ((and (list? value) (not (null? list)))
+                            (map (lambda (element-in-list)
+                                   (if (record? element-in-list)
+                                       (get-opensmtpd-table-configurations element-in-list)
+                                       #f))
+                                 value))))])
+     (if (null? list)
+         '()
+         (if (opensmtpd-table-configuration? (car list))
+             (cons (car list) (loop (cdr list)))
+             (loop (cdr list)))))))
+
+(define (get-opensmtpd-table-configurations value)
+   (let loop ([list (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+                     (cond ((opensmtpd-table-configuration? value)
+                            value)
+                           ((record? value)
+                            (let* ([<record-type> (record-type-descriptor value)]
+                                   [list-of-record-fieldnames (record-type-fields <record-type>)])
+                              (map (lambda (fieldname)
+                                     (get-opensmtpd-table-configurations ((record-accessor <record-type> fieldname) value)))
+                                   list-of-record-fieldnames)))
+                           ((and (list? value) (not (null? list)))
+                            (map (lambda (element-in-list)
+                                   (if (record? element-in-list)
+                                       (get-opensmtpd-table-configurations element-in-list)
+                                       #f))
+                                 value))))])
+     (delete-duplicates (partition opensmtpd-table-configuration? list))))
+
+#+END_SRC
+**** TODO  using map, apply, and fold is certainly awesome, but is it less efficient?
+
+For example, list-of-type? using a named let is pretty efficient.  It loops
+through the list once.
+
+#+BEGIN_SRC scheme
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ([list list])
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+#+END_SRC
+
+BUT when I using map on this, it is slightly less efficient.  It has to apply a
+simple procedure to each element in the list.  Then it has to return the list of
+booleans.  Then it has to build the primitive eval list, then it has to eval it.
+#+BEGIN_SRC scheme
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (primitive-eval (cons 'and
+                            (map (lambda (var)
+                                   (if (proc? var)
+                                       #t
+                                       #f))
+                                 list)))
+      #f))
+#+END_SRC
+
+*** PROJ improve <opensmtpd-table-configuration> [0/2]
+**** TODO it would be nice if ~<opensmtpd-table-configuration>~ supported aliasing tables, as described in man 5 table
+
+#+BEGIN_EXAMPLE
+   Aliasing tables
+     Aliasing tables are mappings that associate a recipient to one or many destinations.  They can be
+     used in two contexts: primary domain aliases and virtual domain mapping.
+
+           action name method alias <table>
+           action name method virtual <table>
+
+     In a primary domain context, the key is the user part of the recipient address, whilst the value
+     is one or many recipients as described in aliases(5):
+
+           user1   otheruser
+           user2   otheruser1,otheruser2
+           user3   otheruser@example.com
+
+     In a virtual domain context, the key is either a user part, a full email address or a catch all,
+     following selection rules described in smtpd.conf(5), and the value is one or many recipients as
+     described in aliases(5):
+
+           user1                   otheruser
+           user2@example.org       otheruser1,otheruser2
+           @example.org            otheruser@example.com
+           @                       catchall@example.com
+
+#+END_EXAMPLE
+
+Currently opensmtpd-table-configuration, does not support mapping a user to 5 email addresses.
+For example, if user 'dave' can email as 'postmaster@gnu.org', and
+'other@gnu.org', and 5 other email addresses...<opensmtpd-table-configuration> does not
+support this kind of mapping.  To support it, I may be able to just embed a
+table in smtpd.conf, or I may need to create an /etc/aliases table as man 5
+aliases describes.
+**** TODO make an <opensmtpd-table-configuration> with file-db #t, auto convert the table into a berkley database via makemap
+
+See man 5 table
+and man smtpd.conf
+*** TODO writing out the pkis when there are no pkis gives the string "\n"...it might be better to give "" instead
+
+=(opensmtpd-configuration-fieldname->string example-opensmtpd-with-0-pkis opensmtpd-configuration-pkis opensmtpd-pki-configuration->string)=
+*** PROJ Can I make some improvements to my/sanitize procedure? [0/5]
+**** how does my/sanitize procedure work?
+
+~(my/sanitize var "record-name" "fieldname" '(string? boolean? number?)')~
+
+It is essentially asking? are you any of the following: string?, boolean?,
+number?  If not, then error out with a helpful error message.
+
+**** How does my hard-coded sanitized procedure work? eg [[file:opensmtpd-records.scm::(filters opensmtpd-listen-on-configuration-filters][opensmtpd-listen-on-configuration-filters]]
+
+This hard coded sanitize is a little different than the my/sanitize procedure. I
+designed the thunk ~my/sanitize~, such that each thunk (string?, false?,
+boolean?) has a corresponding entry in the procedure [[file:opensmtpd-records.scm::define (list-of-procedures->string
+ procedures][~(list-of-procedures->string procedures)~]].
+
+However, it would be nice to have the sanitize invocation in
+opensmtpd-listen-on-configuration-filters use a my/sanitize invocation like so.
+
+#+BEGIN_SRC scheme
+(my/sanitize var "opensmtpd-listen-on-configuration" "filters"
+             (list false?
+                   '(list-has-duplicates-or-non-filters
+                     "is a list in which each unique element is of type <opensmtpd-filter-configuration>\n"
+                     "or <opensmtpd-filter-phase-configuration>.")
+                   '(some-filters-in-list-need-message?
+                     "<opensmtpd-filter-phase-configuration> fieldname: 'decision' options "
+                     "\"disconnect\" and \"reject\" require fieldname 'message'\n"
+                     "to have a string.\n")
+                   '(some-filters-in-list-need-value?
+                     "<opensmtpd-filter-phase-configuration> fieldname: 'decision' option "
+                     "\"rewrite\" requires fieldname 'value'\n"
+                     "to have a string.\n")))
+#+END_SRC
+
+**** PROJ better error messages for my/sanitize calls that use a lambda instead of a defined function [0/4]
+
+THIS IS HARD TO DO... NOT DOING IT! I just chose to use a hard-coded error
+message baked into the lambda. I tried making my/sanitize better...but I could
+not get it to work.  The hard-coded method just works:
+
+#+BEGIN_SRC scheme
+(phase-name opensmtpd-filter-phase-configuration-phase-name ;; string
+              (default #f)
+              (sanitize (lambda (var)
+                          (if (and (string? var)
+                                   (or (string=? "connect" var)
+                                       (string=? "helo" var)
+                                       (string=? "mail-from" var)
+                                       (string=? "rcpt-to" var)
+                                       (string=? "data" var)
+                                       (string=? "commit" var)))
+                              var
+                              (begin
+                                (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'phase-name' is of type "
+                                                        "string.  The string can be either 'connect',"
+                                                        " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n "))
+                                (throw 'bad! var))))))
+#+END_SRC
+
+Why? ~<opensmtpd-filter-phase-configuration>~ fieldnames only accept certain strings. I want to
+sanitize each fieldname to make sure that it's strings is one of those strings.
+How would I do this?
+
+For example, ~<opensmtpd-filter-phase-configuration>~ fieldname 'decision' uses
+a lambda to sanitize itself. This will result in an error message that is
+descriptive enough to solve the problem. If I decide to do this, then I probably
+should create a non-exported record.
+
+#+BEGIN_SRC scheme
+(opensmtpd-filter-phase-configuration (name "cat") (phase-name "connect") (options "fcrdns") (decision "bypasse"))
+#+END_SRC
+
+#+RESULTS:
+: (opensmtpd-filter-phase-configuration (name "cat") (phase-name "connect") (options "fcrdns") (decision "bypasse"))
+: <opensmtpd-filter-phase> fieldname 'bypasse' is of type.
+: #<procedure 3ec75a8 at <unknown port>:972:0 (var)>
+: ice-9/boot-9.scm:1685:16: In procedure raise-exception:
+: Throw to key `bad!' with args `(#<procedure 3ec75a8 at <unknown port>:972:0 (var)>)'.
+
+A solution may be to modify the my/sanitize procedure to accept something like
+
+#+BEGIN_SRC scheme
+(my/sanitize var "<record>" "'fieldname'" (list ((lambda (var) ...) . "list of unique numbers or strings")))
+#+END_SRC
+
+I have some example code [[file:opensmtpd-records.scm::;; TODO add in some code that accepts a (cons . cell) that of (proc . "error message") here.][here.]]  It probably won't work, but it is a rough sketch
+of what could work.
+#+BEGIN_SRC scheme
+[(eq? (cons? (car procedures)))
+(cdr (car procedures))]
+#+END_SRC
+
+Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
+
+***** TODO Now make all the other sanitize sections that use a lambda use this new functionality:
+
+eg:
+
+#+BEGIN_SRC scheme
+(family opensmtpd-listen-on-configuration-family
+          (default #f)
+          (sanitize (lambda (var)
+                      (cond
+                       [(eq? #f var) ;; var == #f
+                        var]
+                       [(and (string? var)
+                             (or (string=? "inet4" var)
+                                 (string=? "inet6" var)))
+                        var]
+                       [else
+                        (begin
+                          (display "<opensmtpd-listen-on-configuration> fieldname 'family' must be string \"inet4\" or \"inet6\".\n")
+                          (throw 'bad! var))]))))
+#+END_SRC
+
+***** TODO perhaps I can create an unexported record <sanitize-proc-configuration> [0/2]
+
+fieldnames: 'procedure', 'error message'.
+***** TODO Perhaps I could try to make my/sanitize work more like the opensmtpd-listen-on-configuration-filters does.
+
+It looks like tiny errors first.  And shows you those relevent errors.  When you
+fix those tiny errors it starts looking for harder errors.
+
+This is nice because when you get something wrong in the config, you get the
+specific error message.
+
+The way my/sanitize currently works, if you get one thing wrong, then you get 4
+reasons for what you might have done wrong.
+***** TODO the <opensmtpd-match-configuration> has lost of hard coded error checking.
+It would be nice to hook this up to my/sanitize.  Along with other bits of the code.
+**** TODO rework my/sanitize to be like opensmtpd-listen-on-configuration-filters
+
+opensmtpd-listen-on-configuration-filters works like so:
+
+Is the variable (not (false? var))
+
+Is the variable (need-some-messages?)
+
+Does the variable (need-some-value) ?
+
+else var.
+
+For example, this
+#+BEGIN_SRC scheme
+(define-record-type* <opensmtpd-table-configuration>
+  opensmtpd-table-configuration make-opensmtpd-table-configuration
+  opensmtpd-table-configuration?
+  this-record
+  (name opensmtpd-table-configuration-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table-configuration" "name" (list string?)))))
+  (file-db opensmtpd-table-configuration-file-db
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-table-configuration" "file-db"
+                                    (list boolean?)))))
+#+END_SRC
+
+would become:
+#+BEGIN_SRC scheme
+(define-record-type* <opensmtpd-table-configuration>
+  opensmtpd-table-configuration make-opensmtpd-table-configuration
+  opensmtpd-table-configuration?
+  this-record
+  (name opensmtpd-table-configuration-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table-configuration" "name" (list not-string?)))))
+  (file-db opensmtpd-table-configuration-file-db
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-table-configuration" "file-db"
+                                    (list not-boolean?)))))
+#+END_SRC
+
+This
+#+BEGIN_SRC scheme
+(secure-connection opensmtpd-listen-on-configuration-secure-connection
+                     (default #f)
+                     (sanitize (lambda (var)
+                                 (cond [(boolean? var)
+                                        var]
+                                       [(and (string? var)
+                                             (string-in-list? var
+                                                              (list "smtps" "tls"
+                                                                    "tls-require"
+                                                                    "tls-require-verify")))
+                                        var]
+                                       [else
+                                        (begin
+                                          (display (string-append "<opensmtd-listen-on> fieldname 'secure-connection' can be "
+                                                                  "one of the following strings: \n'smtps', 'tls', 'tls-require', "
+                                                                  "or 'tls-require-verify'.\n"))
+                                          (throw 'bad! var))]))))
+#+END_SRC
+
+would become  (finish this thought exercise.)
+#+BEGIN_SRC scheme
+(secure-connection opensmtpd-listen-on-configuration-secure-connection
+                     (default #f)
+                     (sanitize (lambda (var)
+                                 (list not-boolean
+                                       (sanitize-proc-configuration
+                                        string-in-list?
+                                                        (list "smtps" "tls"
+                                                              "tls-require"
+                                                              "tls-require-verify"))
+                                       [else
+                                        (begin
+                                          (display (string-append "<opensmtd-listen-on> fieldname 'secure-connection' can be "
+                                                                  "one of the following strings: \n'smtps', 'tls', 'tls-require', "
+                                                                  "or 'tls-require-verify'.\n"))
+                                          (throw 'bad! var))]))))
+#+END_SRC
+
+**** PROJ can we merge my/sanitize syntax into (guix records)?
+
+#+BEGIN_SRC scheme
+(define-record-type* <opensmtpd-option-configuration>
+  opensmtpd-option-configuration make-opensmtpd-option-configuration
+  opensmtpd-option-configuration?
+  (documentation (list "<opensmtpd-match-configuration> uses <opensmtpd-option-configuration> to\n"
+                       "tweak various options."))
+  (sanitize (sanitize-configuration ; this sanitizes the whole <opensmtpd-option-configuration> record.
+             (list (lambda (value)
+                     ...
+                     ))))
+  (option opensmtpd-option-configuration-option
+          (default #f)
+          (sanitize (sanitize-configuration
+                     (list string?))))
+  (not opensmtpd-option-configuration-not
+       (default #f)
+       (sanitize (sanitize-configuration
+                  (list boolean?)) ))
+  (regex opensmtpd-option-configuration-regex
+         (default #f)
+         (sanitize (sanitize-configuration '(boolean?))))
+  (value opensmtpd-option-configuration-value
+         (default #f)
+         (sanitize (sanitize-configuration
+                    ;; note that it is smart enough to realize that opensmtpd-table-configuration? is a record,
+                    ;; so the error message it returns is something like "<opensmtpd-match-configuration> fieldname is of
+                    ;; type <opensmtpd-table-configuration>."
+                    (list false? string? opensmtpd-table-configuration?)))))
+#+END_SRC
+**** TODO maybe sanitize the ~<opensmtpd-configuration>~ fieldname 'matches' better
+
+#+BEGIN_SRC scheme
+(opensmtpd-configuration (matches (list
+                                   (opensmtpd-match-configuration
+                                    (action
+                                     (opensmtpd-action-relay-configuration
+                                      (name "relay"))))
+                                   345
+                                   (opensmtpd-match-configuration
+                                    (for (opensmtpd-option-configuration
+                                          (option "for local")))
+                                    (action
+                                     (opensmtpd-action-relay-configuration
+                                      (name "relay")))))))
+#+END_SRC
+
+#+BEGIN_EXAMPLE
+<opensmtpd-configuration> fieldname: 'matches' is of type a list of unique <opensmtpd-match-configuration> records.
+
+ice-9/boot-9.scm:1685:16: In procedure raise-exception:
+Throw to key `bad!' with args `((#<<opensmtpd-match-configuration> action: #<<opensmtpd-action-relay-configuration> name: "relay" backup: #f backup-mx: #f helo: #f domain: #f host: #f pki: #f srs: #f tls: #f protocols: #f ciphers: #f auth: #f mail-from: #f src: #f> for: #f from: #f auth: #f helo: #f mail-from: #f rcpt-to: #f tag: #f tls: #f> 345 #<<opensmtpd-match-configuration> action: #<<opensmtpd-action-relay-configuration> name: "relay" backup: #f backup-mx: #f helo: #f domain: #f host: #f pki: #f srs: #f tls: #f protocols: #f ciphers: #f auth: #f mail-from: #f src: #f> for: #<<opensmtpd-option-configuration> option: "for local" not: #f regex: #f value: #f> from: #f auth: #f helo: #f mail-from: #f rcpt-to: #f tag: #f tls: #f>))'.
+
+Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
+scheme@(opensmtpd-records) [24]> ,bt
+In current input:
+   2358:0  2 (_)
+In /home/joshua/prog/gnu/guix/guix-config/linode-guix-system-configuration/opensmtpd-records.scm:
+    278:8  1 (my/sanitize (#<<opensmtpd-match-configuration> action: #<<opensmtpd-action-relay-configuration> name: "relay" backup: #f backup-mx: #f helo: #f domain…> …) …)
+In ice-9/boot-9.scm:
+  1685:16  0 (raise-exception _ #:continuable? _)
+#+END_EXAMPLE
+
+It is not obvious from the error message what is wrong.  The error message
+should say
+
+#+BEGIN_SRC org
+~<opensmtpd-configuration>= fieldname 'matches' is a list of unique =<opensmtpd-match-configuration>~.  One of the items in the list
+is '345'.
+Throw to key `bad! with args 345
+#+END_SRC
+
+Alternatively, we could define a guix specific record printer to make it easier
+to see the problem.
+
+#+BEGIN_SRC scheme
+<opensmtpd-configuration> fieldname: 'matches' is of type a list of unique <opensmtpd-match-configuration> records.
+
+ice-9/boot-9.scm:1685:16: In procedure raise-exception:
+Throw to key `bad!' with args:
+`(list
+  (opensmtpd-match-configuration
+   (action
+    (opensmtpd-action-relay-configuration
+     (name "relay"))))
+  345
+  (opensmtpd-match-configuration
+   (for (opensmtpd-option-configuration
+         (option "for local")))
+   (action
+    (opensmtpd-action-relay-configuration
+     (name "relay")))))'.
+
+Entering a new prompt.  Type `,bt' for a backtrace or `,q' to continue.
+scheme@(opensmtpd-records) [24]> ,bt
+In current input:
+   2358:0  2 (_)
+In /home/joshua/prog/gnu/guix/guix-config/linode-guix-system-configuration/opensmtpd-records.scm:
+    278:8  1 (my/sanitize (#<<opensmtpd-match-configuration> action: #<<opensmtpd-action-relay-configuration> name: "relay" backup: #f backup-mx: #f helo: #f domain…> …) …)
+In ice-9/boot-9.scm:
+  1685:16  0 (raise-exception _ #:continuable? _)
+
+#+END_SRC
+**** TODO some of the error messages say "bad var #f".  This is not very helpful.
+
+Where it is useful I should do a ~(throw 'bad! record)~ instead of
+~(throw `bad! #f)~
+*** PROJ add support for ~<listen-on>= fieldname 'senders': syntax "senders =<users>~ [masquerade]" [0/4]
+:LOGBOOK:
+- State "TODO"       from              [2021-11-02 Tue 04:08]
+:END:
+**** TODO add a record type <opensmtpd-senders-configuration>
+
+fieldnames: 'table (accepts <opensmtpd-table-configuration>'), and 'masquerade' (accepts boolean).
+**** TODO change the sanitize portion of the fieldname 'senders' in the <opensmtpd-listen-on-configuration>
+
+The below code does work in a REPL.
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (auth
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '(("joshua" . "$some$Long$EncrytpedPassword"))))))
+#+END_SRC
+
+#+RESULTS:
+
+AND the below code will correctly result in an error!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+(opensmtpd-listen-on-configuration
+ (auth
+  (opensmtpd-table-configuration
+   (name "My-table")
+   (data '("joshua" "$some$Long$EncrytpedPassword")))))
+#+END_SRC
+
+#+RESULTS:
+: ~<opensmtpd-listen-on-configuration>= fieldname: 'auth' is of type boolean, or an =<opensmtpd-table-configuration>~ record whose fieldname 'values' are an assoc-list
+: (eg: (opensmtpd-table-configuration (name "table") (data '("joshua" . "$encrypted$password")))).
+
+**** TODO change relevant portions in opensmtpd-listen-on-configuration->string
+This bit of code works in the repl too!
+#+BEGIN_SRC scheme :dir ~/prog/gnu/guix-config/linode-guix-system-configuration/
+(add-to-load-path (dirname (current-filename)))
+(use-modules (opensmtpd-records))
+
+((@@ (opensmtpd-records) opensmtpd-listen-on-configuration->string)
+ (opensmtpd-listen-on-configuration
+  (auth
+   (opensmtpd-table-configuration
+    (name "credentials")
+    (data '(("joshua" . "$someLongEncrytpedPassword")))))))
+#+END_SRC
+
+**** TODO support the masquerade option
+
+Right now, senders just accepts an <opensmtpd-table-configuration>, but I am not allowing the
+user to turn on or off the masquerade option.
+*** TODO write out of examples of ~<opensmtpd-configuration>~ records that will fail to start or do not make sense.
+Provide appropriate error messages.
+
+There is a trend of guix services that "work" but are not dummy proof. For
+example, the XMPP service wants a cert in the format of "</path/to/cert.key". If
+you omit that leading "<", then the service will not start, and you will NOT
+have any error messages telling you why. It's not easy to figure out what went
+wrong with the service.
+
+Shepherd will not tell where the XMPP configuration file can be found. You have
+to manually go searching for the config file. Then you have to manually check
+the configuration syntax of the file, though the command to start the service
+may have a flag to check the syntax. Anyway it's annoying. Guix services should
+be able to get a ~<service-configuration>~ record and just by looking at the
+record tell, if you have done something silly that will make the service refuse
+to start or behave in a weird way, and provide you appropriate error messages so
+you don't have to go syntax hunting.
+
+Examples:
+
+- could be a filter that is defined but never used, which won't
+be possible once [[id:89603b3f-7580-4531-8aee-2c115c97adfe][remove opensmtpd-configuration-filters]] is done.
+
+- (listen-on (interface "doesNotExist"))
+
+- (smtp-configuration (smtp-max-message-size "10G"))  Are you sure you
+  want emails that large?
+
+- (pki (domain "name") (key "notAKeyfile.txt") (cert
+  "notACertFile.txt")
+
+- (ca (file "NotACaFile.txt"))
+
+- (opensmtpd-filter-phase-configuration (name "filter") (phase "helo") (decision "bypass"))
+  There is no fieldname =options= here.  This has to be sanitized by
+  ~<opensmtpd-filter-phase-configuration>~'s fieldname 'filters'.
+
+
+#+BEGIN_SRC scheme
+(opensmtpd-listen-on-configuration
+ (filters
+  (list
+   (opensmtpd-filter-phase-configuration
+    (name "noFRDNS")
+    (phase "commit")
+    (options (list (opensmtpd-option-configuration
+                    (option "fcrdns")
+                    )))
+    (decision "junk")))))
+#+END_SRC
+* Some notes on working on the service workflows and such
+
+disabling centaur-tabs-mode seems to help.  and NOT working in the console helps too.
+
+I think that having the geiser repl running via
+
+M-x geiser
+M-x geiser-load-file RET opensmtpd-records.scm
+,m (opensmtpd-records)
+
+May be causing Emacs to move slowly after a while.
+
+
+It may be better to instead do:
+
+cd prog/gnu/guix-config/linode-system-configuration;
+guile -L . --listen=9999
+
+And then in Emacs (as described here: https://www.nongnu.org/geiser/geiser_3.html)
+connect to the external repl via
+M-x geiser-connect
-- 
2.36.1





^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2
  2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
  2022-06-17 21:54 ` [bug#56046] [PATCH] gnu: services: opensmtpd-records-task-list.org: Some notes about how I thought about building this service. And some additional task lists, as well as the WIP documentation Joshua Branson via Guix-patches via
@ 2022-07-04 21:17 ` Joshua Branson via Guix-patches via
  2022-07-06  4:27   ` Liliana Marie Prikler
  2022-07-06 21:51   ` jbranso--- via Guix-patches via
  2022-07-05 21:36 ` jbranso--- via Guix-patches via
                   ` (3 subsequent siblings)
  5 siblings, 2 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-07-04 21:17 UTC (permalink / raw)
  To: 56046; +Cc: Joshua Branson

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 155460 bytes --]

Openmstpd-configuration may only be configured by a config-file.  This
patch, enables one to configure opensmtpd by using some guile record
types (defined via define-record-type*).

* gnu/services/mail.scm:  New records (opensmtpd-table-configuration),
(opensmtpd-ca-configuration),
(opensmtpd-pki-configuration),
(opensmtpd-action-local-delivery-configuration),
(opensmtpd-maildir-configuration),
(opensmtpd-mda-configuration),
(opensmtpd-action-relay-configuration),
(opensmtpd-option-configuration),
(opensmtpd-filter-phase-configuration),
(opensmtpd-filter-configuration),
(opensmtpd-listen-on-configuration),
(opensmtpd-listen-on-socket-configuration),
(opensmtpd-match-configuration),
(opensmtpd-smtp-configuration),
(opensmtpd-srs-configuration),
(opensmtpd-queue-configuration), and
(opensmtpd-configuration).

New procedures: false?, is-value-right-type, add-comma-or-string,
file-exists?, list-of-procedures->string, string-in-list?, my-sanitize,
opensmtpd-filter-chain?, throw-error-duplicate-option,
sanitize-list-of-options-for-match-configuration, sanitize-filters,
list-has-duplicates-or-non-filters?,
filter-phase-has-message-and-value?,
filter-phase-decision-lacks-proper-message?,
filter-phase-lacks-proper-value?,
filter-phase-has-incorrect-junk-or-bypass?,
filter-phase-junks-after-commit?,
list-of-unique-filter-or-filter-phase?, throw-error,
contains-duplicate?, list-of-type?, list-of-strings?,
list-of-unique-opensmtpd-option-configuration?,
list-of-opensmtpd-ca-configuration?,
list-of-opensmtpd-pki-configuration?,
list-of-opensmtpd-listen-on-configuration?,
list-of-unique-opensmtpd-match-configuration?, list-of-strings->string,
assoc-list? assoc-list, variable->string,
table-whose-data-are-assoc-list?,
table-whose-data-are-a-list-of-strings?, assoc-list->string,
opensmtpd-table-configuration->string,
opensmtpd-listen-on-configuration->string,
opensmtpd-listen-on-socket-configuration->string,
opensmtpd-action-relay-configuration->string,
opensmtpd-lmtp-configuration->string,
opensmtpd-mda-configuration->string,
opensmtpd-maildir-configuration->string,
opensmtpd-action-local-delivery-configuration->string,
opensmtpd-action->string, opensmtpd-option-configuration->string,
opensmtpd-match-configuration->string,
opensmtpd-ca-configuration->string, opensmtpd-pki-configuration->string,
generate-filter-chain-name, opensmtpd-filter-chain->string,
opensmtpd-filter-phase-configuration->string, opensmtpd-filters->string,
opensmtpd-configuration-listen->string,
opensmtpd-configuration-srs->string,
opensmtpd-smtp-configuration->string,
opensmtpd-configuration-queue->string, get-opensmtpd-actions,
get-opensmtpd-pki-configurations, get-opensmtpd-filters, flatten,
get-opensmtpd-tables, opensmtpd-configuration-fieldname->string,
list-of-records->string, opensmtpd-configuration->mixed-text-file.

* doc/guix.texi added documentation for the new records for opensmtpd.
---
 doc/guix.texi         | 1051 ++++++++++++++++++++-
 gnu/services/mail.scm | 2016 ++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 3056 insertions(+), 11 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index eda0956260..e8564240d1 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -24849,14 +24849,59 @@ could instantiate a dovecot service like this:
 @subsubheading OpenSMTPD Service
 
 @deffn {Scheme Variable} opensmtpd-service-type
-This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
-service, whose value should be an @code{opensmtpd-configuration} object
-as in this example:
-
-@lisp
-(service opensmtpd-service-type
-         (opensmtpd-configuration
-           (config-file (local-file "./my-smtpd.conf"))))
+OpenSMTPD is an easy-to-use mail transfer agent (MTA). Its configuration file is
+throughly documented in @code{man 5 smtpd.conf}. OpenSMTPD @strong{listens} for incoming
+mail and @strong{matches} the mail to @strong{actions}. The following records represent those
+stages:
+
+@multitable {aaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @strong{listens}
+@tab @code{<opensmtpd-listen-on-configuration}
+@item
+@tab @code{<opensmtpd-listen-on-socket-configuration>}
+@item
+@tab
+@item @strong{matches}
+@tab @code{<opensmtpd-match-configuration>}
+@item
+@tab
+@item @strong{actions}
+@tab @code{<opensmtpd-action-local-delivery-configuration>}
+@item
+@tab @code{<opensmtpd-action-relay-configuration>}
+@end multitable
+
+Additionally, each @code{<opensmtpd-listen-on-configuration>} and
+@code{<opensmtpd-listen-on-socket-configuration>} may use a list of
+@code{<opensmtpd-filter-configuration>}, and/or
+@code{<opensmtpd-filter-phase-configuration>} records to filter email/spam. Also
+numerous records' fieldnames use @code{<opensmtpd-table-configuration>} to hold lists
+or key value pairs of data.
+
+A simple example configuration is below:
+
+@lisp
+(let ((smtp.gnu.org (opensmtpd-pki-configuration
+                        (domain "smtp.gnu.org")
+                        (cert "file.cert")
+                        (key "file.key"))))
+  (service opensmtpd-service-type
+           (opensmtpd-configuration
+            (listen-ons (list
+                         (opensmtpd-listen-on-configuration
+                          (pki smtp.gnu.org))
+                         (opensmtpd-listen-on-configuration
+                          (pki smtp.gnu.org)
+                          (secure-connection "smtps"))))
+            (matches (list
+                      (opensmtpd-match-configuration
+                       (action
+                        (opensmtpd-action-local-delivery-configuration
+                         (name "local-delivery"))))
+                      (opensmtpd-match-configuration
+                       (action
+                        (opensmtpd-action-relay-configuration
+                         (name "relay")))))))))
 @end lisp
 @end deffn
 
@@ -24873,9 +24918,999 @@ it listens on the loopback network interface, and allows for mail from
 users and daemons on the local machine, as well as permitting email to
 remote servers.  Run @command{man smtpd.conf} for more information.
 
+@item @code{bounce} (default: @code{(list "4h")})
+
+@code{bounce} is a list of strings, which send warning messages to the envelope
+sender when temporary delivery failures cause a message to remain in the
+queue for longer than string delay. Each string delay parameter consists
+of a string beginning with a positive decimal integer and a unit 's', 'm', 'h',
+or 'd'. At most four delay parameters can be specified.
+
+@item @code{listen-ons} (default: @code{(list (opensmtpd-listen-on-configuration))})
+
+@code{listen-ons} is a list of @code{<opensmtpd-listen-on-configuration>} records.
+This list details what interfaces and ports OpenSMTPD listens on as well as
+other information.
+
+@item @code{listen-on-socket} (default: @code{(opensmtpd-listen-on-socket-configuration-configuration)})
+
+Listens for incoming connections on the Unix domain socket.
+
+@item @code{includes} (default: @code{#f})
+
+@code{includes} is a list of string filenames. Each filename's contents is
+additional configuration that is inserted into the top of the configuration
+file.
+
+@item @code{matches} default:
+
+@lisp
+    (list (opensmtpd-match-configuration
+           (action (opensmtpd-action-local-delivery-configuration
+                    (name "local")
+                    (method "mbox")))
+           (for (opensmtpd-option-configuration
+                 (option "for local"))))
+          (opensmtpd-match-configuration
+           (action (opensmtpd-action-relay-configuration
+                    (name "outbound")))
+           (from (opensmtpd-option-configuration
+                  (option "from local")))
+           (for (opensmtpd-option-configuration
+                 (option "for any")))))
+@end lisp
+
+@code{matches} is a list of @code{<opensmtpd-match-configuration>} records, which
+matches incoming mail and sends it to a correspending action. The match
+records are evaluated sequentially, with the first match winning. If an
+incoming mail does not match any match records, then it is rejected.
+@c put this backin? @end itemize
+
+@c put this back in? @itemize
+@item @code{mta-max-deferred} (default: @code{100})
+
+When delivery to a given host is suspended due to temporary failures, cache
+at most number envelopes for that host such that they can be delivered as
+soon as another delivery succeeds to that host. The default is 100.
+
+@item @code{queue} (default: @code{#f})
+
+@code{queue} expects an @code{<opensmtpd-queue-configuration>} record. With it, one may
+compress and encrypt queue-ed emails as well as set the default expiration
+time for temporarily undeliverable messages.
+
+@item @code{smtp} (default: @code{#f})
+
+@code{smtp} expects an @code{<opensmtpd-smtp-configuration>} record, which lets one
+specifiy how large email may be along with other settings.
+
+@item @code{srs} (default: @code{#f})
+
+@code{srs} expects an @code{<opensmtpd-srs-configuration>} record, which lets one set
+up SRS, the Sender Rewritting Scheme.
 @end table
 @end deftp
 
+@itemize
+@item
+Data Type: opensmtpd-listen-on-configuration
+
+Data type representing the configuration of an
+@code{<opensmtpd-listen-on-configuration>}. Listen on the fieldname @code{interface} for
+incoming connections, using the same syntax as for ifconfig(8). The interface
+parameter may also be an string interface group, an string IP address, or a
+string domain name. Listening can optionally be restricted to a specific
+address fieldname @code{family}, which can be either ``inet4'' or ``inet6''.
+
+@itemize
+@item @code{interface} (default: ``lo'')
+
+The string interface to listen for incoming connections. These interface can
+usually be found by the command @code{ip link}.
+
+@item @code{family} (default: @code{#f})
+
+The string IP family to use.  Valid strings are ``inet4'' or ``inet6''.
+
+@item @code{auth} (default: @code{#f})
+
+Support SMTPAUTH: clients may only start SMTP transactions after successful
+authentication. If @code{auth} is @code{#t}, then users are authenticated against
+their own normal login credentials. Alternatively @code{auth} may be an
+@code{<opensmtpd-table-configuration>} whose users are authenticated against
+their passwords.
+
+@item @code{auth-optional} (default: @code{#f})
+
+Support SMTPAUTH optionally: clients need not authenticate, but may do so.
+This allows the @code{<opensmtpd-listen-on-configuration>} to both accept
+incoming mail from untrusted senders and permit outgoing mail from
+authenticated users (using @code{<opensmtpd-match-configuration>} fieldname
+@code{auth}). It can be used in situations where it is not possible to listen on
+a separate port (usually the submission port, 587) for users to
+authenticate.
+
+@item @code{filters} (default: @code{#f})
+
+A list of one or many @code{<opensmtpd-filter-configuration>} or
+@code{<opensmtpd-filter-phase-configuration>} records. The filters are applied
+sequentially. These records listen and filter on connections handled by this
+listener.
+
+@item @code{hostname} (default: @code{#f})
+
+Use string ``hostname'' in the greeting banner instead of the default server
+name.
+
+@item @code{hostnames} (default: @code{#f})
+
+Override the server name for specific addresses. Use a
+@code{<opensmtpd-table-configuration>} containing a mapping of string IP
+addresses to hostnames. If the address on which the connection arrives
+appears in the mapping, the associated hostname is used.
+
+@item @code{mask-src} (default: @code{#f})
+
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{disable-dsn} (default: @code{#f})
+
+When @code{#t}, then disable the DSN (Delivery Status Notification) extension.
+
+@item @code{pki} (default: @code{#f})
+
+For secure connections, use an @code{<opensmtpd-pki-configuration>}
+to prove a mail server's identity.
+
+@item @code{port} (default: @code{#f})
+
+Listen on the integer port instead of the default port of 25.
+
+@item @code{proxy-v2} (default: @code{#f})
+
+If @code{#t}, then support the PROXYv2 protocol, rewriting appropriately source
+address received from proxy.
+
+@item @code{received-auth} (default: @code{#f})
+
+If @code{#t}, then in “Received” headers, report whether the session was
+authenticated and by which local user.
+
+@item @code{senders} (default: @code{#f})
+
+Look up the authenticated user in the supplied
+@code{<opensmtpd-table-configuration>} to find the email addresses that user is
+allowed to submit mail as.
+
+@item @code{secure-connection} (default: @code{#f})
+
+This is a string of one of these options:
+
+@multitable {aaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``smtps''
+@tab Support SMTPS, by default on port 465.
+@item ``tls''
+@tab Support STARTTLS, by default on port 25.
+@item ``tls-require-verify''
+@tab Like tls, but force clients to establish
+@item
+@tab a secure connection before being allowed to
+@item
+@tab start an SMTP transaction.  With the verify
+@item
+@tab option, clients must also provide a valid
+@item
+@tab certificate to establish an SMTP session.
+@end multitable
+
+@item @code{tag} (default: @code{#f})
+
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-listen-on-socket-configuration
+
+Data type representing the configuration of an
+@code{<opensmtpd-listen-on-socket-configuration>}. Listen for incoming SMTP
+connections on the Unix domain socket @samp{/var/run/smtpd.sock}. This is done by
+default, even if the directive is absent.
+
+@itemize
+@item @code{filters} (default: @code{#f})
+
+A list of one or many @code{<opensmtpd-filter-configuration>} or
+@code{<opensmtpd-filter-phase-configuration>} records. These filter incoming
+connections handled by this listener.
+
+@item @code{mask-src} (default: @code{#f})
+
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{tag} (default: @code{#f})
+
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-match-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-match-configuration>} record.
+
+If at least one mail envelope matches the options of one match record, receive
+the incoming message, put a copy into each matching envelope, and atomically
+save the envelopes to the mail spool for later processing by the respective
+@code{<opensmtpd-action-configuration>} found in fieldname @code{action}.
+
+@itemize
+@item @code{action} (default: @code{#f})
+
+If mail matches this match configuration, then do this action. Valid values
+include @code{<opensmtpd-action-local-delivery-configuration>} or
+@code{<opensmtpd-action-relay-configuration>}.
+
+@item @code{options} (default: @code{#f}) @code{<opensmtpd-option-configuration>}
+The fieldname 'option' is a list of unique
+@code{<opensmtpd-option-configuration>} records.
+
+Each @code{<opensmtpd-option-configuration>} record's fieldname 'option' has some
+mutually exclusive options: there can be only one ``for'' and only one ``from'' option.
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@headitem for
+@tab from
+@item only use one of the following:
+@tab only use one of the following:
+@item ``for any''
+@tab ``from any''
+@item ``for local''
+@tab ``from auth''
+@item ``for domain''
+@tab ``from local''
+@item ``for rcpt-to''
+@tab ``from mail-from''
+@item
+@tab ``from socket''
+@item
+@tab ``from src''
+@end multitable
+
+The following matching options are supported and can all be negated (via not
+#t). The options that support a table (anything surrounded with '<' and '>'
+eg: <table>), also support specifying regex via (regex #t).
+
+@itemize
+@item @samp{for any}
+
+Specify that session may address any destination.
+
+@item @samp{for local}
+
+Specify that session may address any local domain.  This is the default,
+and may be omitted.
+
+@item @samp{for domain _domain_ | <domain>}
+
+Specify that session may address the string or list table domain.
+
+@item @samp{for rcpt-to _recipient_ | <recipient>}
+
+Specify that session may address the string or list table recipient.
+
+@item @samp{from any}
+
+Specify that session may originate from any source.
+
+@item @samp{from auth}
+
+Specify that session may originate from any authenticated user, no matter
+the source IP address.
+
+@item @samp{from auth _user_ | <user>}
+
+Specify that session may originate from authenticated user or user list
+user, no matter the source IP address.
+
+@item @samp{from local}
+
+Specify that session may only originate from a local IP address, or from
+the local enqueuer.  This is the default, and may be omitted.
+
+@item @samp{from mail-from _sender_ | <sender>}
+
+Specify that session may originate from sender or table sender, no
+matter the source IP address.
+
+@item @samp{from rdns}
+
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS@.
+
+@item @samp{from rdns _hostname_ | <hostname>}
+
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS matching string or list string hostname.
+
+@item @samp{from socket}
+
+Specify that session may only originate from the local enqueuer.
+
+@item @samp{from src _address_ | <address>}
+
+Specify that session may only originate from string or list table address
+which can be a specific address or a subnet expressed in CIDR-notation.
+
+@item @samp{auth}
+
+Matches transactions which have been authenticated.
+
+@item @samp{auth _username_ | <username>}
+
+Matches transactions which have been authenticated for user or user list
+username.
+
+@item @samp{helo _helo-name_ | <helo-name>}
+
+Specify that session's HELO / EHLO should match the string or list table
+helo-name.
+
+@item @samp{mail-from _sender_ | <sender>}
+
+Specify that transactions's MAIL FROM should match the string or list
+table sender.
+
+@item @samp{rcpt-to _recipient_ | <recipient>}
+
+Specify that transaction's RCPT TO should match the string or list table
+recipient.
+
+@item @samp{tag tag}
+Matches transactions tagged with the given tag.
+
+@item @samp{tls}
+Specify that transaction should take place in a TLS channel.
+@end itemize
+
+Here is a simple example:
+@lisp
+    (opensmtpd-option-configuration
+     (not #t)
+     (regex #f)
+     (option "for domain")
+     (data (opensmtpd-table-configuration
+            (name "domain-table")
+            (data (list "gnu.org" "dismail.de")))))
+@end lisp
+
+The mail must NOT come from the domains @samp{gnu.org} or @samp{dismail.de}.
+
+@item Data Type: opensmtpd-option-configuration
+@end itemize
+
+@item Data Type: opensmtpd-action-local-delivery-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-action-local-delivery-configuration>} record.
+
+@itemize
+@item
+@code{name} (default: @code{#f})
+
+@code{name} is the string name of the relay action.
+
+@item @code{method} (default: @code{"mbox"})
+
+The email delivery option.  Valid options are:
+
+@itemize
+@item @code{"mbox"}
+
+Deliver the message to the user's mbox with mail.local(8).
+
+@item @code{"expand-only"}
+
+Only accept the message if a delivery method was specified in an aliases
+or .forward file.
+
+@item @code{"forward-only"}
+
+Only accept the message if the recipient results in a remote address after
+the processing of aliases or forward file.
+
+@item @code{<opensmtpd-lmtp-configuration>}
+
+Deliver the message to an LMTP server at
+@code{<opensmtpd-lmtp-configuration>}'s fieldname @code{destination}. The location
+may be expressed as string host:port or as a UNIX socket. Optionally,
+@code{<opensmtpd-lmtp-configuration>}'s fieldname @code{rcpt-to} might be specified
+to use the recipient email address (after expansion) instead of the local
+user in the LMTP session as RCPT TO@.
+
+@item @code{<opensmtpd-maildir-configuration>}
+
+Deliver the message to the maildir in
+@code{<opensmtpd-maildir-configuration>}'s fieldname @code{pathname} if specified,
+or by default to @samp{~/Maildir}.
+
+The pathname may contain format specifiers that are expanded before use
+(see the below section about Format Specifiers).
+
+If @code{<opensmtpd-maildir-configuration>}'s record fieldname @code{junk} is @code{#t},
+then message will be moved to the ‘Junk’ folder if it contains a positive
+‘X-Spam’ header. This folder will be created under fieldname @code{pathname} if
+it does not yet exist.
+
+@item @code{<opensmtpd-mda-configuration>}
+
+Delegate the delivery to the @code{<opensmtpd-mda-configuration>}'s fieldname
+@code{command} (type string) that receives the message on its standard input.
+
+The @code{command} may contain format specifiers that are expanded before use
+(see Format Specifiers).
+@end itemize
+
+@item @code{alias} (default: @code{#f})
+
+Use the mapping table for aliases expansion. @code{alias} is an
+@code{<opensmtpd-table-configuration>}.
+
+@item @code{ttl} (default: @code{#f})
+
+@code{ttl} is a string specify how long a message may remain in the queue.  It's
+format is @samp{n@{s|m|h|d@}}.  eg: ``4m'' is four minutes.
+
+@item @code{user} (default: @code{#f} )
+
+@code{user} is the string username for performing the delivery, to be looked up
+with getpwnam(3).
+
+This is used for virtual hosting where a single username is in charge of
+handling delivery for all virtual users.
+
+This option is not usable with the mbox delivery method.
+
+@item @code{userbase} (default: @code{#f})
+
+@code{userbase} is an @code{<opensmtpd-table-configuration>} record for mapping user
+lookups instead of the getpwnam(3) function.
+
+The fieldnames @code{user} and @code{userbase} are mutually exclusive.
+
+@item @code{virtual} (default: @code{#f})
+
+@code{virtual} is an @code{<opensmtpd-table-configuration>} record is used for virtual
+expansion.
+@end itemize
+
+@item Data Type: opensmtpd-action-relay-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-action-relay-configuration>} record.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+@code{name} is the string name of the relay action.
+
+@item @code{backup} (default: @code{#f})
+
+When @code{#t}, operate as a backup mail exchanger delivering messages to any
+mail exchanger with higher priority.
+
+@item @code{backup-mx} (default: @code{#f})
+
+Operate as a backup mail exchanger delivering messages to any mail exchanger
+with higher priority than mail exchanger identified as string name.
+
+@item @code{helo} (default: @code{#f})
+
+Advertise string heloname as the hostname to other mail exchangers during
+the HELO phase.
+
+@item @code{helo-src} (default: @code{#f} )
+
+ Use the mapping @code{<openmstpd-table-configuration>} to look up a hostname
+matching the source address, to advertise during the HELO phase.
+
+@item @code{domain} (default: @code{#f})
+
+Do not perform MX lookups but look up destination domain in an
+@code{<opensmtpd-table-configuration>} and use matching relay url as relay host.
+
+@item @code{host} (default: @code{#f})
+
+Do not perform MX lookups but relay messages to the relay host described by
+the string relay-url. The format for relay-url is
+@samp{[proto://[label@@]]host[:port]}. The following protocols are available:
+
+@multitable {aaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item smtp
+@tab Normal SMTP session with opportunistic STARTTLS (the default).
+@item smtp+tls
+@tab Normal SMTP session with mandatory STARTTLS@.
+@item smtp+notls
+@tab Plain text SMTP session without TLS@.
+@item lmtp
+@tab LMTP session.  port is required.
+@item smtps
+@tab SMTP session with forced TLS on connection, default port is
+@item
+@tab 465.
+@end multitable
+
+Unless noted, port defaults to 25.
+
+The label corresponds to an entry in a credentials table, as documented in
+@samp{table(5)}. It is used with the @samp{"smtp+tls"} and @samp{"smtps"} protocols for
+authentication. Server certificates for those protocols are verified by
+default.
+
+@item @code{pki} (default: @code{#f})
+
+For secure connections, use the certificate associated with
+@code{<opensmtpd-pki-configuration>} (declared in a pki directive) to prove the
+client's identity to the remote mail server.
+
+@item @code{srs} (default: @code{#f})
+
+If @code{#t}, then when relaying a mail resulting from a forward, use the Sender
+Rewriting Scheme to rewrite sender address.
+
+@item @code{tls} (default: @code{#f}) boolean or string ``no-verify''
+
+When @code{#t}, Require TLS to be used when relaying, using mandatory STARTTLS by
+default. When used with a smarthost, the protocol must not be
+@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not require a valid
+certificate.
+
+@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table-configuration>}
+
+Use the alist @code{<opensmtpd-table-configuration>} for connecting to relay-url
+using credentials. This option is usable only with fieldname @code{host} option.
+
+@item @code{mail-from} (default: @code{#f}) string
+
+Use the string mailaddress as MAIL FROM address within the SMTP transaction.
+
+@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-table-configuration>}
+
+Use the string or @code{<opensmtpd-table-configuration>} sourceaddr for the
+source IP address, which is useful on machines with multiple interfaces. If
+the list contains more than one address, all of them are used in such a way
+that traffic is routed as efficiently as possible.
+@end itemize
+
+@item Data Type: opensmtpd-filter-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-filter-configuration>}. This is the filter record one should use
+if they want to use an external package to filter email eg: rspamd or
+spamassassin.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+The string name of the filter.
+
+@item @code{proc} (default: @code{#f})
+
+The string command or process name.  If @code{proc-exec} is @code{#t}, @code{proc} is
+treated as a command to execute.  Otherwise, it is a process name.
+
+@item @code{proc-exec} (default: @code{#f})
+@end itemize
+
+@item Data Type: opensmtpd-filter-phase-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-filter-phase-configuration>}.
+
+In a regular workflow, smtpd(8) may accept or reject a message based only on
+the content of envelopes. Its decisions are about the handling of the message,
+not about the handling of an active session.
+
+Filtering extends the decision making process by allowing smtpd(8) to stop at
+each phase of an SMTP session, check that options are met, then decide if a
+session is allowed to move forward.
+
+With filtering via an @code{<opensmtpd-filter-phase-configuration>} record, a
+session may be interrupted at any phase before an envelope is complete. A
+message may also be rejected after being submitted, regardless of whether the
+envelope was accepted or not.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+The string name of the filter phase.
+
+@item @code{phase-name} (default: @code{#f})
+
+The string name of the phase. Valid values are:
+
+@multitable {aaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``connect''
+@tab upon connection, before a banner is displayed
+@item ``helo''
+@tab after HELO command is submitted
+@item ``ehlo''
+@tab after EHLO command is submitted
+@item ``mail-from''
+@tab after MAIL FROM command is submitted
+@item ``rcpt-to''
+@tab after RCPT TO command is submitted
+@item ``data''
+@tab after DATA command is submitted
+@item ``commit''
+@tab after message is fully is submitted
+@end multitable
+
+@item @code{options} (default @code{#f})
+
+A list of unique @code{<opensmtpd-option-configuration>} records.
+
+At each phase, various options, specified by a list of
+@code{<opensmtpd-option-configuration>}, may be checked. The
+@code{<opensmtpd-option-configuration>}'s fieldname 'option' values of: ``fcrdns'',
+``rdns'', and ``src'' data are available in all phases, but other data must have
+been already submitted before they are available. Options with a @samp{<table>}
+next to them require the @code{<opensmtpd-option-configuration>}'s fieldname
+@code{data} to be an @code{<opensmtpd-table-configuration>}. There are the available
+options:
+
+@multitable {aaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item fcrdns
+@tab forward-confirmed reverse DNS is valid
+@item rdns
+@tab session has a reverse DNS
+@item rdns <table>
+@tab session has a reverse DNS in table
+@item src <table>
+@tab source address is in table
+@item helo <table>
+@tab helo name is in table
+@item auth
+@tab session is authenticated
+@item auth <table>
+@tab session username is in table
+@item mail-from <table>
+@tab sender address is in table
+@item rcpt-to <table>
+@tab recipient address is in table
+@end multitable
+
+These conditions may all be negated by setting
+@code{<opensmtpd-option-configuration>}'s fieldname @code{not} to @code{#t}.
+
+Any conditions that require a table may indicate that tables include regexs
+setting @code{<opensmtpd-option-configuration>}'s fieldname @code{regex} to @code{#t}.
+
+@item @code{decision}
+
+A string decision to be taken. Some decisions require an @code{message} or
+@code{value}. Valid strings are:
+
+@multitable {aaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``bypass''
+@tab the session or transaction bypasses filters
+@item ``disconnect'' message
+@tab the session is disconnected with message
+@item ``junk''
+@tab the session or transaction is junked, i.e., an
+@item
+@tab ‘X-Spam: yes’ header is added to any messages
+@item ``reject'' message
+@tab the command is rejected with message
+@item ``rewrite'' value
+@tab the command parameter is rewritten with value
+@end multitable
+
+Decisions that involve a message require that the message be RFC valid,
+meaning that they should either start with a 4xx or 5xx status code.
+Descisions can be taken at any phase, though junking can only happen before
+a message is committed.
+
+@item @code{message} (default @code{#f})
+
+A string message beginning with a 4xx or 5xx status code.
+
+@item @code{value} (default: @code{#f})
+
+A number value.  @code{value} and @code{message} are mutually exclusive.
+@end itemize
+
+@item Data Type: opensmtpd-option-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-option-configuration>}, which is used by
+@code{<opensmtpd-filter-phase-configuration>} and @code{<opensmtpd-match-configuration>}
+to match various options for email.
+
+@itemize
+@item @code{conditition} (default @code{#f})
+
+A string option to be taken. Some options require a string or an
+@code{<opensmtpd-table-configuration>} via the fieldname data. When the option
+record is used inside of an @code{<opensmtpd-filter-phase-configuration>}, then
+valid strings are:
+
+At each phase, various options may be matched. The fcrdns, rdns, and src
+data are available in all phases, but other data must have been already
+submitted before they are available.
+
+@multitable {aaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``fcrdns''
+@tab forward-confirmed reverse DNS is valid
+@item ``rdns''
+@tab session has a reverse DNS
+@item ``rdns'' <table>
+@tab session has a reverse DNS in table
+@item ``src'' <table>
+@tab source address is in table
+@item ``helo'' <table>
+@tab helo name is in table
+@item ``auth''
+@tab session is authenticated
+@item ``auth'' <table>
+@tab session username is in table
+@item ``mail-from'' <table>
+@tab sender address is in table
+@item ``rcpt-to'' <table>
+@tab recipient address is in table
+@end multitable
+
+When @code{<opensmtpd-option-configuration>} is used inside of an
+@code{<opensmtpd-match-configuration>}, then valid strigs for fieldname @code{option}
+are: ``for'', ``for any'', ``for local'', ``for domain'', ``for rcpt-to'', ``from any''
+``from auth'', ``from local'', ``from mail-from'', ``from rdns'', ``from socket'',
+``from src'', ``auth'', ``helo'', ``mail-from'', ``rcpt-to'', ``tag'', or ``tls''.
+
+@item @code{data} (default @code{#f}) @code{<opensmtpd-table-configuration>}
+
+Some options require a table to be present. One would specify that table
+here.
+@item @code{regex} (default: @code{#f}) boolean
+
+Any options using a table may indicate that tables hold regex by
+prefixing the table name with the keyword regex.
+
+@item @code{not} (default: @code{#f}) boolean
+
+When @code{#t}, this option record is negated.
+@end itemize
+
+@item Data Type: opensmtpd-table-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-table-configuration>}.
+
+@itemize
+@item @code{name} (default @code{#f})
+
+@code{name} is the name of the @code{<opensmtpd-table-configuration>} record.
+
+@item @code{data} (default: @code{#f})
+
+@code{data} expects a list of strings or an alist, which is a list of
+cons cells.  eg: @code{(data (list ("james" . "password")))} OR
+@code{(data (list ("gnu.org" "fsf.org")))}.
+@end itemize
+
+@item Data Type: opensmtpd-pki-configuration
+
+This data type represents the configuration of an
+@code{<opensmtpd-pki-configuration>}.
+
+@itemize
+@item @code{domain} (default @code{#f})
+
+@code{domain} is the string name of the @code{<opensmtpd-pki-configuration>} record.
+
+@item @code{cert} (default: @code{#f})
+
+@code{cert} (default: @code{#f})
+
+@code{cert} is the string certificate filename to use for this pki.
+
+@item @code{key} (default: @code{#f})
+
+@code{key} is the string certificate falename to use for this pki.
+
+@item @code{dhe} (default: @code{"none"})
+
+Specify the DHE string parameter to use for DHE cipher suites with host
+pkiname. Valid parameter values are ``none'', ``legacy'', or ``auto''. For ``legacy'', a
+fixed key length of 1024 bits is used, whereas for ``auto'', the key length is
+determined automatically. The default is ``none'', which disables DHE cipher
+suites.
+@end itemize
+
+@item Data Type: opensmtpd-maildir-configuration
+
+@itemize
+@item @code{pathname} (default: @code{"~/Maildir"})
+
+Deliver the message to the maildir if pathname if specified, or by default
+to @samp{~/Maildir}.
+
+The pathname may contain format specifiers that are expanded before use
+(see FORMAT SPECIFIERS).
+
+@item @code{junk} (default: @code{#f})
+
+If the junk argument is @code{#t}, then the message will be moved to the @samp{‘Junk’}
+folder if it contains a positive @samp{‘X-Spam’} header. This folder will be
+created under pathname if it does not yet exist.
+@end itemize
+
+@item Data Type: opensmtpd-mda-configuration
+
+@itemize
+@item @code{name}
+
+The string name for this MDA command.
+
+@item @code{command}
+
+Delegate the delivery to a command that receives the message on its standard
+input.
+
+The command may contain format specifiers that are expanded before use (see
+FORMAT SPECIFIERS).
+@end itemize
+
+@item Data Type: opensmtpd-queue-configuration
+
+@itemize
+@item @code{compression} (default @code{#f})
+
+Store queue files in a compressed format. This may be useful to save disk
+space.
+
+@item @code{encryption} (default @code{#f})
+
+Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If no key is specified, it is
+read with getpass(3). If the string stdin or a single dash (‘-’) is given
+instead of a key, the key is read from the standard input.
+
+@item @code{ttl-delay} (default @code{#f})
+
+Set the default expiration time for temporarily undeliverable messages,
+given as a positive decimal integer followed by a unit s, m, h, or d. The
+default is four days (``4d'').
+@end itemize
+
+@item Data Type: opensmtpd-smtp-configuration
+
+Data type representing an @code{<opensmtpd-smtp-configuration>} record.
+
+@itemize
+@item @code{ciphers} (default: @code{#f})
+
+Set the control string for SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default is
+         ``HIGH:!aNULL:!MD5''.
+
+@item @code{limit-max-mails} (default: @code{100})
+
+Limit the number of messages to count for each sessio
+
+@item @code{limit-max-rcpt} (default: @code{1000})
+
+Limit the number of recipients to count for each transaction.
+
+@item @code{max-message-size} (default: @code{35M})
+
+Reject messages larger than size, given as a positive number of bytes or as
+a string to be parsed with scan@math{_scaled}(3).
+
+@item @code{sub-addr-delim character} (default: @code{+})
+
+When resolving the local part of a local email address, ignore the ASCII
+character and all characters following it. This is helpful for email
+filters. @samp{"admin+bills@@gnu.org"} is the same email address as
+@samp{"admin@@gnu.org"}. BUT an email filter can filter emails addressed to first
+email address into a 'Bills' email folder.
+@end itemize
+
+@item Data Type: opensmtpd-srs-configuration
+
+@itemize
+@item @code{key} (default: @code{#f})
+
+Set the secret key to use for SRS, the Sender Rewriting Scheme.
+
+@item @code{backup-key} (default: @code{#f})
+
+Set a backup secret key to use as a fallback for SRS@. This can be used to
+implement SRS key rotation.
+
+@item @code{ttl-delay} (default: @code{"4d"})
+
+Set the time-to-live delay for SRS envelopes. After this delay, a bounce
+reply to the SRS address will be discarded to limit risks of forged
+addresses.
+@end itemize
+
+@item Format Specifiers
+
+Some configuration records support expansion of their parameters at
+runtime. Such records (for example
+@code{<opensmtpd-maildir-configuration>}, @code{<opensmtpd-mda-configuration>}) may use
+format specifiers which are expanded before delivery or relaying. The
+following formats are currently supported:
+
+@multitable {aaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{sender@}}
+@tab sender email address, may be empty string
+@item @samp{%@{sender.user@}}
+@tab user part of the sender email address, may be empty
+@item @samp{%@{sender.domain@}}
+@tab domain part of the sender email address, may be empty
+@item @samp{%@{rcpt@}}
+@tab recipient email address
+@item @samp{%@{rcpt.user@}}
+@tab user part of the recipient email address
+@item @samp{%@{rcpt.domain@}}
+@tab domain part of the recipient email address
+@item @samp{%@{dest@}}
+@tab recipient email address after expansion
+@item @samp{%@{dest.user@}}
+@tab user part after expansion
+@item @samp{%@{dest.domain@}}
+@tab domain part after expansion
+@item @samp{%@{user.username@}}
+@tab local user
+@item @samp{%@{user.directory@}}
+@tab home directory of the local user
+@item @samp{%@{mbox.from@}}
+@tab name used in mbox From separator lines
+@item @samp{%@{mda@}}
+@tab mda command, only available for mda wrappers
+@end multitable
+
+Expansion formats also support partial expansion using the optional bracket notations
+with substring offset.  For example, with recipient domain @samp{“example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt.domain[0]@}}
+@tab expands to “e”
+@item @samp{%@{rcpt.domain[1]@}}
+@tab expands to “x”
+@item @samp{%@{rcpt.domain[8:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[-3:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[0:6]@}}
+@tab expands to “example”
+@item @samp{%@{rcpt.domain[0:-4]@}}
+@tab expands to “example”
+@end multitable
+
+In addition, modifiers may be applied to the token.  For example, with recipient
+@samp{“User+Tag@@Example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt:lowercase@}}
+@tab expands to “user+tag@@example.org”
+@item @samp{%@{rcpt:uppercase@}}
+@tab expands to “USER+TAG@@EXAMPLE.ORG”
+@item @samp{%@{rcpt:strip@}}
+@tab expands to “User@@Example.org”
+@item @samp{%@{rcpt:lowercasestrip@}}
+@tab expands to “user@@example.org”
+@end multitable
+
+For security concerns, expanded values are sanitized and potentially dangerous
+characters are replaced with ‘:’. In situations where they are desirable, the
+“raw” modifier may be applied. For example, with recipient
+@samp{“user+t?g@@example.org”}:
+
+@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt@}}
+@tab expands to “user+t:g@@example.org”
+@item @samp{%@{rcpt:raw@}}
+@tab expands to “user+t?g@@example.org”
+@end multitable
+@end itemize
+
 @subsubheading Exim Service
 
 @cindex mail transfer agent (MTA)
diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index d99743ac31..2a344e303e 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -57,8 +57,143 @@ (define-module (gnu services mail)
             mailbox-configuration
             namespace-configuration
 
+            opensmtpd-table-configuration
+            opensmtpd-table-configuration?
+            opensmtpd-table-configuration-name
+            opensmtpd-table-configuration-file-db
+            opensmtpd-table-configuration-data
+
+            opensmtpd-ca-configuration
+            opensmtpd-ca-configuration?
+            opensmtpd-ca-configuration-name
+            opensmtpd-ca-configuration-file
+
+            opensmtpd-pki-configuration
+            opensmtpd-pki-configuration?
+            opensmtpd-pki-configuration-domain
+            opensmtpd-pki-configuration-cert
+            opensmtpd-pki-configuration-key
+            opensmtpd-pki-configuration-dhe
+
+            opensmtpd-action-local-delivery-configuration
+            opensmtpd-action-local-delivery-configuration?
+            opensmtpd-action-local-delivery-configuration-method
+            opensmtpd-action-local-delivery-configuration-alias
+            opensmtpd-action-local-delivery-configuration-ttl
+            opensmtpd-action-local-delivery-configuration-user
+            opensmtpd-action-local-delivery-configuration-userbase
+            opensmtpd-action-local-delivery-configuration-virtual
+            opensmtpd-action-local-delivery-configuration-wrapper
+
+            opensmtpd-maildir-configuration
+            opensmtpd-maildir-configuration?
+            opensmtpd-maildir-configuration-pathname
+            opensmtpd-maildir-configuration-junk
+
+            opensmtpd-mda-configuration
+            opensmtpd-mda-configuration-name
+            opensmtpd-mda-configuration-command
+
+            opensmtpd-action-relay-configuration
+            opensmtpd-action-relay-configuration?
+            opensmtpd-action-relay-configuration-backup
+            opensmtpd-action-relay-configuration-backup-mx
+            opensmtpd-action-relay-configuration-helo
+            opensmtpd-action-relay-configuration-domain
+            opensmtpd-action-relay-configuration-host
+            opensmtpd-action-relay-configuration-pki
+            opensmtpd-action-relay-configuration-srs
+            opensmtpd-action-relay-configuration-tls
+            opensmtpd-action-relay-configuration-auth
+            opensmtpd-action-relay-configuration-mail-from
+            opensmtpd-action-relay-configuration-src
+
+            opensmtpd-option-configuration
+            opensmtpd-option-configuration?
+            opensmtpd-option-configuration-option
+            opensmtpd-option-configuration-not
+            opensmtpd-option-configuration-regex
+            opensmtpd-option-configuration-data
+
+            opensmtpd-filter-phase-configuration
+            opensmtpd-filter-phase-configuration?
+            opensmtpd-filter-phase-configuration-name
+            opensmtpd-filter-phase-configuration-phase-name
+            opensmtpd-filter-phase-configuration-options
+            opensmtpd-filter-phase-configuration-decision
+            opensmtpd-filter-phase-configuration-message
+            opensmtpd-filter-phase-configuration-value
+
+            opensmtpd-filter-configuration
+            opensmtpd-filter-configuration?
+            opensmtpd-filter-configuration-name
+            opensmtpd-filter-configuration-proc
+
+            opensmtpd-listen-on-configuration
+            opensmtpd-listen-on-configuration?
+            opensmtpd-listen-on-configuration-interface
+            opensmtpd-listen-on-configuration-family
+            opensmtpd-listen-on-configuration-auth
+            opensmtpd-listen-on-configuration-auth-optional
+            opensmtpd-listen-on-configuration-filters
+            opensmtpd-listen-on-configuration-hostname
+            opensmtpd-listen-on-configuration-hostnames
+            opensmtpd-listen-on-configuration-mask-src
+            opensmtpd-listen-on-configuration-disable-dsn
+            opensmtpd-listen-on-configuration-pki
+            opensmtpd-listen-on-configuration-port
+            opensmtpd-listen-on-configuration-proxy-v2
+            opensmtpd-listen-on-configuration-received-auth
+            opensmtpd-listen-on-configuration-senders
+            opensmtpd-listen-on-configuration-secure-connection
+            opensmtpd-listen-on-configuration-tag
+
+            opensmtpd-listen-on-socket-configuration
+            opensmtpd-listen-on-socket-configuration?
+            opensmtpd-listen-on-socket-configuration-filters
+            opensmtpd-listen-on-socket-configuration-mask-src
+            opensmtpd-listen-on-socket-configuration-tag
+
+            opensmtpd-match-configuration
+            opensmtpd-match-configuration?
+            opensmtpd-match-configuration-action
+            opensmtpd-match-configuration-options
+
+            opensmtpd-smtp-configuration
+            opensmtpd-smtp-configuration?
+            opensmtpd-smtp-configuration-ciphers
+            opensmtpd-smtp-configuration-limit-max-mails
+            opensmtpd-smtp-configuration-limit-max-rcpt
+            opensmtpd-smtp-configuration-max-message-size
+            opensmtpd-smtp-configuration-sub-addr-delim character
+
+            opensmtpd-srs-configuration
+            opensmtpd-srs-configuration?
+            opensmtpd-srs-configuration-key
+            opensmtpd-srs-configuration-backup-key
+            opensmtpd-srs-configuration-ttl-delay
+
+            opensmtpd-queue-configuration
+            opensmtpd-queue-configuration?
+            opensmtpd-queue-configuration-compression
+            opensmtpd-queue-configuration-encryption
+            opensmtpd-queue-configuration-ttl-delay
+
             opensmtpd-configuration
             opensmtpd-configuration?
+            opensmtpd-package
+            opensmtpd-config-file
+            opensmtpd-configuration-bounce
+            opensmtpd-configuration-listen-ons
+            opensmtpd-configuration-listen-on-socket
+            opensmtpd-configuration-includes
+            opensmtpd-configuration-matches
+            opensmtpd-configuration-mda-wrappers
+            opensmtpd-configuration-mta-max-deferred
+            opensmtpd-configuration-srs
+            opensmtpd-configuration-smtp
+            opensmtpd-configuration-queue
+
             opensmtpd-service-type
             %default-opensmtpd-config-file
 
@@ -1651,13 +1786,1888 @@ (define (generate-dovecot-documentation)
 ;;; OpenSMTPD.
 ;;;
 
+;; some fieldnames have a default value of #f, which is ok.  They cannot have a value of #t.
+;; for example opensmtpd-table-configuration-data can be #f, BUT NOT true.
+;; my/sanitize procedure tests values to see if they are of the right kind.
+;; procedure false? is needed to allow fields like 'values' to be blank, (empty), or #f BUT also
+;; have a value like a list of strings.
+(define (false? var)
+  (eq? #f var))
+
+;; this procedure takes in a var and a list of procedures.  It loops through list of procedures passing in var to each.
+;; if one procedure returns #t, the function returns true.  Otherwise #f.
+;; TODO for fun rewrite this using map
+;; If I rewrote it in map, then it may help with sanitizing.
+;; eg: I could then potentially easily sanitize vars with lambda procedures.
+(define (is-value-right-type? var list-of-procedures record fieldname)
+  (if (null? list-of-procedures)
+        #f
+        (cond [(procedure? (car list-of-procedures))
+               (if ((car list-of-procedures) var)
+                   #t
+                   (is-value-right-type? var (cdr list-of-procedures) record fieldname))]
+              [(and (sanitize-configuration? (car list-of-procedures))
+                    (sanitize-configuration-error-if-proc-fails (car list-of-procedures))
+                    (if ((sanitize-configuration-proc (car list-of-procedures)) var)
+                        #t
+                        (begin
+                          (apply string-append
+                                 (sanitize-configuration-error-message (car list-of-procedures)))
+                          (throw 'bad! var))))]
+              [else (if ((sanitize-configuration-proc (car list-of-procedures)) var)
+                        #t
+                        (is-value-right-type? var (cdr list-of-procedures) record fieldname))])))
+
+;; converts strings like this:
+;; "apple, ham, cherry" -> "apple, ham, or cherry"
+;; "pineapple" -> "pinneapple".
+;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
+(define (add-comma-or string)
+  (define last-comma-location (string-rindex string #\,))
+  (if last-comma-location
+      (if (string-contains string ", or" last-comma-location)
+          string
+          (string-replace string ", or" last-comma-location
+                          (+ 1 last-comma-location)))
+      string))
+
+;; I could test for read-ability of a file, but then I would have to
+;; test the program as root everytime instead of as a normal user...
+(define (file-exists? file)
+(if (string? file)
+    (access? file F_OK)
+    #f))
+
+(define (list-of-procedures->string procedures)
+  (define string
+    (let loop ([procedures procedures])
+      (if (null? procedures)
+          ""
+          (begin
+            (string-append
+             (cond [(eq? false? (car procedures))
+                    "#f , "]
+                   [(eq? boolean? (car procedures))
+                    "boolean, "]
+                   [(eq? string? (car procedures))
+                    "string, "]
+                   [(eq? integer? (car procedures))
+                    "integer, "]
+                   [(eq? list-of-strings? (car procedures))
+                    "list of strings, "]
+                   [(eq? assoc-list? (car procedures))
+                    "an association list, "]
+                   [(eq? opensmtpd-pki-configuration? (car procedures))
+                    "an <opensmtpd-pki-configuration> record, "]
+                   [(eq? opensmtpd-table-configuration? (car procedures))
+                    "an <opensmtpd-table-configuration> record, "]
+                   [(eq? list-of-unique-opensmtpd-match-configuration? (car procedures))
+                    "a list of unique <opensmtpd-match-configuration> records, "]
+                   [(eq? table-whose-data-are-assoc-list? (car procedures))
+                    (string-append
+                    "an <opensmtpd-table-configuration> record whose fieldname 'values' are an assoc-list \n"
+                    "(eg: (opensmtpd-table-configuration (name \"table\") (data '(\"joshua\" . \"$encrypted$password\")))), ")]
+                   [(eq? file-exists? (car procedures))
+                    "file, "]
+                   [else "has an incorrect value, "])
+             (loop (cdr procedures)))))))
+  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
+
+;; TODO can I M-x raise-sexp (string=? string var) in this procedure? and get rid of checking
+;; if the var is a string?  The previous string-in-list? had that check.
+;; (string-in-list? '("hello" 5 "cat")) currently works.  If I M-x raise-sexp (string=? string var)
+;; then it will no longer work.
+(define (string-in-list? string list)
+  (primitive-eval (cons 'or (map (lambda (var) (and (string? var) (string=? string var))) list))))
+
+(define (my/sanitize var record fieldname list-of-procedures)
+  (if (is-value-right-type? var list-of-procedures record fieldname)
+      var
+      (begin
+        (display (string-append "<" record "> fieldname: '" fieldname "' is of type "
+                                (list-of-procedures->string list-of-procedures) "\n"))
+        (throw 'bad! var))))
+
+;; Some example opensmtpd-table-configurations:
+;;
+;;  (opensmtpd-table-configuration (name "root accounts") (data '(("joshua" . "root@dismail.de") ("joshua" . "postmaster@dismail.de"))))
+;;  (opensmtpd-table-configuration (name "root accounts") (data (list "mysite.me" "your-site.com")))
+;;  TODO should <opensmtpd-table-configuration> support have a fieldname 'file'?
+;;  Or should I change name to name-or-file ?
+(define-record-type* <opensmtpd-table-configuration>
+  opensmtpd-table-configuration make-opensmtpd-table-configuration
+  opensmtpd-table-configuration?
+  this-record
+  (name opensmtpd-table-configuration-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table-configuration" "name" (list string?)))))
+  (file-db opensmtpd-table-configuration-file-db
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-table-configuration" "file-db"
+                                    (list boolean?)))))
+  ;; FIXME support an aliasing table as described here:
+  ;; https://man.openbsd.org/table.5
+  ;; One may have to use the record file for this.  I don't think tables support a table like this:
+  ;; table "name" { joshua = joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root = root@gnucode.me }
+  ;; If values is an absolute filename, then it will use said filename to house the table info.
+  ;; filename must be an absolute filename.
+  (data opensmtpd-table-configuration-data
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-table-configuration" "values"
+                                   (list file-exists? list-of-strings? assoc-list?)))))
+  ;; is a list of values or key values
+  ;; eg: (list "mysite.me" "your-site.com")
+  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" . "james@gnu.org"))
+  ;; I am currently making these values be as assocation list of strings only.
+  ;; FIXME should I allow a var like this?
+  ;; (list (cons "gnucode.me" 234.949.392.23))
+  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
+  ;; (opensmtpd-table-configuration-type record) returns the values' type.  The user SHOULD NEVER set the type.
+  ;; TODO jpoiret: on irc reccomends that I just use an outside function to determine fieldname 'values', type.
+  ;; it would be "simpler" and possibly easier for the next person working on this code to understand what is happening.
+  (type opensmtpd-table-configuration-type
+        (default #f)
+        (thunked)
+        (sanitize (lambda (var)
+                    (cond [(opensmtpd-table-configuration-data this-record)
+                           (if (list-of-strings? (opensmtpd-table-configuration-data this-record))
+                               (quote list-of-strings)
+                               (quote assoc-list))]
+                          [(file-exists? (opensmtpd-table-configuration-data this-record))
+                           (if (opensmtpd-table-configuration-file-db this-record)
+                               (quote db)
+                               (quote file))]
+                          [else
+                           (display "opensmtpd-table-configuration-type is broke\n")
+                           (throw 'bad! var)])))))
+
+(define-record-type* <opensmtpd-ca-configuration>
+  opensmtpd-ca-configuration make-opensmtpd-ca-configuration
+  opensmtpd-ca-configuration?
+  (name opensmtpd-ca-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca-configuration" "name" (list string?)))))
+  (file opensmtpd-ca-configuration-file
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca-configuration" "file" (list file-exists?))))))
+
+(define-record-type* <opensmtpd-pki-configuration>
+  opensmtpd-pki-configuration make-opensmtpd-pki-configuration
+  opensmtpd-pki-configuration?
+  (domain opensmtpd-pki-configuration-domain
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-pki-configuration" "domain" (list string?)))))
+  ;; TODO/FIXME this should probably be a list of files.  The opensmtpd documentation says
+  ;; that you could have a list of files:
+  ;;
+  ;; pki pkiname cert certfile
+  ;; Associate certificate file certfile with host pkiname, and use that file to prove
+  ;; the identity of the mail server to clients.  pkiname is the server's name, de‐
+  ;; rived from the default hostname or set using either
+  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/mailname or us‐
+  ;; ing the hostname directive.  If a fallback certificate or SNI is wanted, the ‘*’
+  ;; wildcard may be used as pkiname.
+
+  ;; A certificate chain may be created by appending one or many certificates, includ‐
+  ;; ing a Certificate Authority certificate, to certfile.  The creation of certifi‐
+  ;; cates is documented in starttls(8).
+  (cert opensmtpd-pki-configuration-cert
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-pki-configuration" "cert" (list file-exists?)))))
+  (key opensmtpd-pki-configuration-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-pki-configuration" "key" (list file-exists?)))))
+  ; todo sanitize this. valid parameters are "none", "legacy", or "auto".
+  (dhe opensmtpd-pki-configuration-dhe
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-dhe" "dhe" (list false? string?))))))
+
+(define-record-type* <opensmtpd-lmtp-configuration>
+  opensmtpd-lmtp-configuration make-opensmtpd-lmtp-configuration
+  opensmtpd-lmtp-configuration?
+  (destination opensmtpd-lmtp-configuration-destination
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-lmtp-configuration" "destination"
+                                        (list string?)))))
+  (rcpt-to opensmtpd-lmtp-configuration-rcpt-to
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-lmtp-configuration" "rcpt-to"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-mda-configuration>
+  opensmtpd-mda-configuration make-opensmtpd-mda-configuration
+  opensmtpd-mda-configuration?
+  (name opensmtpd-mda-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-mda-configuration" "name"
+                                 (list string?)))))
+  ;; TODO should I allow this command to be a gexp?
+  (command opensmtpd-mda-configuration-command
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-mda-configuration" "command"
+                                    (list string?))))))
+
+(define-record-type* <opensmtpd-maildir-configuration>
+  opensmtpd-maildir-configuration make-opensmtpd-maildir-configuration
+  opensmtpd-maildir-configuration?
+  (pathname opensmtpd-maildir-configuration-pathname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-maildir-configuration" "pathname"
+                                     (list false? string?)))))
+  (junk opensmtpd-maildir-configuration-junk
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-maildir-configuration" "junk"
+                                 (list boolean?))))))
+
+(define-record-type* <opensmtpd-action-local-delivery-configuration>
+  opensmtpd-action-local-delivery-configuration make-opensmtpd-action-local-delivery-configuration
+  opensmtpd-action-local-delivery-configuration?
+  (name opensmtpd-action-local-delivery-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-local-delivery-configuration" "name"
+                                 (list string?)))))
+  (method opensmtpd-action-local-delivery-configuration-method
+          (default "mbox")
+          (sanitize (lambda (var)
+                      (cond
+                       [(or (opensmtpd-lmtp-configuration? var)
+                            (opensmtpd-maildir-configuration? var)
+                            (opensmtpd-mda-configuration? var)
+                            (string=? var "mbox")
+                            (string=? var "expand-only")
+                            (string=? var "forward-only"))
+                        var]
+                       [else
+                        (begin
+                          (display (string-append "<opensmtpd-action-local-delivery-configuration> fieldname 'method' must be of type \n"
+                                                  "\"mbox\", \"expand-only\", \"forward-only\" \n"
+                                                  "<opensmtpd-lmtp-configuration>, <opensmtpd-maildir-configuration>, \n"
+                                                  "or <opensmtpd-mda-configuration>.\n"))
+                          (throw 'bad! var))]))))
+  (alias opensmtpd-action-local-delivery-configuration-alias
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-action-local-delivery-configuration" "alias"
+                                  (list false? opensmtpd-table-configuration?)))))
+  (ttl opensmtpd-action-local-delivery-configuration-ttl
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-local-delivery-configuration" "ttl"
+                                (list false? string?)))))
+  (user opensmtpd-action-local-delivery-configuration-user
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-local-delivery-configuration" "user"
+                                 (list false? string?)))))
+  (userbase opensmtpd-action-local-delivery-configuration-userbase
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-action-local-delivery-configuration" "userbase"
+                                     (list false? opensmtpd-table-configuration?)))))
+  (virtual opensmtpd-action-local-delivery-configuration-virtual
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-action-local-delivery-configuration" "virtual"
+                                    (list false? opensmtpd-table-configuration?)))))
+  (wrapper opensmtpd-action-local-delivery-configuration-wrapper
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-action-local-delivery-configuration" "wrapper"
+                                    (list false? string?))))))
+
+;; FIXME/TODO this is a valid opensmtpd-relay record
+;; (opensmtpd-action-relay-configuration
+;;  (pki (opensmtpd-pki-configuration
+;;        (domain "gnucode.me")
+;;        (cert "opensmtpd.scm")
+;;        (key "opensmtpd.scm"))))
+;; BUT how does it relay the email?  What host does it use?
+;; I think opensmtpd-relay-configuration needs "method" field.
+;; the method field might need to be another record...BUT basically the relay has to have a 'backup', 'backup-mx',
+;; or 'domain', or 'host' defined.
+(define-record-type* <opensmtpd-action-relay-configuration>
+  opensmtpd-action-relay-configuration make-opensmtpd-action-relay-configuration
+  opensmtpd-action-relay-configuration?
+  (name opensmtpd-action-relay-configuration-name
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "name"
+                                 (list string?))))
+        (default #f))
+  (backup opensmtpd-action-relay-configuration-backup ;; boolean
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "backup"
+                                   (list boolean?)))))
+  (backup-mx opensmtpd-action-relay-configuration-backup-mx ;; string mx name
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-action-relay-configuration" "backup-mx"
+                                      (list false? string?)))))
+  (helo opensmtpd-action-relay-configuration-helo
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "helo"
+                                 (list false? string? opensmtpd-table-configuration?))))
+        (default #f))
+  (helo-src opensmtpd-action-relay-configuration-helo-src
+        (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "helo-src"
+                                   (list false? string? opensmtpd-table-configuration?))))
+        (default #f))
+  (domain opensmtpd-action-relay-configuration-domain
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-action-relay-configuration" "domain"
+                                   (list false? opensmtpd-table-configuration?))))
+          (default #f))
+  (host opensmtpd-action-relay-configuration-host
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "host"
+                                 (list false? string?))))
+        (default #f))
+  (pki opensmtpd-action-relay-configuration-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "pki"
+                                (list false? opensmtpd-pki-configuration?)))))
+  (srs opensmtpd-action-relay-configuration-srs
+       (default #f)
+       (lambda (var)
+         (my/sanitize var "opensmtpd-action-relay-configuration" "srs"
+                      (list boolean?))))
+  (tls opensmtpd-action-relay-configuration-tls
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "tls"
+                                (list false? string?)))))
+  (auth opensmtpd-action-relay-configuration-auth
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-action-relay-configuration" "auth"
+                                 (list false? opensmtpd-table-configuration?))))
+        (default #f))
+  (mail-from opensmtpd-action-relay-configuration-mail-from
+             (default #f))
+  ;; string "127.0.0.1" or "<interface>" or "<table of IP addresses>"
+  ;; TODO should I do some sanitizing to make sure that the string? here is actually an IP address or a valid interface?
+  (src opensmtpd-action-relay-configuration-src
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-action-relay-configuration" "src"
+                                (list false? string? opensmtpd-table-configuration?))))
+       (default #f)))
+
+;; this record is used by <opensmtpd-filter-phase-configuration> &
+;; <opensmtpd-match-configuration>
+(define-record-type* <opensmtpd-option-configuration>
+  opensmtpd-option-configuration make-opensmtpd-option-configuration
+  opensmtpd-option-configuration?
+  (option opensmtpd-option-configuration-option
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (and (string? var)
+                               (or (string-in-list? var (list "fcrdns" "rdns"
+                                                          "src" "helo"
+                                                          "auth" "mail-from"
+                                                          "rcpt-to"
+                                                          "for"
+                                                          "for any" "for local"
+                                                          "for domain" "for rcpt-to"
+                                                          "from any" "from auth"
+                                                          "from local" "from mail-from"
+                                                          "from rdns" "from socket"
+                                                          "from src" "auth"
+                                                          "helo" "mail-from"
+                                                          "rcpt-to" "tag" "tls"
+                                                          ))))
+                          var
+                          (begin
+                            (display (string-append "<opensmtpd-option-configuration> fieldname: 'option' is of type \n"
+                                                    "string.  The string can be either 'fcrdns', \n"
+                                                    " 'rdns', 'src', 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
+                                                    "'for', 'for any', 'for local', 'for domain', 'for rcpt-to', \n"
+                                                    "'from any', 'from auth', 'from local', 'from mail-from', 'from rdns', 'from socket', \n"
+                                                    "'from src', 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"
+                                                    ))
+                            (throw 'bad! var))))))
+  (not opensmtpd-option-configuration-not
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-option-configuration" "not"
+                                (list boolean?)))))
+  (regex opensmtpd-option-configuration-regex
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option-configuration" "regex"
+                                  (list boolean?)))))
+  (data opensmtpd-option-configuration-data
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option-configuration" "data"
+                                  (list false? string? opensmtpd-table-configuration?))))))
+
+(define-record-type* <opensmtpd-filter-phase-configuration>
+  opensmtpd-filter-phase-configuration make-opensmtpd-filter-phase-configuration
+  opensmtpd-filter-phase-configuration?
+  (name opensmtpd-filter-phase-configuration-name ;; string chain-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter-phase-configuration" "name"
+                                 (list string?)))))
+  (phase opensmtpd-filter-phase-configuration-phase ;; string
+              (default #f)
+              (sanitize (lambda (var)
+                          ;;(my/sanitize var "opensmtpd-filter-phase-configuration" "phase"
+                          ;;             (list (sanitize-configuration
+                          ;;                    (proc (lambda (value)
+                          ;;                            (and (string? var)
+                          ;;                                 (string-in-list? var (list "connect"
+                          ;;                                                            "helo"
+                          ;;                                                            "mail-from"
+                          ;;                                                            "rcpt-to"
+                          ;;                                                            "data"
+                          ;;                                                            "commit")))))
+                          ;;                    (error-message (list
+                          ;;                                    "<opensmtpd-filter-phase-configuration> fieldname: 'phase' is of type \n"
+                          ;;                                    "string.  The string can be either 'connect',"
+                          ;;                                    " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n ")))))
+                          (if (and (string? var)
+                                   (string-in-list? var (list "connect"
+                                                          "helo"
+                                                          "mail-from"
+                                                          "rcpt-to"
+                                                          "data"
+                                                          "commit")))
+                              var
+                              (begin
+                                (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'phase' is of type \n"
+                                                        "string.  The string can be either 'connect',"
+                                                        " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n "
+                                                        ))
+                                (throw 'bad! var)))
+                          )))
+
+  (options opensmtpd-filter-phase-configuration-options
+              (default #f)
+              (sanitize (lambda (var)
+                          ;; returns #t if list is a unique list of <opensmtpd-option-configuration>
+                          (define (list-of-opensmtpd-option-configuration? list)
+                            (and (list-of-type? list opensmtpd-option-configuration?)
+                                 (not (contains-duplicate? list))))
+
+                          (define (list-has-duplicates-or-non-opensmtpd-option-configuration list)
+                            (not (list-of-opensmtpd-option-configuration? list)))
+
+                          ;; input <opensmtpd-option-configuration>
+                          ;; return #t if <opensmtpd-option-configuration> fieldname 'option'
+                          ;; that needs a corresponding table has one.  Otherwise #f
+                          (define (opensmtpd-option-configuration-has-table? record)
+                            (define decision (opensmtpd-option-configuration-option record))
+                            (and (string? decision)
+                                 ;; if option needs a table, check for a table
+                                 (if (string-in-list? decision (list "src"
+                                                                     "helo"
+                                                                     "mail-from"
+                                                                     "rcpt-to"))
+                                     (opensmtpd-table-configuration? (opensmtpd-option-configuration-data record))
+                                     #t)))
+
+                          (define (list-of-opensmtpd-option-configuration-has-table? list)
+                            (list-of-type? list opensmtpd-option-configuration-has-table?))
+
+                          (define (some-opensmtpd-option-configuration-in-list-lack-table? list)
+                            (not (list-of-opensmtpd-option-configuration-has-table? list)))
+
+                          ;;each element in list is of type <opensmtpd-option-configuration>
+                          (cond [(list-has-duplicates-or-non-opensmtpd-option-configuration var)
+                                 (begin
+                                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'options' is a list of unique \n"
+                                                           "<opensmtpd-option-configuration> records.\n"))
+                                   (throw 'bad! var))]
+                                ;; if fieldname 'option' is of string 'src', 'helo', 'mail-from', 'rcpt-to', then there should be a table
+                                [(some-opensmtpd-option-configuration-in-list-lack-table? var)
+                                 (begin
+                                   (display (string-append "<opensmtpd-option-configuration>'s fieldname 'option' values of \n"
+                                                           "'src', 'helo', 'mail-from', or 'rcpt-to' need a corresponding 'table' \n"
+                                                           " of type <opensmtpd-table-configuration>. eg: \n"
+                                                           "(opensmtpd-option-configuration \n"
+                                                           "   (option \"src\")\n"
+                                                           "   (table (opensmtpd-table-configuration \n"
+                                                           "              (name \"src-table\")\n"
+                                                           "              (data (list \"hello\" \"cat\")))))\n"))
+                                   ;; TODO it would be nice if the var this error message throws in the bad
+                                   ;; <opensmtpd-option-configuration>, instead of the list of records.
+                                   (throw 'bad! var))]
+                                [else var]))))
+  (decision opensmtpd-filter-phase-configuration-decision
+            (default #f)
+            (sanitize (lambda (var)
+                        (if (and (string? var)
+                                 (string-in-list? var (list "bypass" "disconnect"
+                                                            "reject" "rewrite" "junk")))
+                            var
+                            (begin
+                              (display (string-append "<opensmtpd-filter-decision> fieldname: 'decision' is of type \n"
+                                                      "string.  The string can be either 'bypass',"
+                                                      " 'disconnect', 'reject', 'rewrite', or 'junk'.\n"))
+                              (throw 'bad! var))))))
+  (message opensmtpd-filter-phase-configuration-message
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase-configuration" "message"
+                                    (list false? string?)))))
+  (value opensmtpd-filter-phase-configuration-value
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase-configuration" "value"
+                                    (list false? number?))))))
+
+(define-record-type* <opensmtpd-filter-configuration>
+  opensmtpd-filter-configuration make-opensmtpd-filter-configuration
+  opensmtpd-filter-configuration?
+  (name opensmtpd-filter-configuration-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "name"
+                                 (list string?)))))
+  (exec opensmtpd-filter-exec
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "exec"
+                                 (list boolean?)))))
+  (proc opensmtpd-filter-configuration-proc ; a string like "rspamd" or the command to start it like "/path/to/rspamd --option=arg --2nd-option=arg2"
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-filter" "proc"
+                                      (list string?))))))
+
+;; There is another type of filter that opensmtpd supports, which is a filter chain.
+;; A filter chain is a list of <opensmtpd-filter-phase-configuration> and <opensmtpd-filter-configuration>.
+;; This lets you apply several filters under one filter name.  I could have defined
+;; a record type for it, but the record would only have had two fields: name and list-of-filters.
+;; Why write that as a record?  That's too simple.
+;; returns #t if list is a unique list of <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>
+;; returns # otherwise
+(define (opensmtpd-filter-chain? %filters)
+  (and (list-of-unique-filter-or-filter-phase? %filters)
+       (< 1 (length %filters))))
+
+(define-record-type* <opensmtpd-listen-on-configuration>
+  opensmtpd-listen-on-configuration make-opensmtpd-listen-on-configuration
+  opensmtpd-listen-on-configuration?
+  ;; interface may be an IP address, interface group, or domain name
+  (interface opensmtpd-listen-on-configuration-interface
+             (default "lo"))
+  (family opensmtpd-listen-on-configuration-family
+          (default #f)
+          (sanitize (lambda (var)
+                      (cond
+                       [(eq? #f var) ;; var == #f
+                        var]
+                       [(and (string? var)
+                             (string-in-list? var (list "inet4" "inet6")))
+                        var]
+                       [else
+                        (begin
+                          (display "<opensmtpd-listen-on-configuration> fieldname 'family' must be string \"inet4\" or \"inet6\".\n")
+                          (throw 'bad! var))]))))
+  (auth opensmtpd-listen-on-configuration-auth
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-listen-on-configuration" "auth"
+                                 (list boolean? table-whose-data-are-assoc-list?)))))
+  (auth-optional opensmtpd-listen-on-configuration-auth-optional
+                 (default #f)
+                 (sanitize (lambda (var)
+                             (my/sanitize var "opensmtpd-listen-on-configuration" "auth-optional"
+                                          (list boolean?
+                                                table-whose-data-are-assoc-list?)))))
+  ;; TODO add a ca entry?
+  ;; string FIXME/TODO sanitize this to support a gexp.  That way way the
+  ;; includes directive can include my hacky scheme code that I use for opensmtpd-dkimsign.
+  (filters opensmtpd-listen-on-configuration-filters
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-filters var))))
+  (hostname opensmtpd-listen-on-configuration-hostname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-listen-on-configuration" "hostname"
+                                     (list false? string?)))))
+  (hostnames opensmtpd-listen-on-configuration-hostnames
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-listen-on-configuration" "hostnames"
+                                      (list false? table-whose-data-are-assoc-list?)))))
+  (mask-src opensmtpd-listen-on-configuration-mask-src
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-listen-on-configuration" "mask-src"
+                                     (list boolean?)))))
+  (disable-dsn opensmtpd-listen-on-configuration-disable-dsn
+          (default #f))
+  (pki opensmtpd-listen-on-configuration-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "pki"
+                                (list false? opensmtpd-pki-configuration?)))))
+  (port opensmtpd-listen-on-configuration-port
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-listen-on-configuration" "port"
+                                 (list false? integer?)))))
+  (proxy-v2 opensmtpd-listen-on-configuration-proxy-k2
+            (default #f))
+  (received-auth opensmtpd-listen-on-configuration-received-auth
+                 (default #f))
+  ;; TODO add in a senders option!
+  ;; string or <opensmtpd-senders> record
+  ;; (senders opensmtpd-listen-on-configuration-senders
+  ;;          (sanitize (lambda (var)
+  ;;                      (my/sanitize var "opensmtpd-listen-on-configuration" "port" (list false? integer?))))
+  ;;          (default #f))
+  (secure-connection opensmtpd-listen-on-configuration-secure-connection
+                     (default #f)
+                     (sanitize (lambda (var)
+                                 (cond [(boolean? var)
+                                        var]
+                                       [(and (string? var)
+                                             (string-in-list? var
+                                                              (list "smtps" "tls"
+                                                                    "tls-require"
+                                                                    "tls-require-verify")))
+                                        var]
+                                       [else
+                                        (begin
+                                          (display (string-append "<opensmtd-listen-on> fieldname 'secure-connection' can be \n"
+                                                                  "one of the following strings: \n'smtps', 'tls', 'tls-require', \n"
+                                                                  "or 'tls-require-verify'.\n"))
+                                          (throw 'bad! var))]))))
+  (tag opensmtpd-listen-on-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+(define-record-type* <opensmtpd-listen-on-socket-configuration-configuration>
+  opensmtpd-listen-on-socket-configuration-configuration make-opensmtpd-listen-on-socket-configuration-configuration
+  opensmtpd-listen-on-socket-configuration-configuration?
+  ;; false or <opensmtpd-filter-configuration> or list of <opensmtpd-filter-configuration>
+  (filters opensmtpd-listen-on-socket-configuration-configuration-filters
+           (sanitize (lambda (var)
+                       (sanitize-filters var)))
+          (default #f))
+  (mask-src opensmtpd-listen-on-socket-configuration-configuration-mask-src
+            (default #f))
+  (tag opensmtpd-listen-on-socket-configuration-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-listen-on-configuration" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+
+(define-record-type* <opensmtpd-match-configuration>
+  opensmtpd-match-configuration make-opensmtpd-match-configuration
+  opensmtpd-match-configuration?
+  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
+  ;;is #t, then the match record will be a reject match record.
+  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action 'reject))
+  ;; To do this, I will also have to  'reject' mutually exclusive. AND an match with 'reject' can have no action defined.
+  (action opensmtpd-match-configuration-action
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (or (opensmtpd-action-relay-configuration? var)
+                              (opensmtpd-action-local-delivery-configuration? var)
+                              (eq? (quote reject) var))
+                          var
+                          (begin
+                            (display
+                             (string-append "<opensmtpd-match-configuration> fieldname 'action' is of type <opensmtpd-action-relay-configuration>, \n"
+                                            "<opensmtpd-action-local-delivery-configuration>, or (quote reject).\n"
+                                            "If its var is (quote reject), then the match rejects the incoming message\n"
+                                            "during the SMTP dialogue.\n"))
+                            (throw 'bad! var))))))
+  (options opensmtpd-match-configuration-options
+           (default #f)
+           (sanitize (lambda (var)
+                       (cond ((not var)
+                              #f)
+                             ((not (list-of-unique-opensmtpd-option-configuration? var))
+                              (throw-error var '("<opensmtpd-match-configuration> fieldname 'options' is a list of unique \n"
+                                                 "<opensmtpd-option-configuration> records. \n")))
+                           (else (sanitize-list-of-options-for-match-configuration var)))))))
+
+(define-record-type* <opensmtpd-smtp-configuration>
+  opensmtpd-smtp-configuration make-opensmtpd-smtp-configuration
+  opensmtpd-smtp-configuration?
+  (ciphers opensmtpd-smtp-configuration-ciphers
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-smtp-configuration" "ciphers"
+                                    (list false? string?)))))
+  (limit-max-mails opensmtpd-smtp-configuration-limit-max-mails
+                   (default #f)
+                   (sanitize (lambda (var)
+                               (my/sanitize var "opensmtpd-smtp-configuration" "limit-max-mails"
+                                            (list false? integer?)))))
+  (limit-max-rcpt opensmtpd-smtp-configuration-limit-max-rcpt
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp-configuration" "limit-max-rcpt"
+                                           (list false? integer?)))))
+  (max-message-size opensmtpd-smtp-configuration-max-message-size
+                    (default #f)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-smtp-configuration" "max-message-size"
+                                             (list false? integer? string?)))))
+  ;; FIXME/TODO the sanitize function of sub-addr-delim should accept a string of length one not string?
+  (sub-addr-delim opensmtpd-smtp-configuration-sub-addr-delim
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp-configuration" "sub-addr-delim"
+                                           (list false? integer? string?))))))
+
+(define-record-type* <opensmtpd-srs-configuration>
+  opensmtpd-srs-configuration make-opensmtpd-srs-configuration
+  opensmtpd-srs-configuration?
+  ;; TODO should this be a file?
+  (key opensmtpd-srs-configuration-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-srs-configuration" "key"
+                                (list false? boolean? string?)))))
+  ;; TODO should this also be a file?
+  (backup-key opensmtpd-srs-configuration-backup-key
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-srs-configuration" "backup-key"
+                                       (list false? integer?)))))
+  (ttl-delay opensmtpd-srs-configuration-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-srs-configuration" "ttl-delay"
+                                      (list false? string?))))))
+
+(define-record-type* <opensmtpd-queue-configuration>
+  opensmtpd-queue-configuration make-opensmtpd-queue-configuration
+  opensmtpd-queue-configuration?
+  (compression opensmtpd-queue-configuration-compression
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-queue-configuration" "compression"
+                                        (list boolean?)))))
+  (encryption opensmtpd-queue-configuration-encryption
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-queue-configuration" "encryption"
+                                       (list boolean? file-exists? string?)))))
+  (ttl-delay opensmtpd-queue-configuration-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-queue-configuration" "ttl-delay"
+                                      (list false? string?))))))
+
 (define-record-type* <opensmtpd-configuration>
   opensmtpd-configuration make-opensmtpd-configuration
   opensmtpd-configuration?
-  (package     opensmtpd-configuration-package
-               (default opensmtpd))
+  (package opensmtpd-configuration-package
+           (default opensmtpd))
   (config-file opensmtpd-configuration-config-file
-               (default %default-opensmtpd-config-file)))
+               (default #f))
+  ;; FIXME/TODO should I include a admd authservid entry?
+
+  ;; TODO sanitize this properly with perhaps a <sanitize-configuration>.
+  (bounce opensmtpd-configuration-bounce
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-configuration" "bounce"
+                                   (list false? list?)))))
+  (cas opensmtpd-configuration-cas
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "cas"
+                                (list false? list-of-opensmtpd-ca-configuration?)))))
+  ;; list of many records of type opensmtpd-listen-on-configuration
+  (listen-ons opensmtpd-configuration-listen-ons
+              (default (list (opensmtpd-listen-on-configuration)))
+              (sanitize (lambda (var)
+                          (if (list-of-opensmtpd-listen-on-configuration? var)
+                              var
+                              (begin
+                                (display "<opensmtpd-configuration> fieldname 'listen-ons' expects a list of records ")
+                                (display "of one or more unique <opensmtpd-listen-on-configuration> records.\n")
+                                (throw 'bad! var))))))
+  ;; accepts type <opensmtpd-listen-on-socket-configuration-configuration>
+  (listen-on-socket opensmtpd-configuration-listen-on-socket
+                    (default (opensmtpd-listen-on-socket-configuration-configuration)))
+  (includes opensmtpd-configuration-includes ;; list of strings of absolute path names
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-configuration" "includes"
+                                     (list false? list-of-strings?)))))
+  (matches opensmtpd-configuration-matches
+           (default (list (opensmtpd-match-configuration
+                           (action (opensmtpd-action-local-delivery-configuration
+                                    (name "local")
+                                    (method "mbox")))
+                           (options (list
+                                     (opensmtpd-option-configuration
+                                      (option "for local")))))
+                          (opensmtpd-match-configuration
+                           (action (opensmtpd-action-relay-configuration
+                                    (name "outbound")))
+                           (options (list
+                                     (opensmtpd-option-configuration
+                                      (option "from local"))
+                                     (opensmtpd-option-configuration
+                                      (option "for any")))))))
+           ;; TODO perhaps I should sanitize this function like I sanitized the 'filters'.
+           ;; I definitely should sanitize this function a bit more.  For example, you could have two different
+           ;; actions, one for local delivery and one for remote, with the same name.  I should make sure that
+           ;; I have no two different actions with the same name.
+           (sanitize (lambda (var)
+                       ;; Should we do more sanitizing here?  eg: "from socket" should NOT have a table or value
+                       var
+                       (my/sanitize var "opensmtpd-configuration" "matches"
+                                    (list list-of-unique-opensmtpd-match-configuration?)))))
+  ;; list of many records of type mda-wrapper
+  ;; TODO/FIXME support using gexps here
+  ;; eg (list "name" gexp)
+  (mda-wrappers opensmtpd-configuration-mda-wrappers
+                (default #f)
+                (sanitize (lambda (var)
+                            (my/sanitize var
+                                         "opensmtpd-configuration"
+                                         "mda-wrappers"
+                                         (list false? string?)))))
+  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
+                    (default 100)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-configuration" "mta-max-deferred"
+                                             (list number?)))))
+
+  ;; TODO should I add a fieldname proc _proc-name_ _command_ as found in the man 5 smtpd.conf ?
+
+  (queue opensmtpd-configuration-queue
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-configuration" "queue"
+                                  (list false? opensmtpd-queue-configuration?)))))
+  (smtp opensmtpd-configuration-smtp
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-configuration" "smtp"
+                                 (list false? opensmtpd-smtp-configuration?)))))
+  (srs opensmtpd-configuration-srs
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "srs"
+                                (list false? opensmtpd-srs-configuration?))))))
+
+;; This is a non-exported record for passing around sanitize procedures.
+;; As of 5/2/2022 I am not using it.  I should probably just delete it.
+(define-record-type* <sanitize-configuration>
+  sanitize-configuration make-sanitize-configuration
+  sanitize-configuration?
+  (proc sanitize-configuration-proc
+          (default #f)
+          ;;(sanitize (lambda (var) (procedure? var)))
+          )
+  (args sanitize-configuration-args
+       (default #f)
+       ;;(sanitize (lambda (var) (lambda (var) (list? var))))
+       )
+  (error-message sanitize-configuration-error-message
+         (default #f)
+         ;;(sanitize (lambda (var) (list? var)))
+         )
+  (error-if-proc-fails sanitize-configuration-error-if-proc-fails
+                       (default #f)))
+
+;; this help procedure is used 3 or 4 times by sanitize-list-of-options-for-match-configuration
+(define (throw-error-duplicate-option option error-arg)
+  (throw-error error-arg
+               (list "<opensmtpd-match-configuration>'s fieldname 'options' has two\n"
+                     (string-append "<opensmtpd-option-configuration> records with fieldname 'option' with value '" option "'. \n")
+                     (string-append "You can only have one option with value '" option "' in the options list.\n"))))
+
+;; this procedure sanitizes the fieldname opensmtpd-match-configuration-options
+(define* (sanitize-list-of-options-for-match-configuration %options)
+  (let loop ([%traversing-options %options]
+             [%sanitized-options '()])
+    (if (null? %traversing-options)
+           (remove false?
+                   (list
+                    (assoc-ref %sanitized-options "for")
+                    (assoc-ref %sanitized-options "from")
+                    (assoc-ref %sanitized-options "auth")
+                    (assoc-ref %sanitized-options "helo")
+                    (assoc-ref %sanitized-options "mail-from")
+                    (assoc-ref %sanitized-options "rcpt-to")
+                    (assoc-ref %sanitized-options "tag")
+                    (assoc-ref %sanitized-options "tls")))
+          (let* ((option-record (car %traversing-options))
+                 (option-string (opensmtpd-option-configuration-option option-record)))
+            (cond [(string=? "auth" option-string)
+                   (if (assoc-ref %sanitized-options "auth")
+                       (throw-error-duplicate-option "auth" %traversing-options)
+                       (loop (cdr %traversing-options) (alist-cons "auth" option-record %sanitized-options)))]
+                  [(string=? "helo" option-string)
+                   (cond [(assoc-ref %sanitized-options "helo")
+                          (throw-error-duplicate-option "helo" %traversing-options)]
+                         [(not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'helo' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "helo" option-record %sanitized-options))])]
+                  [(string=? "mail-from" option-string)
+                   (cond ((assoc-ref %sanitized-options "mail-from")
+                          (throw-error-duplicate-option "mail-from" %traversing-options))
+                         ((not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'mail-from' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "mail-from" option-record %sanitized-options))))]
+                  [(string=? "rcpt-to" option-string)
+                   (cond [(assoc-ref %sanitized-options "rcpt-to")
+                          (throw-error-duplicate-option "rcpt-to" %traversing-options)]
+                         [(not (opensmtpd-option-configuration-data option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'rcpt-to' \n"
+                                             "must have a 'data' of type string or <opensmtpd-table-configuration>.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "rcpt-to" option-record %sanitized-options))])]
+                  [(string=? "tag" option-string)
+                   (cond ((assoc-ref %sanitized-options "tag")
+                          (throw-error-duplicate-option "tag" %traversing-options))
+                         ((not (string? (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'tag' \n"
+                                             "must have a 'data' of type string.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "tag" option-record %sanitized-options))))]
+                  [(string=? "tls" option-string)
+                   (cond [(assoc-ref %sanitized-options "tls")
+                          (throw-error-duplicate-option "tls" %traversing-options)]
+                         [(or (opensmtpd-option-configuration-data option-record)
+                              (opensmtpd-option-configuration-regex option-record))
+                          (throw-error option-record
+                                       (list "<opensmtpd-option-configuration> with fieldname 'option' with value 'tls' \n"
+                                             "cannot have a string or table 'data'.\n"))]
+                         [else (loop (cdr %traversing-options) (alist-cons "tls" option-record %sanitized-options))])]
+                  [(string=? "for" (substring option-string 0 3))
+                   (cond ((assoc-ref %sanitized-options "for")
+                          (throw-error %options
+                                       `("<opensmtpd-match-configuration>'s fieldname 'options' can only have one 'for' option. \n"
+                                         "But '" ,option-string "' and '"
+                                         ,(opensmtpd-option-configuration-option (assoc-ref %sanitized-options "for")) "' are present.\n")))
+                         ((and (string-in-list? option-string (list "for any" "for local")) ; for any cannot have a data field.
+                               (or (opensmtpd-option-configuration-data option-record)
+                                   (opensmtpd-option-configuration-regex option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for any' \n"
+                                             "or 'for local', then its 'data' and 'regex' field must be #f. \n")))
+                         ((and (string-in-list? option-string (list "for domain" "for rcpt-to")) ; for domain must have a data field.
+                               (not (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for domain' \n"
+                                             "or 'for rcpt-to', then its 'data' field must be a string or an \n"
+                                             "<opensmtpd-table-configuration> record.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "for" option-record %sanitized-options))))]
+                  [(string=? "from" (substring option-string 0 4))
+                   (cond ((assoc-ref %sanitized-options "from")
+                          (throw-error %options
+                                       `("<opensmtpd-match-configuration>'s fieldname 'options' can only have one 'from' option. \n"
+                                         "But '" ,option-string "' and '"
+                                         ,(opensmtpd-option-configuration-option (assoc-ref %sanitized-options "from")) "' are present.\n")))
+                         ((and (string-in-list? option-string (list "from any" "from local" "from socket")) ; for any cannot have a data field.
+                               (or (opensmtpd-option-configuration-data option-record)
+                                   (opensmtpd-option-configuration-regex option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from any', \n"
+                                             " 'from local', or 'from socket', then its 'data' and 'regex' field must be #f. \n")))
+                         ((and (string-in-list? option-string (list "from mail-from" "from src")) ; for domain must have a data field.
+                               (not (opensmtpd-option-configuration-data option-record)))
+                          (throw-error option-record
+                                       (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from mail-from' \n"
+                                             "or 'from src', then its 'data' field must be a string or an \n"
+                                             "<opensmtpd-table-configuration> record.\n")))
+                         (else (loop (cdr %traversing-options) (alist-cons "from" option-record %sanitized-options))))])))))
+
+;; some procedures for <opensmtpd-listen-on-configuration> and
+;; <opensmtpd-listen-on-socket-configuration-configuration>.
+(define (sanitize-filters %list)
+  ;; the order of the first two tests in this cond is important.
+  ;; (false?) has to be 1st and (list-has-duplicates-or-non-filters?) has to be second.
+  ;; You may optionally re-order the other alternates in the cond.
+  (cond [(false? %list)
+         #f]
+        [(list-has-duplicates-or-non-filters? %list)
+         (begin
+           (display (string-append "<opensmtpd-listen-on-configuration> fieldname: 'filters' is a list, in which each unique element \n"
+                                   "is of type <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>.\n"))
+           (throw 'bad! %list))]
+        [else
+         (let loop ([%traversing-list %list]
+                    [%original-list %list])
+           (if (null? %traversing-list)
+               %original-list
+               (cond
+                [(opensmtpd-filter-configuration? (car %traversing-list))
+                 (loop (cdr %traversing-list) %original-list)]
+                [(filter-phase-has-message-and-value? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> cannot have defined fieldnames 'value' \n"
+                                           "and 'message'.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-decision-lacks-proper-message? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'decision' options \n"
+                                           "\"disconnect\" and \"reject\" require fieldname 'message' to have a string.\n"
+                                           "The 'message' string must be RFC commpliant, which means that the string \n"
+                                           "must begin with a 4xx or 5xx status code.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-lacks-proper-value? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname: 'decision' option \n"
+                                           "\"rewrite\" requires fieldname 'value' to have a number.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-has-incorrect-junk-or-bypass? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname 'decision' option \n"
+                                           "\"junk\" or 'bypass' cannot have a defined fieldnames 'message' or 'value'.\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [(filter-phase-junks-after-commit? (car %traversing-list))
+                 (begin
+                   (display (string-append "<opensmtpd-filter-phase-configuration> fieldname 'decision' option \n"
+                                           "\"junk\" cannot junk an email during 'phase' \"commit\".\n"))
+                   (throw 'bad! (car %traversing-list)))]
+                [else (loop (cdr %traversing-list) %original-list)])))]))
+
+(define (list-has-duplicates-or-non-filters? list)
+  (not (list-of-unique-filter-or-filter-phase? list)))
+
+(define (filter-phase-has-message-and-value? record)
+  (and (opensmtpd-filter-phase-configuration-message record)
+       (opensmtpd-filter-phase-configuration-value record)))
+
+;; return #t if phase needs a message. Or if the message did not start with a 4xx or 5xx status code.
+;; otherwise #f
+(define (filter-phase-decision-lacks-proper-message? record)
+  (define decision (opensmtpd-filter-phase-configuration-decision record))
+  (if (string-in-list? decision (list "disconnect" "reject"))
+      ;; this message needs to be RFC compliant, meaning
+      ;; that it need to start with 4xx or 5xx status code
+      (cond [(eq? #f (opensmtpd-filter-phase-configuration-message record))
+             #t]
+            [(string? (opensmtpd-filter-phase-configuration-message record))
+             (let ((number (string->number
+                            (substring
+                             (opensmtpd-filter-phase-configuration-message record) 0 3))))
+               (if (and (number? number)
+                        (and (< number 600) (> number 399)))
+                   #f
+                   #t))])
+      #f))
+
+;; 'decision' "rewrite" requires 'value' to be a number.
+(define (filter-phase-lacks-proper-value? record)
+  (define decision (opensmtpd-filter-phase-configuration-decision record))
+  (if (string=? "rewrite" decision)
+      (if (and (number? (opensmtpd-filter-phase-configuration-value record))
+               (eq? #f (opensmtpd-filter-phase-configuration-message record)))
+          #f
+          #t)
+      #f))
+
+;; 'decision' "junk" or "bypass" cannot have a message or a value.
+(define (filter-phase-has-incorrect-junk-or-bypass? record)
+  (and
+   (string-in-list?
+    (opensmtpd-filter-phase-configuration-decision record)
+    (list "junk" "bypass"))
+   (or
+    (opensmtpd-filter-phase-configuration-value record)
+    (opensmtpd-filter-phase-configuration-message record))))
+
+(define (filter-phase-junks-after-commit? record)
+  (and (string=? (opensmtpd-filter-phase-configuration-decision record) "junk")
+       (string=? (opensmtpd-filter-phase-configuration-phase record) "commit")))
+
+;; returns #t if list is a unique list of <opensmtpd-filter-configuration> or <opensmtpd-filter-phase-configuration>
+;; returns # otherwise
+(define (list-of-unique-filter-or-filter-phase? %filters)
+  (and (list? %filters)
+       (not (null? %filters))
+       ;; this list is made up of only <opensmtpd-filter-phase-configuration> or <opensmtpd-filter-configuration>
+       (primitive-eval
+        (cons 'and (map (lambda (filter)
+                          (or (opensmtpd-filter-configuration? filter)
+                              (opensmtpd-filter-phase-configuration? filter)))
+                        %filters)))
+       (not (contains-duplicate? %filters))))
+
+(define (throw-error var %strings)
+  (display (apply string-append %strings))
+  (throw 'bad! var))
+
+;; this is used for sanitizing <opensmtpd-filter-phase-configuration> fieldname 'options'
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+      ;; check if (car list) is in (cdr list)
+       (primitive-eval (cons 'or
+                                (map (lambda (var) (equal? var (car list)))
+                                     (cdr list))))
+       ;; check if (cdr list) contains duplicate
+       (contains-duplicate? (cdr list)))))
+
+;; given a list and procedure, this tests that each element of list is of type
+;; ie: (list-of-type? list string?) tests each list is of type string.
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ([list list])
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+
+(define (list-of-strings? list)
+  (list-of-type? list string?))
+
+(define (list-of-unique-opensmtpd-option-configuration? list)
+  (and (list-of-type?
+        list opensmtpd-option-configuration?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-opensmtpd-ca-configuration? list)
+  (list-of-type? list opensmtpd-ca-configuration?))
+
+(define (list-of-opensmtpd-pki-configuration? list)
+  (list-of-type? list opensmtpd-pki-configuration?))
+
+(define (list-of-opensmtpd-listen-on-configuration? list)
+  (and (list-of-type? list opensmtpd-listen-on-configuration?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-unique-opensmtpd-match-configuration? list)
+  (and (list-of-type? list opensmtpd-match-configuration?)
+       (not (contains-duplicate? list))))
+
+(define* (list-of-strings->string list
+                                  #:key
+                                  (string-delimiter ", ")
+                                  (postpend "")
+                                  (append "")
+                                  (drop-right-number 2))
+  (string-drop-right
+   (string-append (let loop ([list list])
+                    (if (null? list)
+                        ""
+                        (string-append append (car list) postpend
+                                       string-delimiter
+                                       (loop (cdr list)))))
+                  append)
+   drop-right-number))
+
+;; at the moment I cannot define this by using list-of-type?
+;; the first (not (null? assoc-list)) prevents that.
+(define (assoc-list? assoc-list)
+  (list-of-type? assoc-list (lambda (pair)
+                              (if (and (pair? pair)
+                                       (string? (car pair))
+                                       (string? (cdr pair)))
+                                  #t
+                                  #f))))
+
+(define* (variable->string var #:key (append "") (postpend " "))
+  (let ([var (if (number? var)
+                 (number->string var)
+                 var)])
+    (if var
+        (string-append append var postpend)
+        "")))
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is an assoc-list, then it returns
+;; #t, #f if otherwise.
+;; TODO should I remove these two functions?  And instead use the (opensmtpd-table-configuration-type) procedure?
+(define (table-whose-data-are-assoc-list? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (assoc-list? (opensmtpd-table-configuration-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table-configuration> whose fieldname 'values' is a list of strings, then it returns
+;; #t, #f if otherwise.
+(define (table-whose-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table-configuration? table))
+      #f
+      (list-of-strings? (opensmtpd-table-configuration-data table))))
+
+;; these next few functions help me to turn <table>s
+;; into strings suitable to fit into "opensmtpd.conf".
+(define (assoc-list->string assoc-list)
+  (string-drop-right
+   (let loop ([assoc-list assoc-list])
+     (if (null? assoc-list)
+         ""
+         ;; pair is (cons "hello" "world") -> ("hello" . "world")
+         (let ([pair (car assoc-list)])
+           (string-append
+            "\"" (car pair)  "\""
+            " = "
+            "\"" (cdr pair) "\""
+            ", "
+            (loop (cdr assoc-list))))))
+   2))
+
+;; can be of type: (quote list-of-strings) or (quote assoc-list)
+(define (opensmtpd-table-configuration->string table)
+  (string-append "table " (opensmtpd-table-configuration-name table) " "
+                 (let ([type (opensmtpd-table-configuration-type table)])
+                   (cond [(eq? type (quote list-of-strings))
+                          (string-append "{ " (list-of-strings->string (opensmtpd-table-configuration-data table)
+                                                                       #:append "\""
+                                                                       #:drop-right-number 3
+                                                                       #:postpend "\"") " }")]
+                         [(eq? type (quote assoc-list))
+                          (string-append "{ " (assoc-list->string (opensmtpd-table-configuration-data table)) " }")]
+                         [(eq? type (quote db))
+                          (string-append "db:" (opensmtpd-table-configuration-data table))]
+                         [(eq? type (quote file))
+                          (string-append "file:" (opensmtpd-table-configuration-data table))]
+                         [else (throw 'youMessedUp table)]))
+                 " \n"))
+
+;;  The following functions convert various records into strings.
+
+(define (opensmtpd-listen-on-configuration->string record)
+  (string-append "listen on "
+                 (opensmtpd-listen-on-configuration-interface record) " "
+                 (let* ([hostname (opensmtpd-listen-on-configuration-hostname record)]
+                        [hostnames (if (opensmtpd-listen-on-configuration-hostnames record)
+                                       (opensmtpd-table-configuration-name (opensmtpd-listen-on-configuration-hostnames record))
+                                       #f)]
+                        [filters (opensmtpd-listen-on-configuration-filters record)]
+                        [filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter-configuration? (car filters))
+                                                 (opensmtpd-filter-configuration-name (car filters))
+                                                 (opensmtpd-filter-phase-configuration-name (car filters))))
+                                         #f)]
+                        [mask-src (opensmtpd-listen-on-configuration-mask-src record)]
+                        [tag (opensmtpd-listen-on-configuration-tag record)]
+                        [secure-connection (opensmtpd-listen-on-configuration-secure-connection record)]
+                        [port (opensmtpd-listen-on-configuration-port record)]
+                        [pki (opensmtpd-listen-on-configuration-pki record)]
+                        [auth (opensmtpd-listen-on-configuration-auth record)]
+                        [auth-optional (opensmtpd-listen-on-configuration-auth-optional record)])
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string hostname #:append "hostname ")
+                    (variable->string hostnames #:append "hostnames <" #:postpend "> ")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    (if secure-connection
+                        (cond [(string=? "smtps" secure-connection)
+                               "smtps "]
+                              [(string=? "tls" secure-connection)
+                               "tls "]
+                              [(string=? "tls-require" secure-connection)
+                               "tls-require "]
+                              [(string=? "tls-require-verify" secure-connection)
+                               "tls-require verify "])
+                        "")
+                    (variable->string port #:append "port " #:postpend " ")
+                    (if pki
+                        (variable->string (opensmtpd-pki-configuration-domain pki) #:append "pki ")
+                        "")
+                    (if auth
+                        (string-append "auth "
+                                       (if (opensmtpd-table-configuration? auth)
+                                           (string-append "<" (opensmtpd-table-configuration-name auth) "> ")
+                                           ""))
+                        "")
+                    (if auth-optional
+                        (string-append "auth-optional "
+                                       (if (opensmtpd-table-configuration? auth-optional)
+                                           (string-append "<" (opensmtpd-table-configuration-name auth-optional) "> ")
+                                           ""))
+                        "")
+                    "\n"))))
+
+(define (opensmtpd-listen-on-socket-configuration->string record)
+  (string-append "listen on socket "
+                 (let* ([filters (opensmtpd-listen-on-socket-configuration-configuration-filters record)]
+                        [filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter-configuration? (car filters))
+                                                 (opensmtpd-filter-configuration-name (car filters))
+                                                 (opensmtpd-filter-phase-configuration-name (car filters))))
+                                         #f)]
+                        [mask-src (opensmtpd-listen-on-socket-configuration-configuration-mask-src record)]
+                        [tag (opensmtpd-listen-on-socket-configuration-configuration-tag record)])
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    "\n"))))
+
+(define (opensmtpd-action-relay-configuration->string record)
+  (let ([backup (opensmtpd-action-relay-configuration-backup record)]
+        [backup-mx (opensmtpd-action-relay-configuration-backup-mx record)]
+        [helo (opensmtpd-action-relay-configuration-helo record)]
+        ;; helo-src can either be a string IP address or an <opensmtpd-table-configuration>
+        [helo-src (if (opensmtpd-action-relay-configuration-helo-src record)
+                      (if (string? (opensmtpd-action-relay-configuration-helo-src record))
+                          (opensmtpd-action-relay-configuration-helo-src record)
+                          (string-append "<\""
+                                         (opensmtpd-table-configuration-name
+                                          (opensmtpd-action-relay-configuration-src record))
+                                         "\">"))
+                      #f)]
+        [domain (if (opensmtpd-action-relay-configuration-domain record)
+                    (opensmtpd-table-configuration-name
+                     (opensmtpd-action-relay-configuration-domain record))
+                    #f)]
+        [host (opensmtpd-action-relay-configuration-host record)]
+        [name (opensmtpd-action-relay-configuration-name record)]
+        [pki (if (opensmtpd-action-relay-configuration-pki record)
+                 (opensmtpd-pki-configuration-domain (opensmtpd-action-relay-configuration-pki record))
+                 #f)]
+        [srs (opensmtpd-action-relay-configuration-srs record)]
+        [tls (opensmtpd-action-relay-configuration-tls record)]
+        [auth (if (opensmtpd-action-relay-configuration-auth record)
+                  (opensmtpd-table-configuration-name
+                   (opensmtpd-action-relay-configuration-auth record))
+                  #f)]
+        [mail-from (opensmtpd-action-relay-configuration-mail-from record)]
+        ;; src can either be a string IP address or an <opensmtpd-table-configuration>
+        [src (if (opensmtpd-action-relay-configuration-src record)
+                 (if (string? (opensmtpd-action-relay-configuration-src record))
+                     (opensmtpd-action-relay-configuration-src record)
+                     (string-append "<\""
+                                    (opensmtpd-table-configuration-name
+                                     (opensmtpd-action-relay-configuration-src record))
+                                    "\">"))
+                 #f)]
+        )
+    (string-append
+     "\""
+     name
+     "\" " "relay "
+     ;;FIXME should I always quote the host fieldname? do I need to quote localhost via "localhost" ?
+     (variable->string host #:append "host \"" #:postpend "\" ")
+     (variable->string backup)
+     (variable->string backup-mx #:append "backup mx ")
+     (variable->string helo #:append "helo ")
+     (variable->string helo-src #:append "helo-src ")
+     (variable->string domain #:append "domain <\"" #:postpend "\"> ")
+     (variable->string host #:append "host ")
+     (variable->string pki #:append "pki ")
+     (variable->string srs)
+     (variable->string tls #:append "tls ")
+     (variable->string auth #:append "auth <" #:postpend "> ")
+     (variable->string mail-from #:append "mail-from ")
+     (variable->string src #:append "src ")
+     "\n")))
+
+(define (opensmtpd-lmtp-configuration->string record)
+  (string-append "lmtp "
+                 (opensmtpd-lmtp-configuration-destination record)
+                 (if (opensmtpd-lmtp-configuration-rcpt-to record)
+                     (begin
+                       " " (opensmtpd-lmtp-configuration-rcpt-to record))
+                     "")))
+
+(define (opensmtpd-mda-configuration->string record)
+  (string-append "mda "
+                 (opensmtpd-mda-configuration-command record) " "))
+
+(define (opensmtpd-maildir-configuration->string record)
+  (string-append "maildir "
+                 "\""
+                 (if (opensmtpd-maildir-configuration-pathname record)
+                     (opensmtpd-maildir-configuration-pathname record)
+                     "~/Maildir")
+                 "\""
+                 (if (opensmtpd-maildir-configuration-junk record)
+                     " junk "
+                     " ")))
+
+(define (opensmtpd-action-local-delivery-configuration->string record)
+  (let ([name (opensmtpd-action-local-delivery-configuration-name record)]
+        [method (opensmtpd-action-local-delivery-configuration-method record)]
+        [alias (if (opensmtpd-action-local-delivery-configuration-alias record)
+                   (opensmtpd-table-configuration-name
+                    (opensmtpd-action-local-delivery-configuration-alias record))
+                   #f)]
+        [ttl (opensmtpd-action-local-delivery-configuration-ttl record)]
+        [user (opensmtpd-action-local-delivery-configuration-user record)]
+        [userbase (if (opensmtpd-action-local-delivery-configuration-userbase record)
+                      (opensmtpd-table-configuration-name
+                       (opensmtpd-action-local-delivery-configuration-userbase record))
+                      #f)]
+        [virtual (if (opensmtpd-action-local-delivery-configuration-virtual record)
+                     (opensmtpd-table-configuration-name
+                      (opensmtpd-action-local-delivery-configuration-virtual record))
+                     #f)]
+        [wrapper (opensmtpd-action-local-delivery-configuration-wrapper record)])
+    (string-append
+     "\"" name "\" "
+     (cond [(string? method)
+            (string-append method " ")]
+           [(opensmtpd-mda-configuration? method)
+            (opensmtpd-mda-configuration->string method)]
+           [(opensmtpd-lmtp-configuration? method)
+            (opensmtpd-lmtp-configuration->string method)]
+           [(opensmtpd-maildir-configuration? method)
+            (opensmtpd-maildir-configuration->string method)])
+     ;; FIXME/TODO support specifying alias file:/path/to/alias-file  ?
+     ;; I do not think that is something that I can do...
+     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
+     (variable->string ttl #:append "ttl ")
+     (variable->string user #:append "user ")
+     (variable->string userbase #:append "userbase <\"" #:postpend "\"> ")
+     (variable->string virtual #:append "virtual <" #:postpend "> ")
+     (variable->string wrapper #:append "wrapper "))))
+
+;; this function turns both opensmtpd-action-local-delivery-configuration and
+;; opensmtpd-action-relay-configuration into strings.
+(define (opensmtpd-action->string record)
+  (string-append "action "
+                 (cond [(opensmtpd-action-local-delivery-configuration? record)
+                        (opensmtpd-action-local-delivery-configuration->string record)]
+                       [(opensmtpd-action-relay-configuration? record)
+                        (opensmtpd-action-relay-configuration->string record)])
+                 " \n"))
+
+;; this turns option records found in <opensmtpd-match-configuration> into strings.
+(define* (opensmtpd-option-configuration->string record
+                                                 #:key
+                                                 (space-after-! #f))
+  (let ([not (opensmtpd-option-configuration-not record)]
+        [option (opensmtpd-option-configuration-option record)]
+        [regex (opensmtpd-option-configuration-regex record)]
+        [data (opensmtpd-option-configuration-data record)])
+    (string-append
+     (if not
+         (if space-after-!
+             "! "
+             "!")
+         "")
+     option " "
+     (if regex
+         "regex "
+         "")
+     (if data
+         (if (opensmtpd-table-configuration? data)
+             (string-append "<" (opensmtpd-table-configuration-name data) "> ")
+             (string-append data " "))
+         ""))))
+
+(define (opensmtpd-match-configuration->string record)
+  (string-append "match "
+                 (let* ([action (opensmtpd-match-configuration-action record)]
+                        [name (cond [(opensmtpd-action-relay-configuration? action)
+                                     (opensmtpd-action-relay-configuration-name action)]
+                                    [(opensmtpd-action-local-delivery-configuration? action)
+                                     (opensmtpd-action-local-delivery-configuration-name action)]
+                                    [else 'reject])]
+                        [options (opensmtpd-match-configuration-options record)])
+                   (string-append
+                    (if options
+                        (apply string-append
+                               (map opensmtpd-option-configuration->string options))
+                        "")
+                    (if (string? name)
+                        (string-append "action " "\"" name "\" ")
+                        "reject ")
+                    "\n"))))
+
+(define (opensmtpd-ca-configuration->string record)
+  (string-append "ca " (opensmtpd-ca-configuration-name record) " "
+                 "cert \"" (opensmtpd-ca-configuration-file record) "\"\n"))
+
+(define (opensmtpd-pki-configuration->string record)
+  (let ([domain (opensmtpd-pki-configuration-domain record)]
+        [cert (opensmtpd-pki-configuration-cert record)]
+        [key (opensmtpd-pki-configuration-key record)]
+        [dhe (opensmtpd-pki-configuration-dhe record)])
+    (string-append "pki " domain " " "cert \"" cert "\" \n"
+                   "pki " domain " " "key \"" key "\" \n"
+                   (if dhe
+                       (string-append
+                        "pki " domain " " "dhe " dhe "\n")
+                       ""))))
+
+(define (generate-filter-chain-name list-of-filters)
+  (string-drop-right (apply string-append
+                            (flatten
+                             (map (lambda (filter)
+                                    (list
+                                     (if (opensmtpd-filter-configuration? filter)
+                                         (opensmtpd-filter-configuration-name filter)
+                                         (opensmtpd-filter-phase-configuration-name filter))
+                                     "-"))
+                                  list-of-filters)))
+                     1))
+
+;; this procedure takes in a list of <opensmtpd-filter-configuration> and <opensmtpd-filter-phase-configuration>,
+;; returns a string of the form:
+;; filter "uniquelyGeneratedName" chain chain { "filter-name", "filter-name2" [, ...]}
+(define (opensmtpd-filter-chain->string list-of-filters)
+  (string-append "filter \""
+                 (generate-filter-chain-name list-of-filters)
+                 "\" "
+                 "chain {"
+                 (string-drop-right
+                  (apply string-append
+                         (flatten
+                          (map (lambda (filter)
+                                 (list
+                                  "\""
+                                  (if (opensmtpd-filter-configuration? filter)
+                                      (opensmtpd-filter-configuration-name filter)
+                                      (opensmtpd-filter-phase-configuration-name filter))
+                                  "\", "))
+                               list-of-filters))
+                         ) 2)
+                 "}\n"))
+
+(define (opensmtpd-filter-phase-configuration->string record)
+  (let ([name (opensmtpd-filter-phase-configuration-name record)]
+        [phase (opensmtpd-filter-phase-configuration-phase record)]
+        [decision (opensmtpd-filter-phase-configuration-decision record)]
+        [options (opensmtpd-filter-phase-configuration-options record)]
+        [message (opensmtpd-filter-phase-configuration-message record)]
+        [value (opensmtpd-filter-phase-configuration-value record)])
+    (string-append "filter "
+                   "\"" name "\" "
+                   "phase " phase " "
+                   "match "
+                   (apply string-append ; turn the options into a string
+                          (flatten
+                           (map (lambda (option)
+                                  (opensmtpd-option-configuration->string option #:space-after-! #f))
+                                options)))
+                   " "
+                   decision " "
+                   (if (string-in-list? decision (list "reject" "disconnect"))
+                       (string-append "\"" message "\"")
+                       "")
+                   (if (string=? "rewrite" decision)
+                       (string-append "rewrite " (number->string value))
+                       "")
+                   "\n")))
+
+;; filters elements may be <opensmtpd-filter-configuration>, <opensmtpd-filter-phase-configuration>,
+;; and lists that look like (list (opensmtpd-filter-configuration...) (opensmtpd-filter-phase-configuration ...)
+;; ...)
+;; this function converts it to a string.
+;; Consider if a user passed in a valid <opensmtpd-configuration>, whose total valid filters
+;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
+;; look like this: (we will call this list "total filters"):
+;; (list (opensmtpd-filter
+;;         (name "rspamd")
+;;         (proc "rspamd"))
+;;       (list (opensmtpd-filter-phase-configuration ; this is a listen-on, with a filter-chain.
+;;               (name "dkimsign")
+;;               ...)
+;;               (opensmtpd-filter
+;;                 (name "rspamd")
+;;                 (proc "rspamd"))))
+;;
+;; did you notice that filter "rspamd" is listed twice?  How do you make sure that it is NOT
+;; printed twice in smtpd.conf?
+;; 1st flatten "total filters", then remove its duplicates.  Then print all of those filters.
+;; 2nd now we go through "total filters", and we only print the non-filter-chains.
+(define (opensmtpd-filters->string filters)
+  ;; first display the unique <opensmtpd-filter-configuration>s. and <opensmtpd-filter-phase-configuration>s.
+  ;; to do this: flatten filters, then remove duplicates.
+  (string-append
+   (apply string-append
+          (map (lambda (filter)
+                 (cond ((opensmtpd-filter-phase-configuration? filter)
+                        (opensmtpd-filter-phase-configuration->string filter))
+                       (else            ; you are a <opensmtpd-filter-configuration>
+                        (string-append "filter "
+                                       "\"" (opensmtpd-filter-configuration-name filter) "\" "
+                                       (if (opensmtpd-filter-exec filter)
+                                           "proc-exec "
+                                           "proc ")
+                                       "\"" (opensmtpd-filter-configuration-proc filter) "\""
+                                       "\n"))))
+               (delete-duplicates (flatten filters))))
+   ;; now we have to print the filter chains.
+   (apply string-append
+          (remove boolean?
+                  (map (lambda (filter)
+                         (cond ((list? filter)
+                                (opensmtpd-filter-chain->string filter))
+                               (else    ; you are a <opensmtpd-filter-configuration>
+                                #f)))
+                       filters)))))
+
+(define (opensmtpd-configuration-listen->string string)
+  (string-append
+   "include \"" string "\"\n"))
+
+(define (opensmtpd-configuration-srs->string record)
+  (let ([key (opensmtpd-srs-configuration-key record)]
+        [backup-key (opensmtpd-srs-configuration-backup-key record)]
+        [ttl-delay (opensmtpd-srs-configuration-ttl-delay record)])
+    (string-append
+     (variable->string key #:append "srs key " #:postpend "\n")
+     (variable->string backup-key #:append "srs key backup " #:postpend "\n")
+     (variable->string ttl-delay #:append "srs ttl " #:postpend "\n")
+     "\n")))
+
+;; TODO make sure all options here work!  I just fixed limit-max-rcpt!
+(define (opensmtpd-smtp-configuration->string record)
+  (let ([ciphers (opensmtpd-smtp-configuration-ciphers record)]
+        [limit-max-mails (opensmtpd-smtp-configuration-limit-max-mails record)]
+        [limit-max-rcpt (opensmtpd-smtp-configuration-limit-max-rcpt record)]
+        [max-message-size (opensmtpd-smtp-configuration-max-message-size record)]
+        [sub-addr-delim (opensmtpd-smtp-configuration-sub-addr-delim record)])
+    (string-append
+     (variable->string ciphers #:append "smtp ciphers " #:postpend "\n")
+     (variable->string limit-max-mails #:append "smtp limit max-mails " #:postpend "\n")
+     (variable->string limit-max-rcpt #:append "smtp limit max-rcpt " #:postpend "\n")
+     (variable->string max-message-size #:append "smtp max-message-size " #:postpend "\n")
+     (variable->string sub-addr-delim #:append "smtp sub-addr-delim " #:postpend "\n")
+     "\n")))
+
+(define (opensmtpd-configuration-queue->string record)
+  (let ([compression (opensmtpd-queue-configuration-compression record)]
+        [encryption (opensmtpd-queue-configuration-encryption record)]
+        [ttl-delay (opensmtpd-queue-configuration-ttl-delay record)])
+    (string-append
+     (if compression
+         "queue compression\n"
+         "")
+     (if encryption
+         (string-append
+          "queue encryption "
+          (if (not (boolean? encryption))
+              encryption
+              "")
+          "\n")
+         "")
+     (if ttl-delay
+         (string-append "queue ttl" ttl-delay "\n")
+         ""))))
+
+;; build a list of <opensmtpd-action> from
+;; opensmtpd-configuration-matches, which is a list of <opensmtpd-match-configuration>.
+;; Each <opensmtpd-match-configuration> has a fieldname 'action', which accepts an <opensmtpd-action>.
+(define (get-opensmtpd-actions record)
+  (define opensmtpd-actions
+    (let loop ([list (opensmtpd-configuration-matches record)])
+      (if (null? list)
+          '()
+          (cons (opensmtpd-match-configuration-action (car list))
+                (loop (cdr list))))))
+  (delete-duplicates (append opensmtpd-actions)))
+
+;; build a list of opensmtpd-pki-configurations from
+;; opensmtpd-configuration-listen-ons and
+;; get-opensmtpd-actions
+(define (get-opensmtpd-pki-configurations record)
+  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT have an opensmtpd-action-relay-configuration?
+  ;; I think so.  And if it did NOT have a relay configuration, then action-pkis would be '() when
+  ;; it needs to be #f.  because if the opensmtpd-configuration has NO pkis, then this function will
+  ;; return '(), when it should return #f.  If it returns '(), then opensmtpd-configuration-fieldname->string will
+  ;; print the string "\n" instead of ""
+  (define action-pkis
+    (let loop1 ([list (get-opensmtpd-actions record)])
+      (if (null? list)
+          '()
+          (if (and (opensmtpd-action-relay-configuration? (car list))
+                   (opensmtpd-action-relay-configuration-pki (car list)))
+              (cons (opensmtpd-action-relay-configuration-pki (car list))
+                    (loop1 (cdr list)))
+              (loop1 (cdr list))))))
+  ;; FIXME/TODO/maybe/wishlist
+  ;; this could be #f aka left blank. aka there are no listen-ons records with pkis.
+  ;; aka there are no lines in the configuration like:
+  ;; listen on eth0 tls pki smtp.gnucode.me in that case the smtpd.conf will have an extra "\n"
+  (define listen-on-pkis
+    (let loop2 ([list (opensmtpd-configuration-listen-ons record)])
+      (if (null? list)
+          '()
+          (if (opensmtpd-listen-on-configuration-pki (car list))
+              (cons (opensmtpd-listen-on-configuration-pki (car list))
+                    (loop2 (cdr list)))
+              (loop2 (cdr list))))))
+  (delete-duplicates (append action-pkis listen-on-pkis)))
+
+;; takes in a <opensmtpd-configuration> and returns a list whose elements are <opensmtpd-filter-configuration>,
+;; <opensmtpd-filter-phase-configuration>, and a filter-chain.
+;; It returns a list of <opensmtpd-filter-configuration> and/or <opensmtpd-filter-phase-configuration>
+;; here's an example of what this procedure might return:
+;; (list (opensmtpd-filter-configuration...) (opensmtpd-filter-phase-configuration ...)
+;;       (openmstpd-filter ...) (opensmtpd-filter-phase-configuration ...)
+;;       ;; this next list is a filter-chain.
+;;       (list (opensmtpd-filter-phase-configuration ...) (opensmtpd-filter-configuration...)))
+;;
+;; This procedure handles filter chains a little odd.
+(define (get-opensmtpd-filters record)
+  (define list-of-listen-on-records (if (opensmtpd-configuration-listen-ons record)
+                                        (opensmtpd-configuration-listen-ons record)
+                                        '()))
+
+  (define listen-on-socket-filters
+    (if (opensmtpd-listen-on-socket-configuration-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        (opensmtpd-listen-on-socket-configuration-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        '()))
+
+    (delete-duplicates
+     (append (remove boolean?
+                     (map-in-order (lambda (listen-on-record) ; get the filters found in the <listen-on-record>s
+                                     (if (and (opensmtpd-listen-on-configuration-filters listen-on-record)
+                                              (= 1 (length (opensmtpd-listen-on-configuration-filters
+                                                            listen-on-record))))
+                                         (car (opensmtpd-listen-on-configuration-filters listen-on-record))
+                                         (opensmtpd-listen-on-configuration-filters listen-on-record)))
+                                   list-of-listen-on-records))
+             listen-on-socket-filters)))
+
+(define (flatten . lst)
+  "Return a list that recursively concatenates all sub-lists of LST."
+  (define (flatten1 head out)
+    (if (list? head)
+        (fold-right flatten1 out head)
+        (cons head out)))
+  (fold-right flatten1 '() lst))
+
+;; This function takes in a record, or list, or anything, and returns
+;; a list of <opensmtpd-table-configuration>s assuming the thing you passed into it had
+;; any <opensmtpd-table-configuration>s.
+;;
+;; is object record? call func on it's fieldnames
+;; is object list? loop through it's fieldnames calling func on it's records
+;; is object #f or string? or '()? -> #f
+(define (get-opensmtpd-tables value)
+  (delete-duplicates
+   (remove boolean? (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+               (cond ((opensmtpd-table-configuration? value)
+                      value)
+                     ((record? value)
+                      (let* ([record-type (record-type-descriptor value)]
+                             [list-of-record-fieldnames (record-type-fields record-type)])
+                        (map (lambda (fieldname)
+                               (get-opensmtpd-tables ((record-accessor record-type fieldname) value)))
+                             list-of-record-fieldnames)))
+                     ((and (list? value) (not (null? value)))
+                      (map get-opensmtpd-tables value))
+                     (else #f))))))
+
+(define (opensmtpd-configuration-fieldname->string record fieldname-accessor record->string)
+  (if (fieldname-accessor record)
+      (begin
+        (string-append
+         (list-of-records->string (fieldname-accessor record) record->string) "\n"))
+      ""))
+
+(define (list-of-records->string list-of-records record->string)
+  (string-append
+   (cond [(not (list? list-of-records))
+          (record->string list-of-records)]
+         [else
+          (let loop ([list list-of-records])
+            (if (null? list)
+                ""
+                (string-append
+                 (record->string (car list))
+                 (loop (cdr list)))))])))
+
+
+;; FIXME/TODO should I use format here srfi-28 ?
+;; web.scm nginx does a (format #f "string" "another string")
+;; this could be a list like (list (file-append opensmtpd-dkimsign "/libexec/filter") "-d gnucode.me -s /path/to/selector.cert")
+;; Then opensmtpd-configuration->mixed-text-file could be rewritten to be something like
+;; (mixed-text-file (eval `(string-append (opensmtpd-configuration-fieldname->string ...)) (gnu services mail)))
+(define (opensmtpd-configuration->mixed-text-file record)
+  ;; should I use this named let, or should I give this a name, or not use it at all...
+  ;; eg: (write-all-fieldnames (list (cons fieldname fieldname->string) (cons fieldname2 fieldname->string)))
+  ;; (let loop ([list (list (cons opensmtpd-configuration-includes (lambda (string)
+  ;;                                                                 (string-append
+  ;;                                                                  "include \"" string "\"\n")))
+  ;;                        (cons opensmtpd-configuration-smtp opensmtpd-smtp->string)
+  ;;                        (cons opensmtpd-configuration-srs opensmtpd-srs->string))])
+  ;;   (if (null? list)
+  ;;       ""
+  ;;       (string-append (opensmtpd-configuration-fieldname->string record
+  ;;                                                                 (caar list)
+  ;;                                                                 (cdar list))
+  ;;                      (loop (cdr list)))))
+
+  (mixed-text-file "opensmtpd.conf"
+                   (string-append
+                    ;; write out the includes
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-includes
+                                                               opensmtpd-configuration-listen->string)
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-bounce
+                                                               (lambda (%bounce)
+                                                                 (if %bounce
+                                                                     (list-of-strings->string %bounce)
+                                                                     "")))
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-smtp
+                                                               opensmtpd-smtp-configuration->string)
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-srs
+                                                               opensmtpd-configuration-srs->string)
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-queue
+                                                               opensmtpd-configuration-queue->string)
+                    ;; write out the mta-max-deferred
+                    (opensmtpd-configuration-fieldname->string
+                     record opensmtpd-configuration-mta-max-deferred
+                     (lambda (var)
+                       (string-append "mta max-deferred "
+                                      (number->string (opensmtpd-configuration-mta-max-deferred record)) "\n")))
+                    ;;write out all the tables
+                    (opensmtpd-configuration-fieldname->string record get-opensmtpd-tables opensmtpd-table-configuration->string)
+                    ;; TODO should I change the below line of code into these two lines of code?
+                    ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-filter-phase->string)
+                    ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
+                    ;; write out all the filters
+                    (opensmtpd-filters->string (get-opensmtpd-filters record))
+                    ;; write out all the cas
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-cas opensmtpd-ca-configuration->string)
+                    ;; write out all the pkis
+                    (opensmtpd-configuration-fieldname->string record get-opensmtpd-pki-configurations opensmtpd-pki-configuration->string)
+                    ;; write all of the listen-on-records
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-ons
+                                                               opensmtpd-listen-on-configuration->string)
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-on-socket
+                                                               opensmtpd-listen-on-socket-configuration->string)
+                    ;; write all the actions
+                    (opensmtpd-configuration-fieldname->string record get-opensmtpd-actions
+                                                               opensmtpd-action->string)
+                    ;; write all of the matches
+                    (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-matches opensmtpd-match-configuration->string))))
+
 
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "
-- 
2.36.1





^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration
  2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
  2022-06-17 21:54 ` [bug#56046] [PATCH] gnu: services: opensmtpd-records-task-list.org: Some notes about how I thought about building this service. And some additional task lists, as well as the WIP documentation Joshua Branson via Guix-patches via
  2022-07-04 21:17 ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2 Joshua Branson via Guix-patches via
@ 2022-07-05 21:36 ` jbranso--- via Guix-patches via
  2022-10-24 17:30 ` [bug#56046] [Patch master v2] services (opensmtpd): " Joshua Branson via Guix-patches via
                   ` (2 subsequent siblings)
  5 siblings, 0 replies; 23+ messages in thread
From: jbranso--- via Guix-patches via @ 2022-07-05 21:36 UTC (permalink / raw)
  To: 56046

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Here is a video link that may help the first reviewer:

https://video.hardlimit.com/w/ixE7Tc1pCqpP3BgriRbYA5 (https://video.hardlimit.com/w/ixE7Tc1pCqpP3BgriRbYA5)
The video walks you through how to play with an example configuration in emacs-geiser.

Thanks,

Joshua

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^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2
  2022-07-04 21:17 ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2 Joshua Branson via Guix-patches via
@ 2022-07-06  4:27   ` Liliana Marie Prikler
  2022-07-06 21:51   ` jbranso--- via Guix-patches via
  1 sibling, 0 replies; 23+ messages in thread
From: Liliana Marie Prikler @ 2022-07-06  4:27 UTC (permalink / raw)
  To: Joshua Branson, 56046

Am Montag, dem 04.07.2022 um 17:17 -0400 schrieb Joshua Branson:
> Openmstpd-configuration may only be configured by a config-file. 
> This
> patch, enables one to configure opensmtpd by using some guile record
> types (defined via define-record-type*).
> 
> * gnu/services/mail.scm:  New records (opensmtpd-table-
> configuration),
> (opensmtpd-ca-configuration),
> (opensmtpd-pki-configuration),
> (opensmtpd-action-local-delivery-configuration),
> (opensmtpd-maildir-configuration),
> (opensmtpd-mda-configuration),
> (opensmtpd-action-relay-configuration),
> (opensmtpd-option-configuration),
> (opensmtpd-filter-phase-configuration),
> (opensmtpd-filter-configuration),
> (opensmtpd-listen-on-configuration),
> (opensmtpd-listen-on-socket-configuration),
> (opensmtpd-match-configuration),
> (opensmtpd-smtp-configuration),
> (opensmtpd-srs-configuration),
> (opensmtpd-queue-configuration), and
> (opensmtpd-configuration).
Not a ChangeLog.
> New procedures: false?, is-value-right-type, add-comma-or-string,
> file-exists?, list-of-procedures->string, string-in-list?, my-
> sanitize,
> opensmtpd-filter-chain?, throw-error-duplicate-option,
> sanitize-list-of-options-for-match-configuration, sanitize-filters,
> list-has-duplicates-or-non-filters?,
> filter-phase-has-message-and-value?,
> filter-phase-decision-lacks-proper-message?,
> filter-phase-lacks-proper-value?,
> filter-phase-has-incorrect-junk-or-bypass?,
> filter-phase-junks-after-commit?,
> list-of-unique-filter-or-filter-phase?, throw-error,
> contains-duplicate?, list-of-type?, list-of-strings?,
> list-of-unique-opensmtpd-option-configuration?,
> list-of-opensmtpd-ca-configuration?,
> list-of-opensmtpd-pki-configuration?,
> list-of-opensmtpd-listen-on-configuration?,
> list-of-unique-opensmtpd-match-configuration?, list-of-strings-
> >string,
> assoc-list? assoc-list, variable->string,
> table-whose-data-are-assoc-list?,
> table-whose-data-are-a-list-of-strings?, assoc-list->string,
> opensmtpd-table-configuration->string,
> opensmtpd-listen-on-configuration->string,
> opensmtpd-listen-on-socket-configuration->string,
> opensmtpd-action-relay-configuration->string,
> opensmtpd-lmtp-configuration->string,
> opensmtpd-mda-configuration->string,
> opensmtpd-maildir-configuration->string,
> opensmtpd-action-local-delivery-configuration->string,
> opensmtpd-action->string, opensmtpd-option-configuration->string,
> opensmtpd-match-configuration->string,
> opensmtpd-ca-configuration->string, opensmtpd-pki-configuration-
> >string,
> generate-filter-chain-name, opensmtpd-filter-chain->string,
> opensmtpd-filter-phase-configuration->string, opensmtpd-filters-
> >string,
> opensmtpd-configuration-listen->string,
> opensmtpd-configuration-srs->string,
> opensmtpd-smtp-configuration->string,
> opensmtpd-configuration-queue->string, get-opensmtpd-actions,
> get-opensmtpd-pki-configurations, get-opensmtpd-filters, flatten,
> get-opensmtpd-tables, opensmtpd-configuration-fieldname->string,
> list-of-records->string, opensmtpd-configuration->mixed-text-file.
Neither is this.
> * doc/guix.texi added documentation for the new records for
> opensmtpd.
Or this.
> ---
>  doc/guix.texi         | 1051 ++++++++++++++++++++-
>  gnu/services/mail.scm | 2016
> ++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 3056 insertions(+), 11 deletions(-)
> 
> diff --git a/doc/guix.texi b/doc/guix.texi
> index eda0956260..e8564240d1 100644
> --- a/doc/guix.texi
> +++ b/doc/guix.texi
> @@ -24849,14 +24849,59 @@ could instantiate a dovecot service like
> this:
>  @subsubheading OpenSMTPD Service
>  
>  @deffn {Scheme Variable} opensmtpd-service-type
> -This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
> -service, whose value should be an @code{opensmtpd-configuration}
> object
> -as in this example:
> -
> -@lisp
> -(service opensmtpd-service-type
> -         (opensmtpd-configuration
> -           (config-file (local-file "./my-smtpd.conf"))))
> +OpenSMTPD is an easy-to-use mail transfer agent (MTA). Its
> configuration file is
> +throughly documented in @code{man 5 smtpd.conf}. OpenSMTPD
> @strong{listens} for incoming
> +mail and @strong{matches} the mail to @strong{actions}. The
> following records represent those
> +stages:
> +
> +@multitable {aaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
I suggest using fractions here.
> [...]
> +This is a string of one of these options:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
Same here.  Btw. I did not actually check all the doc in between, so I
might be missing something.
> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
Likewise.
> +@multitable {aaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
You get the drill.

> [more doc with strange multitables]
> diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
> index d99743ac31..2a344e303e 100644
> --- a/gnu/services/mail.scm
> +++ b/gnu/services/mail.scm
> @@ -57,8 +57,143 @@ (define-module (gnu services mail)
>              mailbox-configuration
>              namespace-configuration
>  
> +            opensmtpd-table-configuration
> +            opensmtpd-table-configuration?
> +            opensmtpd-table-configuration-name
> +            opensmtpd-table-configuration-file-db
> +            opensmtpd-table-configuration-data
> +
> +            opensmtpd-ca-configuration
> +            opensmtpd-ca-configuration?
> +            opensmtpd-ca-configuration-name
> +            opensmtpd-ca-configuration-file
> +
> +            opensmtpd-pki-configuration
> +            opensmtpd-pki-configuration?
> +            opensmtpd-pki-configuration-domain
> +            opensmtpd-pki-configuration-cert
> +            opensmtpd-pki-configuration-key
> +            opensmtpd-pki-configuration-dhe
> +
> +            opensmtpd-action-local-delivery-configuration
> +            opensmtpd-action-local-delivery-configuration?
> +            opensmtpd-action-local-delivery-configuration-method
> +            opensmtpd-action-local-delivery-configuration-alias
> +            opensmtpd-action-local-delivery-configuration-ttl
> +            opensmtpd-action-local-delivery-configuration-user
> +            opensmtpd-action-local-delivery-configuration-userbase
> +            opensmtpd-action-local-delivery-configuration-virtual
> +            opensmtpd-action-local-delivery-configuration-wrapper
> +
> +            opensmtpd-maildir-configuration
> +            opensmtpd-maildir-configuration?
> +            opensmtpd-maildir-configuration-pathname
> +            opensmtpd-maildir-configuration-junk
> +
> +            opensmtpd-mda-configuration
> +            opensmtpd-mda-configuration-name
> +            opensmtpd-mda-configuration-command
> +
> +            opensmtpd-action-relay-configuration
> +            opensmtpd-action-relay-configuration?
> +            opensmtpd-action-relay-configuration-backup
> +            opensmtpd-action-relay-configuration-backup-mx
> +            opensmtpd-action-relay-configuration-helo
> +            opensmtpd-action-relay-configuration-domain
> +            opensmtpd-action-relay-configuration-host
> +            opensmtpd-action-relay-configuration-pki
> +            opensmtpd-action-relay-configuration-srs
> +            opensmtpd-action-relay-configuration-tls
> +            opensmtpd-action-relay-configuration-auth
> +            opensmtpd-action-relay-configuration-mail-from
> +            opensmtpd-action-relay-configuration-src
> +
> +            opensmtpd-option-configuration
> +            opensmtpd-option-configuration?
> +            opensmtpd-option-configuration-option
> +            opensmtpd-option-configuration-not
> +            opensmtpd-option-configuration-regex
> +            opensmtpd-option-configuration-data
> +
> +            opensmtpd-filter-phase-configuration
> +            opensmtpd-filter-phase-configuration?
> +            opensmtpd-filter-phase-configuration-name
> +            opensmtpd-filter-phase-configuration-phase-name
> +            opensmtpd-filter-phase-configuration-options
> +            opensmtpd-filter-phase-configuration-decision
> +            opensmtpd-filter-phase-configuration-message
> +            opensmtpd-filter-phase-configuration-value
> +
> +            opensmtpd-filter-configuration
> +            opensmtpd-filter-configuration?
> +            opensmtpd-filter-configuration-name
> +            opensmtpd-filter-configuration-proc
> +
> +            opensmtpd-listen-on-configuration
> +            opensmtpd-listen-on-configuration?
> +            opensmtpd-listen-on-configuration-interface
> +            opensmtpd-listen-on-configuration-family
> +            opensmtpd-listen-on-configuration-auth
> +            opensmtpd-listen-on-configuration-auth-optional
> +            opensmtpd-listen-on-configuration-filters
> +            opensmtpd-listen-on-configuration-hostname
> +            opensmtpd-listen-on-configuration-hostnames
> +            opensmtpd-listen-on-configuration-mask-src
> +            opensmtpd-listen-on-configuration-disable-dsn
> +            opensmtpd-listen-on-configuration-pki
> +            opensmtpd-listen-on-configuration-port
> +            opensmtpd-listen-on-configuration-proxy-v2
> +            opensmtpd-listen-on-configuration-received-auth
> +            opensmtpd-listen-on-configuration-senders
> +            opensmtpd-listen-on-configuration-secure-connection
> +            opensmtpd-listen-on-configuration-tag
> +
> +            opensmtpd-listen-on-socket-configuration
> +            opensmtpd-listen-on-socket-configuration?
> +            opensmtpd-listen-on-socket-configuration-filters
> +            opensmtpd-listen-on-socket-configuration-mask-src
> +            opensmtpd-listen-on-socket-configuration-tag
> +
> +            opensmtpd-match-configuration
> +            opensmtpd-match-configuration?
> +            opensmtpd-match-configuration-action
> +            opensmtpd-match-configuration-options
> +
> +            opensmtpd-smtp-configuration
> +            opensmtpd-smtp-configuration?
> +            opensmtpd-smtp-configuration-ciphers
> +            opensmtpd-smtp-configuration-limit-max-mails
> +            opensmtpd-smtp-configuration-limit-max-rcpt
> +            opensmtpd-smtp-configuration-max-message-size
> +            opensmtpd-smtp-configuration-sub-addr-delim character
> +
> +            opensmtpd-srs-configuration
> +            opensmtpd-srs-configuration?
> +            opensmtpd-srs-configuration-key
> +            opensmtpd-srs-configuration-backup-key
> +            opensmtpd-srs-configuration-ttl-delay
> +
> +            opensmtpd-queue-configuration
> +            opensmtpd-queue-configuration?
> +            opensmtpd-queue-configuration-compression
> +            opensmtpd-queue-configuration-encryption
> +            opensmtpd-queue-configuration-ttl-delay
> +
>              opensmtpd-configuration
>              opensmtpd-configuration?
> +            opensmtpd-package
> +            opensmtpd-config-file
> +            opensmtpd-configuration-bounce
> +            opensmtpd-configuration-listen-ons
> +            opensmtpd-configuration-listen-on-socket
> +            opensmtpd-configuration-includes
> +            opensmtpd-configuration-matches
> +            opensmtpd-configuration-mda-wrappers
> +            opensmtpd-configuration-mta-max-deferred
> +            opensmtpd-configuration-srs
> +            opensmtpd-configuration-smtp
> +            opensmtpd-configuration-queue
> +
>              opensmtpd-service-type
>              %default-opensmtpd-config-file
>  
> @@ -1651,13 +1786,1888 @@ (define (generate-dovecot-documentation)
>  ;;; OpenSMTPD.
>  ;;;
>  
> +;; some fieldnames have a default value of #f, which is ok.  They
> cannot have a value of #t.
> +;; for example opensmtpd-table-configuration-data can be #f, BUT NOT
> true.
> +;; my/sanitize procedure tests values to see if they are of the
> right kind.
> +;; procedure false? is needed to allow fields like 'values' to be
> blank, (empty), or #f BUT also
> +;; have a value like a list of strings.
> +(define (false? var)
> +  (eq? #f var))
I'm pretty sure it'd be fine to use not in lieu of false?, even at the
risk of matching nil.

> +;; this procedure takes in a var and a list of procedures.  It loops
> through list of procedures passing in var to each.
> +;; if one procedure returns #t, the function returns true. 
> Otherwise #f.
> +;; TODO for fun rewrite this using map
> +;; If I rewrote it in map, then it may help with sanitizing.
> +;; eg: I could then potentially easily sanitize vars with lambda
> procedures.
> +(define (is-value-right-type? var list-of-procedures record
> fieldname)
> +  (if (null? list-of-procedures)
> +        #f
> +        (cond [(procedure? (car list-of-procedures))
> +               (if ((car list-of-procedures) var)
> +                   #t
> +                   (is-value-right-type? var (cdr list-of-
> procedures) record fieldname))]
> +              [(and (sanitize-configuration? (car list-of-
> procedures))
> +                    (sanitize-configuration-error-if-proc-fails (car
> list-of-procedures))
> +                    (if ((sanitize-configuration-proc (car list-of-
> procedures)) var)
> +                        #t
> +                        (begin
> +                          (apply string-append
> +                                 (sanitize-configuration-error-
> message (car list-of-procedures)))
> +                          (throw 'bad! var))))]
> +              [else (if ((sanitize-configuration-proc (car list-of-
> procedures)) var)
> +                        #t
> +                        (is-value-right-type? var (cdr list-of-
> procedures) record fieldname))])))
Don't we have field sanitizers already that make this obsolete?

> +;; converts strings like this:
> +;; "apple, ham, cherry" -> "apple, ham, or cherry"
> +;; "pineapple" -> "pinneapple".
> +;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
> +(define (add-comma-or string)
> +  (define last-comma-location (string-rindex string #\,))
> +  (if last-comma-location
> +      (if (string-contains string ", or" last-comma-location)
> +          string
> +          (string-replace string ", or" last-comma-location
> +                          (+ 1 last-comma-location)))
> +      string))
> +
> +;; I could test for read-ability of a file, but then I would have to
> +;; test the program as root everytime instead of as a normal user...
> +(define (file-exists? file)
> +(if (string? file)
> +    (access? file F_OK)
> +    #f))
Is this not part of the Guile standard library?

> +(define (list-of-procedures->string procedures)
> +  (define string
> +    (let loop ([procedures procedures])
> +      (if (null? procedures)
> +          ""
> +          (begin
> +            (string-append
> +             (cond [(eq? false? (car procedures))
> +                    "#f , "]
> +                   [(eq? boolean? (car procedures))
> +                    "boolean, "]
> +                   [(eq? string? (car procedures))
> +                    "string, "]
> +                   [(eq? integer? (car procedures))
> +                    "integer, "]
> +                   [(eq? list-of-strings? (car procedures))
> +                    "list of strings, "]
> +                   [(eq? assoc-list? (car procedures))
> +                    "an association list, "]
> +                   [(eq? opensmtpd-pki-configuration? (car
> procedures))
> +                    "an <opensmtpd-pki-configuration> record, "]
> +                   [(eq? opensmtpd-table-configuration? (car
> procedures))
> +                    "an <opensmtpd-table-configuration> record, "]
> +                   [(eq? list-of-unique-opensmtpd-match-
> configuration? (car procedures))
> +                    "a list of unique <opensmtpd-match-
> configuration> records, "]
> +                   [(eq? table-whose-data-are-assoc-list? (car
> procedures))
> +                    (string-append
> +                    "an <opensmtpd-table-configuration> record whose
> fieldname 'values' are an assoc-list \n"
> +                    "(eg: (opensmtpd-table-configuration (name
> \"table\") (data '(\"joshua\" . \"$encrypted$password\")))), ")]
> +                   [(eq? file-exists? (car procedures))
> +                    "file, "]
> +                   [else "has an incorrect value, "])
> +             (loop (cdr procedures)))))))
> +  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
Using a table, map and string-join might be wiser.  If this is the only
place add-comma-or is used, you can replace it by 
(string-append 
  (string-join (butlast strings) ",")
  ", or " (last strings))
where you only need to define butlast.

> +;; TODO can I M-x raise-sexp (string=? string var) in this
> procedure? and get rid of checking
> +;; if the var is a string?  The previous string-in-list? had that
> check.
> +;; (string-in-list? '("hello" 5 "cat")) currently works.  If I M-x
> raise-sexp (string=? string var)
> +;; then it will no longer work.
> +(define (string-in-list? string list)
> +  (primitive-eval (cons 'or (map (lambda (var) (and (string? var)
> (string=? string var))) list))))
Ever heard of member?

> +(define (my/sanitize var record fieldname list-of-procedures)
> +  (if (is-value-right-type? var list-of-procedures record fieldname)
> +      var
> +      (begin
> +        (display (string-append "<" record "> fieldname: '"
> fieldname "' is of type "
> +                                (list-of-procedures->string list-of-
> procedures) "\n"))
> +        (throw 'bad! var))))
> +
> +;; Some example opensmtpd-table-configurations:
> +;;
> +;;  (opensmtpd-table-configuration (name "root accounts") (data
> '(("joshua" . "root@dismail.de") ("joshua" .
> "postmaster@dismail.de"))))
> +;;  (opensmtpd-table-configuration (name "root accounts") (data
> (list "mysite.me" "your-site.com")))
> +;;  TODO should <opensmtpd-table-configuration> support have a
> fieldname 'file'?
> +;;  Or should I change name to name-or-file ?
> +(define-record-type* <opensmtpd-table-configuration>
> +  opensmtpd-table-configuration make-opensmtpd-table-configuration
> +  opensmtpd-table-configuration?
> +  this-record
> +  (name opensmtpd-table-configuration-name ;; string
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-table-configuration"
> "name" (list string?)))))
> +  (file-db opensmtpd-table-configuration-file-db
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-table-
> configuration" "file-db"
> +                                    (list boolean?)))))
> +  ;; FIXME support an aliasing table as described here:
> +  ;; https://man.openbsd.org/table.5
> +  ;; One may have to use the record file for this.  I don't think
> tables support a table like this:
> +  ;; table "name" { joshua =
> joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root =
> root@gnucode.me }
> +  ;; If values is an absolute filename, then it will use said
> filename to house the table info.
> +  ;; filename must be an absolute filename.
> +  (data opensmtpd-table-configuration-data
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-table-
> configuration" "values"
> +                                   (list file-exists? list-of-
> strings? assoc-list?)))))
> +  ;; is a list of values or key values
> +  ;; eg: (list "mysite.me" "your-site.com")
> +  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" .
> "james@gnu.org"))
> +  ;; I am currently making these values be as assocation list of
> strings only.
> +  ;; FIXME should I allow a var like this?
> +  ;; (list (cons "gnucode.me" 234.949.392.23))
> +  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
> +  ;; (opensmtpd-table-configuration-type record) returns the values'
> type.  The user SHOULD NEVER set the type.
> +  ;; TODO jpoiret: on irc reccomends that I just use an outside
> function to determine fieldname 'values', type.
> +  ;; it would be "simpler" and possibly easier for the next person
> working on this code to understand what is happening.
> +  (type opensmtpd-table-configuration-type
> +        (default #f)
> +        (thunked)
> +        (sanitize (lambda (var)
> +                    (cond [(opensmtpd-table-configuration-data this-
> record)
> +                           (if (list-of-strings? (opensmtpd-table-
> configuration-data this-record))
> +                               (quote list-of-strings)
> +                               (quote assoc-list))]
Just a quick side note, we don't usually intermix [ and (.  It's all (.
> [skipping a bit of stuff, may check later...]
> +(define-record-type* <opensmtpd-option-configuration>
> +  opensmtpd-option-configuration make-opensmtpd-option-configuration
> +  opensmtpd-option-configuration?
> +  (option opensmtpd-option-configuration-option
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (if (and (string? var)
> +                               (or (string-in-list? var (list
> "fcrdns" "rdns"
> +                                                          "src"
> "helo"
> +                                                          "auth"
> "mail-from"
> +                                                          "rcpt-to"
> +                                                          "for"
> +                                                          "for any"
> "for local"
> +                                                          "for
> domain" "for rcpt-to"
> +                                                          "from any"
> "from auth"
> +                                                          "from
> local" "from mail-from"
> +                                                          "from
> rdns" "from socket"
> +                                                          "from src"
> "auth"
> +                                                          "helo"
> "mail-from"
> +                                                          "rcpt-to"
> "tag" "tls"
> +                                                          ))))
> +                          var
> +                          (begin
> +                            (display (string-append "<opensmtpd-
> option-configuration> fieldname: 'option' is of type \n"
> +                                                    "string.  The
> string can be either 'fcrdns', \n"
> +                                                    " 'rdns', 'src',
> 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
> +                                                    "'for', 'for
> any', 'for local', 'for domain', 'for rcpt-to', \n"
> +                                                    "'from any',
> 'from auth', 'from local', 'from mail-from', 'from rdns', 'from
> socket', \n"
> +                                                    "'from src',
> 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"
> +                                                    ))
> +                            (throw 'bad! var))))))
This is a little verbose for what it does.

> +(define-record-type* <opensmtpd-listen-on-configuration>
What is a "listen-on"?
> +(define-record-type* <opensmtpd-listen-on-socket-configuration-
> configuration>
Again, could this just be <opensmtpd-socket-configuration>?
>  (define-record-type* <opensmtpd-configuration>
>    opensmtpd-configuration make-opensmtpd-configuration
>    opensmtpd-configuration?
> -  (package     opensmtpd-configuration-package
> -               (default opensmtpd))
> +  (package opensmtpd-configuration-package
> +           (default opensmtpd))
>    (config-file opensmtpd-configuration-config-file
> -               (default %default-opensmtpd-config-file)))
> +               (default #f))
> +  ;; FIXME/TODO should I include a admd authservid entry?
> +
> +  ;; TODO sanitize this properly with perhaps a <sanitize-
> configuration>.
> +  (bounce opensmtpd-configuration-bounce
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-configuration"
> "bounce"
> +                                   (list false? list?)))))
> +  (cas opensmtpd-configuration-cas
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-configuration" "cas"
> +                                (list false? list-of-opensmtpd-ca-
> configuration?)))))
> +  ;; list of many records of type opensmtpd-listen-on-configuration
> +  (listen-ons opensmtpd-configuration-listen-ons
What does opensmtpd acutally listen on?


> [...]
Too much to check, too little time.  Maybe return later.




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2
  2022-07-04 21:17 ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2 Joshua Branson via Guix-patches via
  2022-07-06  4:27   ` Liliana Marie Prikler
@ 2022-07-06 21:51   ` jbranso--- via Guix-patches via
  2022-07-07  4:25     ` Liliana Marie Prikler
  2022-07-07 17:27     ` jbranso--- via Guix-patches via
  1 sibling, 2 replies; 23+ messages in thread
From: jbranso--- via Guix-patches via @ 2022-07-06 21:51 UTC (permalink / raw)
  To: Liliana Marie Prikler, 56046

July 6, 2022 12:27 AM, "Liliana Marie Prikler" <liliana.prikler@gmail.com> wrote:

> Am Montag, dem 04.07.2022 um 17:17 -0400 schrieb Joshua Branson:
> 
>> Openmstpd-configuration may only be configured by a config-file. 
>> This
>> patch, enables one to configure opensmtpd by using some guile record
>> types (defined via define-record-type*).
>> 
>> * gnu/services/mail.scm:  New records (opensmtpd-table-
>> configuration),
>> (opensmtpd-ca-configuration),
>> (opensmtpd-pki-configuration),
>> (opensmtpd-action-local-delivery-configuration),
>> (opensmtpd-maildir-configuration),
>> (opensmtpd-mda-configuration),
>> (opensmtpd-action-relay-configuration),
>> (opensmtpd-option-configuration),
>> (opensmtpd-filter-phase-configuration),
>> (opensmtpd-filter-configuration),
>> (opensmtpd-listen-on-configuration),
>> (opensmtpd-listen-on-socket-configuration),
>> (opensmtpd-match-configuration),
>> (opensmtpd-smtp-configuration),
>> (opensmtpd-srs-configuration),
>> (opensmtpd-queue-configuration), and
>> (opensmtpd-configuration).
> 
> Not a ChangeLog.

I'll actually go and learn how to do that thanks.

> 
>> New procedures: false?, is-value-right-type, add-comma-or-string,
>> file-exists?, list-of-procedures->string, string-in-list?, my-
>> sanitize,
>> opensmtpd-filter-chain?, throw-error-duplicate-option,
>> sanitize-list-of-options-for-match-configuration, sanitize-filters,
>> list-has-duplicates-or-non-filters?,
>> filter-phase-has-message-and-value?,
>> filter-phase-decision-lacks-proper-message?,
>> filter-phase-lacks-proper-value?,
>> filter-phase-has-incorrect-junk-or-bypass?,
>> filter-phase-junks-after-commit?,
>> list-of-unique-filter-or-filter-phase?, throw-error,
>> contains-duplicate?, list-of-type?, list-of-strings?,
>> list-of-unique-opensmtpd-option-configuration?,
>> list-of-opensmtpd-ca-configuration?,
>> list-of-opensmtpd-pki-configuration?,
>> list-of-opensmtpd-listen-on-configuration?,
>> list-of-unique-opensmtpd-match-configuration?, list-of-strings-
>> string,
>> assoc-list? assoc-list, variable->string,
>> table-whose-data-are-assoc-list?,
>> table-whose-data-are-a-list-of-strings?, assoc-list->string,
>> opensmtpd-table-configuration->string,
>> opensmtpd-listen-on-configuration->string,
>> opensmtpd-listen-on-socket-configuration->string,
>> opensmtpd-action-relay-configuration->string,
>> opensmtpd-lmtp-configuration->string,
>> opensmtpd-mda-configuration->string,
>> opensmtpd-maildir-configuration->string,
>> opensmtpd-action-local-delivery-configuration->string,
>> opensmtpd-action->string, opensmtpd-option-configuration->string,
>> opensmtpd-match-configuration->string,
>> opensmtpd-ca-configuration->string, opensmtpd-pki-configuration-
>> string,
>> generate-filter-chain-name, opensmtpd-filter-chain->string,
>> opensmtpd-filter-phase-configuration->string, opensmtpd-filters-
>> string,
>> opensmtpd-configuration-listen->string,
>> opensmtpd-configuration-srs->string,
>> opensmtpd-smtp-configuration->string,
>> opensmtpd-configuration-queue->string, get-opensmtpd-actions,
>> get-opensmtpd-pki-configurations, get-opensmtpd-filters, flatten,
>> get-opensmtpd-tables, opensmtpd-configuration-fieldname->string,
>> list-of-records->string, opensmtpd-configuration->mixed-text-file.
> 
> Neither is this.
>> * doc/guix.texi added documentation for the new records for
>> opensmtpd.
> 
> Or this.
> 
>> ---
>> doc/guix.texi         | 1051 ++++++++++++++++++++-
>> gnu/services/mail.scm | 2016
>> ++++++++++++++++++++++++++++++++++++++++-
>> 2 files changed, 3056 insertions(+), 11 deletions(-)
>> 
>> diff --git a/doc/guix.texi b/doc/guix.texi
>> index eda0956260..e8564240d1 100644
>> --- a/doc/guix.texi
>> +++ b/doc/guix.texi
>> @@ -24849,14 +24849,59 @@ could instantiate a dovecot service like
>> this:
>> @subsubheading OpenSMTPD Service
>> 
>> @deffn {Scheme Variable} opensmtpd-service-type
>> -This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
>> -service, whose value should be an @code{opensmtpd-configuration}
>> object
>> -as in this example:
>> -
>> -@lisp
>> -(service opensmtpd-service-type
>> -         (opensmtpd-configuration
>> -           (config-file (local-file "./my-smtpd.conf"))))
>> +OpenSMTPD is an easy-to-use mail transfer agent (MTA). Its
>> configuration file is
>> +throughly documented in @code{man 5 smtpd.conf}. OpenSMTPD
>> @strong{listens} for incoming
>> +mail and @strong{matches} the mail to @strong{actions}. The
>> following records represent those
>> +stages:
>> +
>> +@multitable {aaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> 
> I suggest using fractions here.

I'll take a look at the texinfo fractions bit.  This was all generated 
from an org-mode document.

> 
>> [...]
>> +This is a string of one of these options:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> 
> Same here. Btw. I did not actually check all the doc in between, so I
> might be missing something.
>> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> 
> Likewise.
>> +@multitable {aaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> 
> You get the drill.
> 
>> [more doc with strange multitables]
>> diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
>> index d99743ac31..2a344e303e 100644
>> --- a/gnu/services/mail.scm
>> +++ b/gnu/services/mail.scm
>> @@ -57,8 +57,143 @@ (define-module (gnu services mail)
>> mailbox-configuration
>> namespace-configuration
>> 
>> +            opensmtpd-table-configuration
>> +            opensmtpd-table-configuration?
>> +            opensmtpd-table-configuration-name
>> +            opensmtpd-table-configuration-file-db
>> +            opensmtpd-table-configuration-data
>> +
>> +            opensmtpd-ca-configuration
>> +            opensmtpd-ca-configuration?
>> +            opensmtpd-ca-configuration-name
>> +            opensmtpd-ca-configuration-file
>> +
>> +            opensmtpd-pki-configuration
>> +            opensmtpd-pki-configuration?
>> +            opensmtpd-pki-configuration-domain
>> +            opensmtpd-pki-configuration-cert
>> +            opensmtpd-pki-configuration-key
>> +            opensmtpd-pki-configuration-dhe
>> +
>> +            opensmtpd-action-local-delivery-configuration
>> +            opensmtpd-action-local-delivery-configuration?
>> +            opensmtpd-action-local-delivery-configuration-method
>> +            opensmtpd-action-local-delivery-configuration-alias
>> +            opensmtpd-action-local-delivery-configuration-ttl
>> +            opensmtpd-action-local-delivery-configuration-user
>> +            opensmtpd-action-local-delivery-configuration-userbase
>> +            opensmtpd-action-local-delivery-configuration-virtual
>> +            opensmtpd-action-local-delivery-configuration-wrapper
>> +
>> +            opensmtpd-maildir-configuration
>> +            opensmtpd-maildir-configuration?
>> +            opensmtpd-maildir-configuration-pathname
>> +            opensmtpd-maildir-configuration-junk
>> +
>> +            opensmtpd-mda-configuration
>> +            opensmtpd-mda-configuration-name
>> +            opensmtpd-mda-configuration-command
>> +
>> +            opensmtpd-action-relay-configuration
>> +            opensmtpd-action-relay-configuration?
>> +            opensmtpd-action-relay-configuration-backup
>> +            opensmtpd-action-relay-configuration-backup-mx
>> +            opensmtpd-action-relay-configuration-helo
>> +            opensmtpd-action-relay-configuration-domain
>> +            opensmtpd-action-relay-configuration-host
>> +            opensmtpd-action-relay-configuration-pki
>> +            opensmtpd-action-relay-configuration-srs
>> +            opensmtpd-action-relay-configuration-tls
>> +            opensmtpd-action-relay-configuration-auth
>> +            opensmtpd-action-relay-configuration-mail-from
>> +            opensmtpd-action-relay-configuration-src
>> +
>> +            opensmtpd-option-configuration
>> +            opensmtpd-option-configuration?
>> +            opensmtpd-option-configuration-option
>> +            opensmtpd-option-configuration-not
>> +            opensmtpd-option-configuration-regex
>> +            opensmtpd-option-configuration-data
>> +
>> +            opensmtpd-filter-phase-configuration
>> +            opensmtpd-filter-phase-configuration?
>> +            opensmtpd-filter-phase-configuration-name
>> +            opensmtpd-filter-phase-configuration-phase-name
>> +            opensmtpd-filter-phase-configuration-options
>> +            opensmtpd-filter-phase-configuration-decision
>> +            opensmtpd-filter-phase-configuration-message
>> +            opensmtpd-filter-phase-configuration-value
>> +
>> +            opensmtpd-filter-configuration
>> +            opensmtpd-filter-configuration?
>> +            opensmtpd-filter-configuration-name
>> +            opensmtpd-filter-configuration-proc
>> +
>> +            opensmtpd-listen-on-configuration
>> +            opensmtpd-listen-on-configuration?
>> +            opensmtpd-listen-on-configuration-interface
>> +            opensmtpd-listen-on-configuration-family
>> +            opensmtpd-listen-on-configuration-auth
>> +            opensmtpd-listen-on-configuration-auth-optional
>> +            opensmtpd-listen-on-configuration-filters
>> +            opensmtpd-listen-on-configuration-hostname
>> +            opensmtpd-listen-on-configuration-hostnames
>> +            opensmtpd-listen-on-configuration-mask-src
>> +            opensmtpd-listen-on-configuration-disable-dsn
>> +            opensmtpd-listen-on-configuration-pki
>> +            opensmtpd-listen-on-configuration-port
>> +            opensmtpd-listen-on-configuration-proxy-v2
>> +            opensmtpd-listen-on-configuration-received-auth
>> +            opensmtpd-listen-on-configuration-senders
>> +            opensmtpd-listen-on-configuration-secure-connection
>> +            opensmtpd-listen-on-configuration-tag
>> +
>> +            opensmtpd-listen-on-socket-configuration
>> +            opensmtpd-listen-on-socket-configuration?
>> +            opensmtpd-listen-on-socket-configuration-filters
>> +            opensmtpd-listen-on-socket-configuration-mask-src
>> +            opensmtpd-listen-on-socket-configuration-tag
>> +
>> +            opensmtpd-match-configuration
>> +            opensmtpd-match-configuration?
>> +            opensmtpd-match-configuration-action
>> +            opensmtpd-match-configuration-options
>> +
>> +            opensmtpd-smtp-configuration
>> +            opensmtpd-smtp-configuration?
>> +            opensmtpd-smtp-configuration-ciphers
>> +            opensmtpd-smtp-configuration-limit-max-mails
>> +            opensmtpd-smtp-configuration-limit-max-rcpt
>> +            opensmtpd-smtp-configuration-max-message-size
>> +            opensmtpd-smtp-configuration-sub-addr-delim character
>> +
>> +            opensmtpd-srs-configuration
>> +            opensmtpd-srs-configuration?
>> +            opensmtpd-srs-configuration-key
>> +            opensmtpd-srs-configuration-backup-key
>> +            opensmtpd-srs-configuration-ttl-delay
>> +
>> +            opensmtpd-queue-configuration
>> +            opensmtpd-queue-configuration?
>> +            opensmtpd-queue-configuration-compression
>> +            opensmtpd-queue-configuration-encryption
>> +            opensmtpd-queue-configuration-ttl-delay
>> +
>> opensmtpd-configuration
>> opensmtpd-configuration?
>> +            opensmtpd-package
>> +            opensmtpd-config-file
>> +            opensmtpd-configuration-bounce
>> +            opensmtpd-configuration-listen-ons
>> +            opensmtpd-configuration-listen-on-socket
>> +            opensmtpd-configuration-includes
>> +            opensmtpd-configuration-matches
>> +            opensmtpd-configuration-mda-wrappers
>> +            opensmtpd-configuration-mta-max-deferred
>> +            opensmtpd-configuration-srs
>> +            opensmtpd-configuration-smtp
>> +            opensmtpd-configuration-queue
>> +
>> opensmtpd-service-type
>> %default-opensmtpd-config-file
>> 
>> @@ -1651,13 +1786,1888 @@ (define (generate-dovecot-documentation)
>> ;;; OpenSMTPD.
>> ;;;
>> 
>> +;; some fieldnames have a default value of #f, which is ok.  They
>> cannot have a value of #t.
>> +;; for example opensmtpd-table-configuration-data can be #f, BUT NOT
>> true.
>> +;; my/sanitize procedure tests values to see if they are of the
>> right kind.
>> +;; procedure false? is needed to allow fields like 'values' to be
>> blank, (empty), or #f BUT also
>> +;; have a value like a list of strings.
>> +(define (false? var)
>> +  (eq? #f var))
> 
> I'm pretty sure it'd be fine to use not in lieu of false?, even at the
> risk of matching nil.

Sounds ok.  I may need to double check that there are no places
that have nil values.

> 
>> +;; this procedure takes in a var and a list of procedures.  It loops
>> through list of procedures passing in var to each.
>> +;; if one procedure returns #t, the function returns true. 
>> Otherwise #f.
>> +;; TODO for fun rewrite this using map
>> +;; If I rewrote it in map, then it may help with sanitizing.
>> +;; eg: I could then potentially easily sanitize vars with lambda
>> procedures.
>> +(define (is-value-right-type? var list-of-procedures record
>> fieldname)
>> +  (if (null? list-of-procedures)
>> +        #f
>> +        (cond [(procedure? (car list-of-procedures))
>> +               (if ((car list-of-procedures) var)
>> +                   #t
>> +                   (is-value-right-type? var (cdr list-of-
>> procedures) record fieldname))]
>> +              [(and (sanitize-configuration? (car list-of-
>> procedures))
>> +                    (sanitize-configuration-error-if-proc-fails (car
>> list-of-procedures))
>> +                    (if ((sanitize-configuration-proc (car list-of-
>> procedures)) var)
>> +                        #t
>> +                        (begin
>> +                          (apply string-append
>> +                                 (sanitize-configuration-error-
>> message (car list-of-procedures)))
>> +                          (throw 'bad! var))))]
>> +              [else (if ((sanitize-configuration-proc (car list-of-
>> procedures)) var)
>> +                        #t
>> +                        (is-value-right-type? var (cdr list-of-
>> procedures) record fieldname))])))
> 
> Don't we have field sanitizers already that make this obsolete?
> 
>> +;; converts strings like this:
>> +;; "apple, ham, cherry" -> "apple, ham, or cherry"
>> +;; "pineapple" -> "pinneapple".
>> +;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
>> +(define (add-comma-or string)
>> +  (define last-comma-location (string-rindex string #\,))
>> +  (if last-comma-location
>> +      (if (string-contains string ", or" last-comma-location)
>> +          string
>> +          (string-replace string ", or" last-comma-location
>> +                          (+ 1 last-comma-location)))
>> +      string))
>> +
>> +;; I could test for read-ability of a file, but then I would have to
>> +;; test the program as root everytime instead of as a normal user...
>> +(define (file-exists? file)
>> +(if (string? file)
>> +    (access? file F_OK)
>> +    #f))
> 
> Is this not part of the Guile standard library?

I do not believe that guile has a file-exists? thunk.  
I could use (access? file F_OK) every time, but I think
file-exists? is easier to use.  My two cents.

> 
>> +(define (list-of-procedures->string procedures)
>> +  (define string
>> +    (let loop ([procedures procedures])
>> +      (if (null? procedures)
>> +          ""
>> +          (begin
>> +            (string-append
>> +             (cond [(eq? false? (car procedures))
>> +                    "#f , "]
>> +                   [(eq? boolean? (car procedures))
>> +                    "boolean, "]
>> +                   [(eq? string? (car procedures))
>> +                    "string, "]
>> +                   [(eq? integer? (car procedures))
>> +                    "integer, "]
>> +                   [(eq? list-of-strings? (car procedures))
>> +                    "list of strings, "]
>> +                   [(eq? assoc-list? (car procedures))
>> +                    "an association list, "]
>> +                   [(eq? opensmtpd-pki-configuration? (car
>> procedures))
>> +                    "an <opensmtpd-pki-configuration> record, "]
>> +                   [(eq? opensmtpd-table-configuration? (car
>> procedures))
>> +                    "an <opensmtpd-table-configuration> record, "]
>> +                   [(eq? list-of-unique-opensmtpd-match-
>> configuration? (car procedures))
>> +                    "a list of unique <opensmtpd-match-
>> configuration> records, "]
>> +                   [(eq? table-whose-data-are-assoc-list? (car
>> procedures))
>> +                    (string-append
>> +                    "an <opensmtpd-table-configuration> record whose
>> fieldname 'values' are an assoc-list \n"
>> +                    "(eg: (opensmtpd-table-configuration (name
>> \"table\") (data '(\"joshua\" . \"$encrypted$password\")))), ")]
>> +                   [(eq? file-exists? (car procedures))
>> +                    "file, "]
>> +                   [else "has an incorrect value, "])
>> +             (loop (cdr procedures)))))))
>> +  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
> 
> Using a table, map and string-join might be wiser. If this is the only
> place add-comma-or is used, you can replace it by 
> (string-append
> (string-join (butlast strings) ",")
> ", or " (last strings))
> where you only need to define butlast.

I'll take a look.

> 
>> +;; TODO can I M-x raise-sexp (string=? string var) in this
>> procedure? and get rid of checking
>> +;; if the var is a string?  The previous string-in-list? had that
>> check.
>> +;; (string-in-list? '("hello" 5 "cat")) currently works.  If I M-x
>> raise-sexp (string=? string var)
>> +;; then it will no longer work.
>> +(define (string-in-list? string list)
>> +  (primitive-eval (cons 'or (map (lambda (var) (and (string? var)
>> (string=? string var))) list))))
> 
> Ever heard of member?

Will use it.

> 
>> +(define (my/sanitize var record fieldname list-of-procedures)
>> +  (if (is-value-right-type? var list-of-procedures record fieldname)
>> +      var
>> +      (begin
>> +        (display (string-append "<" record "> fieldname: '"
>> fieldname "' is of type "
>> +                                (list-of-procedures->string list-of-
>> procedures) "\n"))
>> +        (throw 'bad! var))))
>> +
>> +;; Some example opensmtpd-table-configurations:
>> +;;
>> +;;  (opensmtpd-table-configuration (name "root accounts") (data
>> '(("joshua" . "root@dismail.de") ("joshua" .
>> "postmaster@dismail.de"))))
>> +;;  (opensmtpd-table-configuration (name "root accounts") (data
>> (list "mysite.me" "your-site.com")))
>> +;;  TODO should <opensmtpd-table-configuration> support have a
>> fieldname 'file'?
>> +;;  Or should I change name to name-or-file ?
>> +(define-record-type* <opensmtpd-table-configuration>
>> +  opensmtpd-table-configuration make-opensmtpd-table-configuration
>> +  opensmtpd-table-configuration?
>> +  this-record
>> +  (name opensmtpd-table-configuration-name ;; string
>> +        (default #f)
>> +        (sanitize (lambda (var)
>> +                    (my/sanitize var "opensmtpd-table-configuration"
>> "name" (list string?)))))
>> +  (file-db opensmtpd-table-configuration-file-db
>> +           (default #f)
>> +           (sanitize (lambda (var)
>> +                       (my/sanitize var "opensmtpd-table-
>> configuration" "file-db"
>> +                                    (list boolean?)))))
>> +  ;; FIXME support an aliasing table as described here:
>> +  ;; https://man.openbsd.org/table.5
>> +  ;; One may have to use the record file for this.  I don't think
>> tables support a table like this:
>> +  ;; table "name" { joshua =
>> joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root =
>> root@gnucode.me }
>> +  ;; If values is an absolute filename, then it will use said
>> filename to house the table info.
>> +  ;; filename must be an absolute filename.
>> +  (data opensmtpd-table-configuration-data
>> +          (default #f)
>> +          (sanitize (lambda (var)
>> +                      (my/sanitize var "opensmtpd-table-
>> configuration" "values"
>> +                                   (list file-exists? list-of-
>> strings? assoc-list?)))))
>> +  ;; is a list of values or key values
>> +  ;; eg: (list "mysite.me" "your-site.com")
>> +  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" .
>> "james@gnu.org"))
>> +  ;; I am currently making these values be as assocation list of
>> strings only.
>> +  ;; FIXME should I allow a var like this?
>> +  ;; (list (cons "gnucode.me" 234.949.392.23))
>> +  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
>> +  ;; (opensmtpd-table-configuration-type record) returns the values'
>> type.  The user SHOULD NEVER set the type.
>> +  ;; TODO jpoiret: on irc reccomends that I just use an outside
>> function to determine fieldname 'values', type.
>> +  ;; it would be "simpler" and possibly easier for the next person
>> working on this code to understand what is happening.
>> +  (type opensmtpd-table-configuration-type
>> +        (default #f)
>> +        (thunked)
>> +        (sanitize (lambda (var)
>> +                    (cond [(opensmtpd-table-configuration-data this-
>> record)
>> +                           (if (list-of-strings? (opensmtpd-table-
>> configuration-data this-record))
>> +                               (quote list-of-strings)
>> +                               (quote assoc-list))]
> 
> Just a quick side note, we don't usually intermix [ and (. It's all (.

Yeah I saw that in the coding style.  I'll fix it.

> 
>> [skipping a bit of stuff, may check later...]
>> +(define-record-type* <opensmtpd-option-configuration>
>> +  opensmtpd-option-configuration make-opensmtpd-option-configuration
>> +  opensmtpd-option-configuration?
>> +  (option opensmtpd-option-configuration-option
>> +          (default #f)
>> +          (sanitize (lambda (var)
>> +                      (if (and (string? var)
>> +                               (or (string-in-list? var (list
>> "fcrdns" "rdns"
>> +                                                          "src"
>> "helo"
>> +                                                          "auth"
>> "mail-from"
>> +                                                          "rcpt-to"
>> +                                                          "for"
>> +                                                          "for any"
>> "for local"
>> +                                                          "for
>> domain" "for rcpt-to"
>> +                                                          "from any"
>> "from auth"
>> +                                                          "from
>> local" "from mail-from"
>> +                                                          "from
>> rdns" "from socket"
>> +                                                          "from src"
>> "auth"
>> +                                                          "helo"
>> "mail-from"
>> +                                                          "rcpt-to"
>> "tag" "tls"
>> +                                                          ))))
>> +                          var
>> +                          (begin
>> +                            (display (string-append "<opensmtpd-
>> option-configuration> fieldname: 'option' is of type \n"
>> +                                                    "string.  The
>> string can be either 'fcrdns', \n"
>> +                                                    " 'rdns', 'src',
>> 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
>> +                                                    "'for', 'for
>> any', 'for local', 'for domain', 'for rcpt-to', \n"
>> +                                                    "'from any',
>> 'from auth', 'from local', 'from mail-from', 'from rdns', 'from
>> socket', \n"
>> +                                                    "'from src',
>> 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"
>> +                                                    ))
>> +                            (throw 'bad! var))))))
> 
> This is a little verbose for what it does.

Fair I suppose.  I'll see if I can shorten it.

> 
>> +(define-record-type* <opensmtpd-listen-on-configuration>
> 
> What is a "listen-on"?

"listen-on" refers to the "listen on" in smtpd.conf:
https://man.openbsd.org/smtpd.conf

lan_addr = "192.168.0.1"
listen on $lan_addr
listen on $lan_addr tls auth

>> +(define-record-type* <opensmtpd-listen-on-socket-configuration-
>> configuration>
> 
> Again, could this just be <opensmtpd-socket-configuration>?

I would prefer to have two data types for "listen on" and
"listen on socket".  "listen on socket" only supports 3 options, where
"listen on" supports 19.  

https://man.openbsd.org/smtpd.conf

;;valid record
(openstmpd-listen-on-configuration
  (tag "port-48")
  (port 48))

;;invalid record and will result in an error as it should.
(openstmpd-listen-on-socket-configuration
  (tag "port-48")
  (port 48))

> 
>> (define-record-type* <opensmtpd-configuration>
>> opensmtpd-configuration make-opensmtpd-configuration
>> opensmtpd-configuration?
>> -  (package     opensmtpd-configuration-package
>> -               (default opensmtpd))
>> +  (package opensmtpd-configuration-package
>> +           (default opensmtpd))
>> (config-file opensmtpd-configuration-config-file
>> -               (default %default-opensmtpd-config-file)))
>> +               (default #f))
>> +  ;; FIXME/TODO should I include a admd authservid entry?
>> +
>> +  ;; TODO sanitize this properly with perhaps a <sanitize-
>> configuration>.
>> +  (bounce opensmtpd-configuration-bounce
>> +          (default #f)
>> +          (sanitize (lambda (var)
>> +                      (my/sanitize var "opensmtpd-configuration"
>> "bounce"
>> +                                   (list false? list?)))))
>> +  (cas opensmtpd-configuration-cas
>> +       (default #f)
>> +       (sanitize (lambda (var)
>> +                   (my/sanitize var "opensmtpd-configuration" "cas"
>> +                                (list false? list-of-opensmtpd-ca-
>> configuration?)))))
>> +  ;; list of many records of type opensmtpd-listen-on-configuration
>> +  (listen-ons opensmtpd-configuration-listen-ons
> 
> What does opensmtpd acutally listen on?

From the documentation:

listen on interface [family] [options]
    Listen on the interface for incoming connections, using the same syntax as ifconfig(8). The interface parameter may also be an interface group, an IP address, or a domain name. Listening can optionally be restricted to a specific address family, which can be either inet4 or inet6. 

listen on socket [options]
    Listen for incoming SMTP connections on the Unix domain socket /var/run/smtpd.sock. This is done by default, even if the directive is absent. 

> 
>> [...]
> 
> Too much to check, too little time. Maybe return later.

To summarize the tasks that you have given me are:

1) Write a proper changelog.
2) define "string-in-list?" with member? 
   Are there other procedures that could use this?
3) replace [] with ()
4) Shorten the sanitize procedure for opensmtpd-option-configuration

Thanks for reviewing!

Joshua




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2
  2022-07-06 21:51   ` jbranso--- via Guix-patches via
@ 2022-07-07  4:25     ` Liliana Marie Prikler
  2022-07-07 17:27     ` jbranso--- via Guix-patches via
  1 sibling, 0 replies; 23+ messages in thread
From: Liliana Marie Prikler @ 2022-07-07  4:25 UTC (permalink / raw)
  To: jbranso, 56046

Am Mittwoch, dem 06.07.2022 um 21:51 +0000 schrieb jbranso@dismail.de:
> I do not believe that guile has a file-exists? thunk.  
> I could use (access? file F_OK) every time, but I think
> file-exists? is easier to use.  My two cents.
scheme@(guile-user)> file-exists?
$1 = #<procedure 7fa4d7da6828 at ice-9/boot-9.scm:1971:6 (str)>

> 
> > What is a "listen-on"?
> 
> "listen-on" refers to the "listen on" in smtpd.conf:
> https://man.openbsd.org/smtpd.conf
> 
> lan_addr = "192.168.0.1"
> listen on $lan_addr
> listen on $lan_addr tls auth
Okay, but what would you call that?  An address maybe?

> > > +(define-record-type* <opensmtpd-listen-on-socket-configuration-
> > > configuration>
> > 
> > Again, could this just be <opensmtpd-socket-configuration>?
> 
> I would prefer to have two data types for "listen on" and
> "listen on socket".  "listen on socket" only supports 3 options,
> where "listen on" supports 19.
I am not questioning whether it makes sense to add a configuration
record – it probably does – but whether you're using the best name for
that record.  We are not Java programmers here, a little abstraction
goes a long way.

> From the documentation:
> 
> listen on interface [family] [options]
>     Listen on the interface for incoming connections, using the same
> syntax as ifconfig(8). The interface parameter may also be an
> interface group, an IP address, or a domain name. Listening can
> optionally be restricted to a specific address family, which can be
> either inet4 or inet6. 
> 
> listen on socket [options]
>     Listen for incoming SMTP connections on the Unix domain socket
> /var/run/smtpd.sock. This is done by default, even if the directive
> is absent. 
So you can either have an opensmtp-interface (with family and a bunch
of options) or an opensmtp-socket (with a bunch of options).  Sounds
like a much nicer ontology, doesn't it?

> > > [...]
> > 
> > Too much to check, too little time. Maybe return later.
> 
> To summarize the tasks that you have given me are:
> 
> 1) Write a proper changelog.
> 2) define "string-in-list?" with member? 
>    Are there other procedures that could use this?
> 3) replace [] with ()
> 4) Shorten the sanitize procedure for opensmtpd-option-configuration
5) Review your class names.
I also don't think it makes too much sense to add -configuration for
anything but the top-level configuration record, it just requires you
to type much more configuration than you probably want.

Cheers




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2
  2022-07-06 21:51   ` jbranso--- via Guix-patches via
  2022-07-07  4:25     ` Liliana Marie Prikler
@ 2022-07-07 17:27     ` jbranso--- via Guix-patches via
  2022-07-07 18:20       ` Liliana Marie Prikler
  1 sibling, 1 reply; 23+ messages in thread
From: jbranso--- via Guix-patches via @ 2022-07-07 17:27 UTC (permalink / raw)
  To: Liliana Marie Prikler, 56046

July 7, 2022 2:48 AM, "Liliana Marie Prikler" <liliana.prikler@gmail.com> wrote:

> Am Mittwoch, dem 06.07.2022 um 21:51 +0000 schrieb jbranso@dismail.de:
> 
>> I do not believe that guile has a file-exists? thunk. 
>> I could use (access? file F_OK) every time, but I think
>> file-exists? is easier to use.  My two cents.
> 
> scheme@(guile-user)> file-exists?
> $1 = #<procedure 7fa4d7da6828 at ice-9/boot-9.scm:1971:6 (str)>

ok.  Good to know!

> 
>> What is a "listen-on"?
>> 
>> "listen-on" refers to the "listen on" in smtpd.conf:
>> https://man.openbsd.org/smtpd.conf
>> 
>> lan_addr = "192.168.0.1"
>> listen on $lan_addr
>> listen on $lan_addr tls auth
> 
> Okay, but what would you call that? An address maybe?
> 
>>> +(define-record-type* <opensmtpd-listen-on-socket-configuration-
>>> configuration>
>> 
>> Again, could this just be <opensmtpd-socket-configuration>?
>> 
>> I would prefer to have two data types for "listen on" and
>> "listen on socket".  "listen on socket" only supports 3 options,
>> where "listen on" supports 19.
> 
> I am not questioning whether it makes sense to add a configuration
> record – it probably does – but whether you're using the best name for
> that record. We are not Java programmers here, a little abstraction
> goes a long way.
> 
>> From the documentation:
>> 
>> listen on interface [family] [options]
>> Listen on the interface for incoming connections, using the same
>> syntax as ifconfig(8). The interface parameter may also be an
>> interface group, an IP address, or a domain name. Listening can
>> optionally be restricted to a specific address family, which can be
>> either inet4 or inet6.
>> 
>> listen on socket [options]
>> Listen for incoming SMTP connections on the Unix domain socket
>> /var/run/smtpd.sock. This is done by default, even if the directive
>> is absent.
> 
> So you can either have an opensmtp-interface (with family and a bunch
> of options) or an opensmtp-socket (with a bunch of options). Sounds
> like a much nicer ontology, doesn't it?

That does make much more sense!  I'll do that.

> 
>>> [...]
>> 
>> Too much to check, too little time. Maybe return later.
>> 

To summarize the updated tasks that you have given me are:
 
 1) Write a proper changelog.
 2) define "string-in-list?" with member?
 Are there other procedures that could use this?
 3) DONE replace [] with ()
 4) Shorten the sanitize procedure for opensmtpd-option-configuration
 5) Review your class names.

I also don't think it makes too much sense to add -configuration for
anything but the top-level configuration record, it just requires you
to type much more configuration than you probably want.

Also does guix have a style guide for writing services?  Do we usually
only put "-configuration" for the top level configuration?  Is
that the current style recommendations?
 
eg: rename opensmtpd-listen-on-configuration and
opensmtpd-listen-on-socket-configuration to opensmtpd-interface
 and opensmtpd-socket.




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2
  2022-07-07 17:27     ` jbranso--- via Guix-patches via
@ 2022-07-07 18:20       ` Liliana Marie Prikler
  2022-07-08  3:06         ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
  0 siblings, 1 reply; 23+ messages in thread
From: Liliana Marie Prikler @ 2022-07-07 18:20 UTC (permalink / raw)
  To: jbranso, 56046

Am Donnerstag, dem 07.07.2022 um 17:27 +0000 schrieb
jbranso@dismail.de:
> Also does guix have a style guide for writing services?  Do we
> usually only put "-configuration" for the top level configuration? 
> Is that the current style recommendations?
Style guide #0 is "look at what already exists".  For example, the
jami-service also defines jami-account via define-configuration.  Hope
that helps.

Cheers




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration.
  2022-07-07 18:20       ` Liliana Marie Prikler
@ 2022-07-08  3:06         ` Joshua Branson via Guix-patches via
  2022-07-12 15:45           ` Joshua Branson via Guix-patches via
  0 siblings, 1 reply; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-07-08  3:06 UTC (permalink / raw)
  To: Liliana Marie Prikler; +Cc: 56046

Liliana Marie Prikler <liliana.prikler@gmail.com> writes:

> Am Donnerstag, dem 07.07.2022 um 17:27 +0000 schrieb
> jbranso@dismail.de:
>> Also does guix have a style guide for writing services?  Do we
>> usually only put "-configuration" for the top level configuration? 
>> Is that the current style recommendations?
> Style guide #0 is "look at what already exists".  For example, the
> jami-service also defines jami-account via define-configuration.  Hope
> that helps.
>

I suppose that I was following the nginx style.  It seems like most of
their records end in "-configuration".  Thanks again for reviewing this.
I should have an updated patch soon.

>
> Cheers




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration.
  2022-07-08  3:06         ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
@ 2022-07-12 15:45           ` Joshua Branson via Guix-patches via
  2022-07-12 16:38             ` Joshua Branson via Guix-patches via
  0 siblings, 1 reply; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-07-12 15:45 UTC (permalink / raw)
  To: Liliana Marie Prikler; +Cc: 56046

Joshua Branson <jbranso@dismail.de> writes:

Just an update on progress.  The main thing to report is that the best
place to find the task list is here:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd.org


The best place to find a good example configuration will always be found
here:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd.org#example-configuration


The main thing that I am focusing on now is how to make it easy for
users of this service to use opensmtpd filters:

search for "enable to do dkimsigning or bogofilter" is the file and
you'll see where it is.  for some reason the link is REALLY long when I
try to paste it in this email.


Thanks,

Joshua




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration.
  2022-07-12 15:45           ` Joshua Branson via Guix-patches via
@ 2022-07-12 16:38             ` Joshua Branson via Guix-patches via
  0 siblings, 0 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-07-12 16:38 UTC (permalink / raw)
  To: Liliana Marie Prikler; +Cc: 56046

Joshua Branson <jbranso@dismail.de> writes:

Video update!

https://video.hardlimit.com/w/p/bmbYAkQ84BBfF4aAZNAPcR?playlistPosition=15&resume=true

That's a link to a video update of why
opensmtpd-filter-configuration-proc should be a string or list of
strings and/or gexps instead of just being a mixed-text-file.

It is primarily meant for nckx on irc.  But anyone else is free to
comment. 


Thanks,

Joshua




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [Patch master v2] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
                   ` (2 preceding siblings ...)
  2022-07-05 21:36 ` jbranso--- via Guix-patches via
@ 2022-10-24 17:30 ` Joshua Branson via Guix-patches via
  2022-10-24 18:28   ` Liliana Marie Prikler
  2022-10-24 22:18   ` [bug#56046] [Patch master v2] " jbranso--- via Guix-patches via
  2022-12-23 16:39 ` [bug#56046] [PATCH opensmtpd-records v4 fixing charset=y error] " Joshua Branson via Guix-patches via
  2023-06-15 16:06 ` [bug#56046] [PATCH] services: mail: " Vivien Kraus via Guix-patches via
  5 siblings, 2 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-10-24 17:30 UTC (permalink / raw)
  To: 56046; +Cc: liliana.prikler, Joshua Branson

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 158662 bytes --]

This is a V2 patch.  I've added some tests that help test for various
ways that users could accidentally misconfigure their configuration.

I probably need to make those error messages, use   
(guix diagnostics).  Currently compiling the tests, auto runs them.
So "make" auto runs the tests.  Also their error messages are output
to the terminal, and I'm not sure how to turn that off.

tl;dr this is a WIP patch, and I just wanted to submit something,
because I keep finding more things that I need to fix.

The task list as always is here:
https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd.org  

Openmstpd-configuration may only be configured by a config-file that
uses the smtpd.conf syntax.  This patch, enables one to configure
opensmtpd by using record types.

* gnu/services/mail.scm:
(opensmtpd-table-configuration,
opensmtpd-ca-configuration,
opensmtpd-pki-configuration,
opensmtpd-action-local-delivery-configuration,
opensmtpd-maildir-configuration,
opensmtpd-mda-configuration,
opensmtpd-action-relay-configuration,
opensmtpd-option-configuration,
opensmtpd-filter-phase-configuration,
opensmtpd-filter-configuration,
opensmtpd-interface,
opensmtpd-socket,
opensmtpd-match-configuration,
opensmtpd-smtp-configuration,
opensmtpd-srs-configuration,
opensmtpd-queue-configuration, and
opensmtpd-configuration): New records.

(false?, is-value-right-type, add-comma-or-string,
list-of-procedures->string, string-in-list?, my-sanitize,
opensmtpd-filter-chain?, throw-error-duplicate-option,
sanitize-list-of-options-for-match-configuration, sanitize-filters,
list-has-duplicates-or-non-filters?,
filter-phase-has-message-and-value?,
filter-phase-decision-lacks-proper-message?,
filter-phase-lacks-proper-value?,
filter-phase-has-incorrect-junk-or-bypass?,
filter-phase-junks-after-commit?,
list-of-unique-filter-or-filter-phase?, throw-error,
contains-duplicate?, list-of-type?, list-of-strings?,
list-of-unique-opensmtpd-option-configuration?,
list-of-opensmtpd-ca-configuration?,
list-of-opensmtpd-pki-configuration?,
list-of-opensmtpd-listen-on-configuration?,
list-of-unique-opensmtpd-match-configuration?, list-of-strings->string,
assoc-list? assoc-list, variable->string,
table-whose-data-are-assoc-list?,
table-whose-data-are-a-list-of-strings?, assoc-list->string,
opensmtpd-table-configuration->string,
opensmtpd-listen-on-configuration->string,
opensmtpd-listen-on-socket-configuration->string,
opensmtpd-action-relay-configuration->string,
opensmtpd-lmtp-configuration->string,
opensmtpd-mda-configuration->string,
opensmtpd-maildir-configuration->string,
opensmtpd-action-local-delivery-configuration->string,
opensmtpd-action->string, opensmtpd-option-configuration->string,
opensmtpd-match-configuration->string,
opensmtpd-ca-configuration->string, opensmtpd-pki-configuration->string,
generate-filter-chain-name, opensmtpd-filter-chain->string,
opensmtpd-filter-phase-configuration->string, opensmtpd-filters->string,
opensmtpd-configuration-listen->string,
opensmtpd-configuration-srs->string,
opensmtpd-smtp-configuration->string,
opensmtpd-configuration-queue->string, get-opensmtpd-actions,
get-opensmtpd-pki-configurations, get-opensmtpd-filters, flatten,
get-opensmtpd-tables, opensmtpd-configuration-fieldname->string,
list-of-records->string, opensmtpd-configuration->mixed-text-file): New
procedures.

* gnu/tests/mail.scm : new tests for various opensmtpd records.

* doc/guix.texi (OpenSMTPD Service): Added documentation for the
new records for opensmtpd.
---
 doc/guix.texi         | 1054 ++++++++++++++++++++-
 gnu/services/mail.scm | 2085 ++++++++++++++++++++++++++++++++++++++++-
 gnu/tests/mail.scm    |  355 +++++++
 3 files changed, 3475 insertions(+), 19 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 535c8cdfc3..c80f3e9d76 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -25409,14 +25409,59 @@ could instantiate a dovecot service like this:
 @subsubheading OpenSMTPD Service
 
 @deffn {Scheme Variable} opensmtpd-service-type
-This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
-service, whose value should be an @code{opensmtpd-configuration} object
-as in this example:
-
-@lisp
-(service opensmtpd-service-type
-         (opensmtpd-configuration
-           (config-file (local-file "./my-smtpd.conf"))))
+OpenSMTPD is an easy-to-use mail transfer agent (MTA). Its configuration file is
+throughly documented in @code{man 5 smtpd.conf}. OpenSMTPD @strong{listens} for incoming
+mail and @strong{matches} the mail to @strong{actions}. The following records represent those
+stages:
+
+@multitable {aaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @strong{listens}
+@tab @code{<opensmtpd-interface>}
+@item
+@tab @code{<opensmtpd-socket>}
+@item
+@tab
+@item @strong{matches}
+@tab @code{<opensmtpd-match>}
+@item
+@tab
+@item @strong{actions}
+@tab @code{<opensmtpd-local-delivery>}
+@item
+@tab @code{<opensmtpd-relay>}
+@end multitable
+
+Additionally, each @code{<opensmtpd-interface>} and
+@code{<opensmtpd-socket>} may use a list of
+@code{<opensmtpd-filter>}, and/or
+@code{<opensmtpd-filter-phase>} records to filter email/spam. Also
+numerous records' fieldnames use @code{<opensmtpd-table>} to hold lists
+or key value pairs of data.
+
+A simple example configuration is below:
+
+@lisp
+(let ((smtp.gnu.org (opensmtpd-pki
+                        (domain "smtp.gnu.org")
+                        (cert "file.cert")
+                        (key "file.key"))))
+  (service opensmtpd-service-type
+           (opensmtpd-configuration
+            (listen-ons (list
+                         (opensmtpd-interface
+                          (pki smtp.gnu.org))
+                         (opensmtpd-interface
+                          (pki smtp.gnu.org)
+                          (secure-connection "smtps"))))
+            (matches (list
+                      (opensmtpd-match
+                       (action
+                        (opensmtpd-local-delivery
+                         (name "local-delivery"))))
+                      (opensmtpd-match
+                       (action
+                        (opensmtpd-relay
+                         (name "relay")))))))))
 @end lisp
 @end deffn
 
@@ -25433,14 +25478,1007 @@ it listens on the loopback network interface, and allows for mail from
 users and daemons on the local machine, as well as permitting email to
 remote servers.  Run @command{man smtpd.conf} for more information.
 
+<<<<<<< HEAD
+@item @code{bounce} (default: @code{(list "4h")})
+
+@code{bounce} is a list of strings, which send warning messages to the envelope
+sender when temporary delivery failures cause a message to remain in the
+queue for longer than string delay. Each string delay parameter consists
+of a string beginning with a positive decimal integer and a unit 's', 'm', 'h',
+or 'd'. At most four delay parameters can be specified.
+
+@item @code{listen-ons} (default: @code{(list (opensmtpd-interface))})
+
+@code{listen-ons} is a list of @code{<opensmtpd-interface>} records.
+This list details what interfaces and ports OpenSMTPD listens on as well as
+other information.
+
+@item @code{listen-on-socket} (default: @code{(opensmtpd-socket)})
+
+Listens for incoming connections on the Unix domain socket.
+
+@item @code{includes} (default: @code{#f})
+
+@code{includes} is a list of string filenames. Each filename's contents is
+additional configuration that is inserted into the top of the configuration
+file.
+
+@item @code{matches} default:
+
+@lisp
+    (list (opensmtpd-match
+           (action (opensmtpd-local-delivery
+                    (name "local")
+                    (method "mbox")))
+           (for (opensmtpd-option
+                 (option "for local"))))
+          (opensmtpd-match
+           (action (opensmtpd-relay
+                    (name "outbound")))
+           (from (opensmtpd-option
+                  (option "from local")))
+           (for (opensmtpd-option
+                 (option "for any")))))
+@end lisp
+
+@code{matches} is a list of @code{<opensmtpd-match>} records, which
+matches incoming mail and sends it to a correspending action. The match
+records are evaluated sequentially, with the first match winning. If an
+incoming mail does not match any match records, then it is rejected.
+@c put this backin? @end itemize
+
+@c put this back in? @itemize
+@item @code{mta-max-deferred} (default: @code{100})
+
+When delivery to a given host is suspended due to temporary failures, cache
+at most number envelopes for that host such that they can be delivered as
+soon as another delivery succeeds to that host. The default is 100.
+
+@item @code{queue} (default: @code{#f})
+
+@code{queue} expects an @code{<opensmtpd-queue>} record. With it, one may
+compress and encrypt queue-ed emails as well as set the default expiration
+time for temporarily undeliverable messages.
+
+@item @code{smtp} (default: @code{#f})
+
+@code{smtp} expects an @code{<opensmtpd-smtp>} record, which lets one
+specifiy how large email may be along with other settings.
+
+@item @code{srs} (default: @code{#f})
+
+@code{srs} expects an @code{<opensmtpd-srs>} record, which lets one set
+up SRS, the Sender Rewritting Scheme.
+=======
 @item @code{setgid-commands?} (default: @code{#t})
 Make the following commands setgid to @code{smtpq} so they can be
 executed: @command{smtpctl}, @command{sendmail}, @command{send-mail},
 @command{makemap}, @command{mailq}, and @command{newaliases}.
 @xref{Setuid Programs}, for more information on setgid programs.
+>>>>>>> origin/master
 @end table
 @end deftp
 
+@itemize
+@item
+Data Type: opensmtpd-interface
+
+Data type representing the configuration of an
+@code{<opensmtpd-interface>}. Listen on the fieldname @code{interface} for
+incoming connections, using the same syntax as for ifconfig(8). The interface
+parameter may also be an string interface group, an string IP address, or a
+string domain name. Listening can optionally be restricted to a specific
+address fieldname @code{family}, which can be either ``inet4'' or ``inet6''.
+
+@itemize
+@item @code{interface} (default: ``lo'')
+
+The string interface to listen for incoming connections. These interface can
+usually be found by the command @code{ip link}.
+
+@item @code{family} (default: @code{#f})
+
+The string IP family to use.  Valid strings are ``inet4'' or ``inet6''.
+
+@item @code{auth} (default: @code{#f})
+
+Support SMTPAUTH: clients may only start SMTP transactions after successful
+authentication. If @code{auth} is @code{#t}, then users are authenticated against
+their own normal login credentials. Alternatively @code{auth} may be an
+@code{<opensmtpd-table>} whose users are authenticated against
+their passwords.
+
+@item @code{auth-optional} (default: @code{#f})
+
+Support SMTPAUTH optionally: clients need not authenticate, but may do so.
+This allows the @code{<opensmtpd-interface>} to both accept
+incoming mail from untrusted senders and permit outgoing mail from
+authenticated users (using @code{<opensmtpd-match>} fieldname
+@code{auth}). It can be used in situations where it is not possible to listen on
+a separate port (usually the submission port, 587) for users to
+authenticate.
+
+@item @code{filters} (default: @code{#f})
+
+A list of one or many @code{<opensmtpd-filter>} or
+@code{<opensmtpd-filter-phase>} records. The filters are applied
+sequentially. These records listen and filter on connections handled by this
+listener.
+
+@item @code{hostname} (default: @code{#f})
+
+Use string ``hostname'' in the greeting banner instead of the default server
+name.
+
+@item @code{hostnames} (default: @code{#f})
+
+Override the server name for specific addresses. Use a
+@code{<opensmtpd-table>} containing a mapping of string IP
+addresses to hostnames. If the address on which the connection arrives
+appears in the mapping, the associated hostname is used.
+
+@item @code{mask-src} (default: @code{#f})
+
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{disable-dsn} (default: @code{#f})
+
+When @code{#t}, then disable the DSN (Delivery Status Notification) extension.
+
+@item @code{pki} (default: @code{#f})
+
+For secure connections, use an @code{<opensmtpd-pki>}
+to prove a mail server's identity.
+
+@item @code{port} (default: @code{#f})
+
+Listen on the integer port instead of the default port of 25.
+
+@item @code{proxy-v2} (default: @code{#f})
+
+If @code{#t}, then support the PROXYv2 protocol, rewriting appropriately source
+address received from proxy.
+
+@item @code{received-auth} (default: @code{#f})
+
+If @code{#t}, then in “Received” headers, report whether the session was
+authenticated and by which local user.
+
+@item @code{senders} (default: @code{#f})
+
+Look up the authenticated user in the supplied
+@code{<opensmtpd-table>} to find the email addresses that user is
+allowed to submit mail as.
+
+@item @code{secure-connection} (default: @code{#f})
+
+This is a string of one of these options:
+
+@multitable {aaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``smtps''
+@tab Support SMTPS, by default on port 465.
+@item ``tls''
+@tab Support STARTTLS, by default on port 25.
+@item ``tls-require-verify''
+@tab Like tls, but force clients to establish
+@item
+@tab a secure connection before being allowed to
+@item
+@tab start an SMTP transaction.  With the verify
+@item
+@tab option, clients must also provide a valid
+@item
+@tab certificate to establish an SMTP session.
+@end multitable
+
+@item @code{tag} (default: @code{#f})
+
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-socket
+
+Data type representing the configuration of an
+@code{<opensmtpd-socket>}. Listen for incoming SMTP
+connections on the Unix domain socket @samp{/var/run/smtpd.sock}. This is done by
+default, even if the directive is absent.
+
+@itemize
+@item @code{filters} (default: @code{#f})
+
+A list of one or many @code{<opensmtpd-filter>} or
+@code{<opensmtpd-filter-phase>} records. These filter incoming
+connections handled by this listener.
+
+@item @code{mask-src} (default: @code{#f})
+
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{tag} (default: @code{#f})
+
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-match
+
+This data type represents the configuration of an
+@code{<opensmtpd-match>} record.
+
+If at least one mail envelope matches the options of one match record, receive
+the incoming message, put a copy into each matching envelope, and atomically
+save the envelopes to the mail spool for later processing by the respective
+@code{<opensmtpd-action>} found in fieldname @code{action}.
+
+@itemize
+@item @code{action} (default: @code{#f})
+
+If mail matches this match configuration, then do this action. Valid values
+include @code{<opensmtpd-local-delivery>} or
+@code{<opensmtpd-relay>}.
+
+@item @code{options} (default: @code{#f}) @code{<opensmtpd-option>}
+The fieldname 'option' is a list of unique
+@code{<opensmtpd-option>} records.
+
+Each @code{<opensmtpd-option>} record's fieldname 'option' has some
+mutually exclusive options: there can be only one ``for'' and only one ``from'' option.
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@headitem for
+@tab from
+@item only use one of the following:
+@tab only use one of the following:
+@item ``for any''
+@tab ``from any''
+@item ``for local''
+@tab ``from auth''
+@item ``for domain''
+@tab ``from local''
+@item ``for rcpt-to''
+@tab ``from mail-from''
+@item
+@tab ``from socket''
+@item
+@tab ``from src''
+@end multitable
+
+The following matching options are supported and can all be negated (via not
+#t). The options that support a table (anything surrounded with '<' and '>'
+eg: <table>), also support specifying regex via (regex #t).
+
+@itemize
+@item @samp{for any}
+
+Specify that session may address any destination.
+
+@item @samp{for local}
+
+Specify that session may address any local domain.  This is the default,
+and may be omitted.
+
+@item @samp{for domain _domain_ | <domain>}
+
+Specify that session may address the string or list table domain.
+
+@item @samp{for rcpt-to _recipient_ | <recipient>}
+
+Specify that session may address the string or list table recipient.
+
+@item @samp{from any}
+
+Specify that session may originate from any source.
+
+@item @samp{from auth}
+
+Specify that session may originate from any authenticated user, no matter
+the source IP address.
+
+@item @samp{from auth _user_ | <user>}
+
+Specify that session may originate from authenticated user or user list
+user, no matter the source IP address.
+
+@item @samp{from local}
+
+Specify that session may only originate from a local IP address, or from
+the local enqueuer.  This is the default, and may be omitted.
+
+@item @samp{from mail-from _sender_ | <sender>}
+
+Specify that session may originate from sender or table sender, no
+matter the source IP address.
+
+@item @samp{from rdns}
+
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS@.
+
+@item @samp{from rdns _hostname_ | <hostname>}
+
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS matching string or list string hostname.
+
+@item @samp{from socket}
+
+Specify that session may only originate from the local enqueuer.
+
+@item @samp{from src _address_ | <address>}
+
+Specify that session may only originate from string or list table address
+which can be a specific address or a subnet expressed in CIDR-notation.
+
+@item @samp{auth}
+
+Matches transactions which have been authenticated.
+
+@item @samp{auth _username_ | <username>}
+
+Matches transactions which have been authenticated for user or user list
+username.
+
+@item @samp{helo _helo-name_ | <helo-name>}
+
+Specify that session's HELO / EHLO should match the string or list table
+helo-name.
+
+@item @samp{mail-from _sender_ | <sender>}
+
+Specify that transactions's MAIL FROM should match the string or list
+table sender.
+
+@item @samp{rcpt-to _recipient_ | <recipient>}
+
+Specify that transaction's RCPT TO should match the string or list table
+recipient.
+
+@item @samp{tag tag}
+Matches transactions tagged with the given tag.
+
+@item @samp{tls}
+Specify that transaction should take place in a TLS channel.
+@end itemize
+
+Here is a simple example:
+@lisp
+    (opensmtpd-option
+     (not #t)
+     (regex #f)
+     (option "for domain")
+     (data (opensmtpd-table
+            (name "domain-table")
+            (data (list "gnu.org" "dismail.de")))))
+@end lisp
+
+The mail must NOT come from the domains @samp{gnu.org} or @samp{dismail.de}.
+
+@item Data Type: opensmtpd-option
+@end itemize
+
+@item Data Type: opensmtpd-local-delivery
+
+This data type represents the configuration of an
+@code{<opensmtpd-local-delivery>} record.
+
+@itemize
+@item
+@code{name} (default: @code{#f})
+
+@code{name} is the string name of the relay action.
+
+@item @code{method} (default: @code{"mbox"})
+
+The email delivery option.  Valid options are:
+
+@itemize
+@item @code{"mbox"}
+
+Deliver the message to the user's mbox with mail.local(8).
+
+@item @code{"expand-only"}
+
+Only accept the message if a delivery method was specified in an aliases
+or .forward file.
+
+@item @code{"forward-only"}
+
+Only accept the message if the recipient results in a remote address after
+the processing of aliases or forward file.
+
+@item @code{<opensmtpd-lmtp>}
+
+Deliver the message to an LMTP server at
+@code{<opensmtpd-lmtp>}'s fieldname @code{destination}. The location
+may be expressed as string host:port or as a UNIX socket. Optionally,
+@code{<opensmtpd-lmtponfiguration>}'s fieldname @code{rcpt-to} might be specified
+to use the recipient email address (after expansion) instead of the local
+user in the LMTP session as RCPT TO@.
+
+@item @code{<opensmtpd-maildir>}
+
+Deliver the message to the maildir in
+@code{<opensmtpd-maildir>}'s fieldname @code{pathname} if specified,
+or by default to @samp{~/Maildir}.
+
+The pathname may contain format specifiers that are expanded before use
+(see the below section about Format Specifiers).
+
+If @code{<opensmtpd-maildir>}'s record fieldname @code{junk} is @code{#t},
+then message will be moved to the ‘Junk’ folder if it contains a positive
+‘X-Spam’ header. This folder will be created under fieldname @code{pathname} if
+it does not yet exist.
+
+@item @code{<opensmtpd-mda>}
+
+Delegate the delivery to the @code{<opensmtpd-mda>}'s fieldname
+@code{command} (type string) that receives the message on its standard input.
+
+The @code{command} may contain format specifiers that are expanded before use
+(see Format Specifiers).
+@end itemize
+
+@item @code{alias} (default: @code{#f})
+
+Use the mapping table for aliases expansion. @code{alias} is an
+@code{<opensmtpd-table>}.
+
+@item @code{ttl} (default: @code{#f})
+
+@code{ttl} is a string specify how long a message may remain in the queue.  It's
+format is @samp{n@{s|m|h|d@}}.  eg: ``4m'' is four minutes.
+
+@item @code{user} (default: @code{#f} )
+
+@code{user} is the string username for performing the delivery, to be looked up
+with getpwnam(3).
+
+This is used for virtual hosting where a single username is in charge of
+handling delivery for all virtual users.
+
+This option is not usable with the mbox delivery method.
+
+@item @code{userbase} (default: @code{#f})
+
+@code{userbase} is an @code{<opensmtpd-table>} record for mapping user
+lookups instead of the getpwnam(3) function.
+
+The fieldnames @code{user} and @code{userbase} are mutually exclusive.
+
+@item @code{virtual} (default: @code{#f})
+
+@code{virtual} is an @code{<opensmtpd-table>} record is used for virtual
+expansion.
+@end itemize
+
+@item Data Type: opensmtpd-relay
+
+This data type represents the configuration of an
+@code{<opensmtpd-relay>} record.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+@code{name} is the string name of the relay action.
+
+@item @code{backup} (default: @code{#f})
+
+When @code{#t}, operate as a backup mail exchanger delivering messages to any
+mail exchanger with higher priority.
+
+@item @code{backup-mx} (default: @code{#f})
+
+Operate as a backup mail exchanger delivering messages to any mail exchanger
+with higher priority than mail exchanger identified as string name.
+
+@item @code{helo} (default: @code{#f})
+
+Advertise string heloname as the hostname to other mail exchangers during
+the HELO phase.
+
+@item @code{helo-src} (default: @code{#f} )
+
+ Use the mapping @code{<opensmtpd-table>} to look up a hostname
+matching the source address, to advertise during the HELO phase.
+
+@item @code{domain} (default: @code{#f})
+
+Do not perform MX lookups but look up destination domain in an
+@code{<opensmtpd-table>} and use matching relay url as relay host.
+
+@item @code{host} (default: @code{#f})
+
+Do not perform MX lookups but relay messages to the relay host described by
+the string relay-url. The format for relay-url is
+@samp{[proto://[label@@]]host[:port]}. The following protocols are available:
+
+@multitable {aaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item smtp
+@tab Normal SMTP session with opportunistic STARTTLS (the default).
+@item smtp+tls
+@tab Normal SMTP session with mandatory STARTTLS@.
+@item smtp+notls
+@tab Plain text SMTP session without TLS@.
+@item lmtp
+@tab LMTP session.  port is required.
+@item smtps
+@tab SMTP session with forced TLS on connection, default port is
+@item
+@tab 465.
+@end multitable
+
+Unless noted, port defaults to 25.
+
+The label corresponds to an entry in a credentials table, as documented in
+@samp{table(5)}. It is used with the @samp{"smtp+tls"} and @samp{"smtps"} protocols for
+authentication. Server certificates for those protocols are verified by
+default.
+
+@item @code{pki} (default: @code{#f})
+
+For secure connections, use the certificate associated with
+@code{<opensmtpd-pki>} (declared in a pki directive) to prove the
+client's identity to the remote mail server.
+
+@item @code{srs} (default: @code{#f})
+
+If @code{#t}, then when relaying a mail resulting from a forward, use the Sender
+Rewriting Scheme to rewrite sender address.
+
+@item @code{tls} (default: @code{#f}) boolean or string ``no-verify''
+
+When @code{#t}, Require TLS to be used when relaying, using mandatory STARTTLS by
+default. When used with a smarthost, the protocol must not be
+@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not require a valid
+certificate.
+
+@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table>}
+
+Use the alist @code{<opensmtpd-table>} for connecting to relay-url
+using credentials. This option is usable only with fieldname @code{host} option.
+
+@item @code{mail-from} (default: @code{#f}) string
+
+Use the string mailaddress as MAIL FROM address within the SMTP transaction.
+
+@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-table>}
+
+Use the string or @code{<opensmtpd-table>} sourceaddr for the
+source IP address, which is useful on machines with multiple interfaces. If
+the list contains more than one address, all of them are used in such a way
+that traffic is routed as efficiently as possible.
+@end itemize
+
+@item Data Type: opensmtpd-filter
+
+This data type represents the configuration of an
+@code{<opensmtpd-filter>}. This is the filter record one should use
+if they want to use an external package to filter email eg: rspamd or
+spamassassin.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+The string name of the filter.
+
+@item @code{proc} (default: @code{#f})
+
+The string command or process name.  If @code{proc-exec} is @code{#t}, @code{proc} is
+treated as a command to execute.  Otherwise, it is a process name.
+
+@item @code{proc-exec} (default: @code{#f})
+@end itemize
+
+@item Data Type: opensmtpd-filter-phase
+
+This data type represents the configuration of an
+@code{<opensmtpd-filter-phase>}.
+
+In a regular workflow, smtpd(8) may accept or reject a message based only on
+the content of envelopes. Its decisions are about the handling of the message,
+not about the handling of an active session.
+
+Filtering extends the decision making process by allowing smtpd(8) to stop at
+each phase of an SMTP session, check that options are met, then decide if a
+session is allowed to move forward.
+
+With filtering via an @code{<opensmtpd-filter-phase>} record, a
+session may be interrupted at any phase before an envelope is complete. A
+message may also be rejected after being submitted, regardless of whether the
+envelope was accepted or not.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+The string name of the filter phase.
+
+@item @code{phase-name} (default: @code{#f})
+
+The string name of the phase. Valid values are:
+
+@multitable {aaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``connect''
+@tab upon connection, before a banner is displayed
+@item ``helo''
+@tab after HELO command is submitted
+@item ``ehlo''
+@tab after EHLO command is submitted
+@item ``mail-from''
+@tab after MAIL FROM command is submitted
+@item ``rcpt-to''
+@tab after RCPT TO command is submitted
+@item ``data''
+@tab after DATA command is submitted
+@item ``commit''
+@tab after message is fully is submitted
+@end multitable
+
+@item @code{options} (default @code{#f})
+
+A list of unique @code{<opensmtpd-option>} records.
+
+At each phase, various options, specified by a list of
+@code{<opensmtpd-option>}, may be checked. The
+@code{<opensmtpd-option>}'s fieldname 'option' values of: ``fcrdns'',
+``rdns'', and ``src'' data are available in all phases, but other data must have
+been already submitted before they are available. Options with a @samp{<table>}
+next to them require the @code{<opensmtpd-option>}'s fieldname
+@code{data} to be an @code{<opensmtpd-table>}. There are the available
+options:
+
+@multitable {aaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item fcrdns
+@tab forward-confirmed reverse DNS is valid
+@item rdns
+@tab session has a reverse DNS
+@item rdns <table>
+@tab session has a reverse DNS in table
+@item src <table>
+@tab source address is in table
+@item helo <table>
+@tab helo name is in table
+@item auth
+@tab session is authenticated
+@item auth <table>
+@tab session username is in table
+@item mail-from <table>
+@tab sender address is in table
+@item rcpt-to <table>
+@tab recipient address is in table
+@end multitable
+
+These conditions may all be negated by setting
+@code{<opensmtpd-option>}'s fieldname @code{not} to @code{#t}.
+
+Any conditions that require a table may indicate that tables include regexs
+setting @code{<opensmtpd-option>}'s fieldname @code{regex} to @code{#t}.
+
+@item @code{decision}
+
+A string decision to be taken. Some decisions require an @code{message} or
+@code{value}. Valid strings are:
+
+@multitable {aaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``bypass''
+@tab the session or transaction bypasses filters
+@item ``disconnect'' message
+@tab the session is disconnected with message
+@item ``junk''
+@tab the session or transaction is junked, i.e., an
+@item
+@tab ‘X-Spam: yes’ header is added to any messages
+@item ``reject'' message
+@tab the command is rejected with message
+@item ``rewrite'' value
+@tab the command parameter is rewritten with value
+@end multitable
+
+Decisions that involve a message require that the message be RFC valid,
+meaning that they should either start with a 4xx or 5xx status code.
+Descisions can be taken at any phase, though junking can only happen before
+a message is committed.
+
+@item @code{message} (default @code{#f})
+
+A string message beginning with a 4xx or 5xx status code.
+
+@item @code{value} (default: @code{#f})
+
+A number value.  @code{value} and @code{message} are mutually exclusive.
+@end itemize
+
+@item Data Type: opensmtpd-option
+
+This data type represents the configuration of an
+@code{<opensmtpd-option>}, which is used by
+@code{<opensmtpd-filter-phase>} and @code{<opensmtpd-match>}
+to match various options for email.
+
+@itemize
+@item @code{conditition} (default @code{#f})
+
+A string option to be taken. Some options require a string or an
+@code{<opensmtpd-table>} via the fieldname data. When the option
+record is used inside of an @code{<opensmtpd-filter-phase>}, then
+valid strings are:
+
+At each phase, various options may be matched. The fcrdns, rdns, and src
+data are available in all phases, but other data must have been already
+submitted before they are available.
+
+@multitable {aaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item ``fcrdns''
+@tab forward-confirmed reverse DNS is valid
+@item ``rdns''
+@tab session has a reverse DNS
+@item ``rdns'' <table>
+@tab session has a reverse DNS in table
+@item ``src'' <table>
+@tab source address is in table
+@item ``helo'' <table>
+@tab helo name is in table
+@item ``auth''
+@tab session is authenticated
+@item ``auth'' <table>
+@tab session username is in table
+@item ``mail-from'' <table>
+@tab sender address is in table
+@item ``rcpt-to'' <table>
+@tab recipient address is in table
+@end multitable
+
+When @code{<opensmtpd-option>} is used inside of an
+@code{<opensmtpd-match>}, then valid strigs for fieldname @code{option}
+are: ``for'', ``for any'', ``for local'', ``for domain'', ``for rcpt-to'', ``from any''
+``from auth'', ``from local'', ``from mail-from'', ``from rdns'', ``from socket'',
+``from src'', ``auth'', ``helo'', ``mail-from'', ``rcpt-to'', ``tag'', or ``tls''.
+
+@item @code{data} (default @code{#f}) @code{<opensmtpd-table>}
+
+Some options require a table to be present. One would specify that table
+here.
+@item @code{regex} (default: @code{#f}) boolean
+
+Any options using a table may indicate that tables hold regex by
+prefixing the table name with the keyword regex.
+
+@item @code{not} (default: @code{#f}) boolean
+
+When @code{#t}, this option record is negated.
+@end itemize
+
+@item Data Type: opensmtpd-table
+
+This data type represents the configuration of an
+@code{<opensmtpd-table>}.
+
+@itemize
+@item @code{name} (default @code{#f})
+
+@code{name} is the name of the @code{<opensmtpd-table>} record.
+
+@item @code{data} (default: @code{#f})
+
+@code{data} expects a list of strings or an alist, which is a list of
+cons cells.  eg: @code{(data (list ("james" . "password")))} OR
+@code{(data (list ("gnu.org" "fsf.org")))}.
+@end itemize
+
+@item Data Type: opensmtpd-pki
+
+This data type represents the configuration of an
+@code{<opensmtpd-pki>}.
+
+@itemize
+@item @code{domain} (default @code{#f})
+
+@code{domain} is the string name of the @code{<opensmtpd-pki>} record.
+
+@item @code{cert} (default: @code{#f})
+
+@code{cert} (default: @code{#f})
+
+@code{cert} is the string certificate filename to use for this pki.
+
+@item @code{key} (default: @code{#f})
+
+@code{key} is the string certificate falename to use for this pki.
+
+@item @code{dhe} (default: @code{"none"})
+
+Specify the DHE string parameter to use for DHE cipher suites with host
+pkiname. Valid parameter values are ``none'', ``legacy'', or ``auto''. For ``legacy'', a
+fixed key length of 1024 bits is used, whereas for ``auto'', the key length is
+determined automatically. The default is ``none'', which disables DHE cipher
+suites.
+@end itemize
+
+@item Data Type: opensmtpd-maildir
+
+@itemize
+@item @code{pathname} (default: @code{"~/Maildir"})
+
+Deliver the message to the maildir if pathname if specified, or by default
+to @samp{~/Maildir}.
+
+The pathname may contain format specifiers that are expanded before use
+(see FORMAT SPECIFIERS).
+
+@item @code{junk} (default: @code{#f})
+
+If the junk argument is @code{#t}, then the message will be moved to the @samp{‘Junk’}
+folder if it contains a positive @samp{‘X-Spam’} header. This folder will be
+created under pathname if it does not yet exist.
+@end itemize
+
+@item Data Type: opensmtpd-mda
+
+@itemize
+@item @code{name}
+
+The string name for this MDA command.
+
+@item @code{command}
+
+Delegate the delivery to a command that receives the message on its standard
+input.
+
+The command may contain format specifiers that are expanded before use (see
+FORMAT SPECIFIERS).
+@end itemize
+
+@item Data Type: opensmtpd-queue
+
+@itemize
+@item @code{compression} (default @code{#f})
+
+Store queue files in a compressed format. This may be useful to save disk
+space.
+
+@item @code{encryption} (default @code{#f})
+
+Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If no key is specified, it is
+read with getpass(3). If the string stdin or a single dash (‘-’) is given
+instead of a key, the key is read from the standard input.
+
+@item @code{ttl-delay} (default @code{#f})
+
+Set the default expiration time for temporarily undeliverable messages,
+given as a positive decimal integer followed by a unit s, m, h, or d. The
+default is four days (``4d'').
+@end itemize
+
+@item Data Type: opensmtpd-smtp
+
+Data type representing an @code{<opensmtpd-smtp>} record.
+
+@itemize
+@item @code{ciphers} (default: @code{#f})
+
+Set the control string for SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default is
+         ``HIGH:!aNULL:!MD5''.
+
+@item @code{limit-max-mails} (default: @code{100})
+
+Limit the number of messages to count for each sessio
+
+@item @code{limit-max-rcpt} (default: @code{1000})
+
+Limit the number of recipients to count for each transaction.
+
+@item @code{max-message-size} (default: @code{35M})
+
+Reject messages larger than size, given as a positive number of bytes or as
+a string to be parsed with scan@math{_scaled}(3).
+
+@item @code{sub-addr-delim character} (default: @code{+})
+
+When resolving the local part of a local email address, ignore the ASCII
+character and all characters following it. This is helpful for email
+filters. @samp{"admin+bills@@gnu.org"} is the same email address as
+@samp{"admin@@gnu.org"}. BUT an email filter can filter emails addressed to first
+email address into a 'Bills' email folder.
+@end itemize
+
+@item Data Type: opensmtpd-srs
+
+@itemize
+@item @code{key} (default: @code{#f})
+
+Set the secret key to use for SRS, the Sender Rewriting Scheme.
+
+@item @code{backup-key} (default: @code{#f})
+
+Set a backup secret key to use as a fallback for SRS@. This can be used to
+implement SRS key rotation.
+
+@item @code{ttl-delay} (default: @code{"4d"})
+
+Set the time-to-live delay for SRS envelopes. After this delay, a bounce
+reply to the SRS address will be discarded to limit risks of forged
+addresses.
+@end itemize
+
+@item Format Specifiers
+
+Some configuration records support expansion of their parameters at
+runtime. Such records (for example
+@code{<opensmtpd-maildir>}, @code{<opensmtpd-mda>}) may use
+format specifiers which are expanded before delivery or relaying. The
+following formats are currently supported:
+
+@multitable {aaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{sender@}}
+@tab sender email address, may be empty string
+@item @samp{%@{sender.user@}}
+@tab user part of the sender email address, may be empty
+@item @samp{%@{sender.domain@}}
+@tab domain part of the sender email address, may be empty
+@item @samp{%@{rcpt@}}
+@tab recipient email address
+@item @samp{%@{rcpt.user@}}
+@tab user part of the recipient email address
+@item @samp{%@{rcpt.domain@}}
+@tab domain part of the recipient email address
+@item @samp{%@{dest@}}
+@tab recipient email address after expansion
+@item @samp{%@{dest.user@}}
+@tab user part after expansion
+@item @samp{%@{dest.domain@}}
+@tab domain part after expansion
+@item @samp{%@{user.username@}}
+@tab local user
+@item @samp{%@{user.directory@}}
+@tab home directory of the local user
+@item @samp{%@{mbox.from@}}
+@tab name used in mbox From separator lines
+@item @samp{%@{mda@}}
+@tab mda command, only available for mda wrappers
+@end multitable
+
+Expansion formats also support partial expansion using the optional bracket notations
+with substring offset.  For example, with recipient domain @samp{“example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt.domain[0]@}}
+@tab expands to “e”
+@item @samp{%@{rcpt.domain[1]@}}
+@tab expands to “x”
+@item @samp{%@{rcpt.domain[8:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[-3:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[0:6]@}}
+@tab expands to “example”
+@item @samp{%@{rcpt.domain[0:-4]@}}
+@tab expands to “example”
+@end multitable
+
+In addition, modifiers may be applied to the token.  For example, with recipient
+@samp{“User+Tag@@Example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt:lowercase@}}
+@tab expands to “user+tag@@example.org”
+@item @samp{%@{rcpt:uppercase@}}
+@tab expands to “USER+TAG@@EXAMPLE.ORG”
+@item @samp{%@{rcpt:strip@}}
+@tab expands to “User@@Example.org”
+@item @samp{%@{rcpt:lowercasestrip@}}
+@tab expands to “user@@example.org”
+@end multitable
+
+For security concerns, expanded values are sanitized and potentially dangerous
+characters are replaced with ‘:’. In situations where they are desirable, the
+“raw” modifier may be applied. For example, with recipient
+@samp{“user+t?g@@example.org”}:
+
+@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt@}}
+@tab expands to “user+t:g@@example.org”
+@item @samp{%@{rcpt:raw@}}
+@tab expands to “user+t?g@@example.org”
+@end multitable
+@end itemize
+
 @subsubheading Exim Service
 
 @cindex mail transfer agent (MTA)
diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index 43f144a42d..d86e083d19 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -58,10 +58,146 @@ (define-module (gnu services mail)
             mailbox-configuration
             namespace-configuration
 
+            opensmtpd-table
+            opensmtpd-table?
+            opensmtpd-table-name
+            opensmtpd-table-file-db
+            opensmtpd-table-data
+
+            opensmtpd-ca
+            opensmtpd-ca?
+            opensmtpd-ca-name
+            opensmtpd-ca-file
+
+            opensmtpd-pki
+            opensmtpd-pki?
+            opensmtpd-pki-domain
+            opensmtpd-pki-cert
+            opensmtpd-pki-key
+            opensmtpd-pki-dhe
+
+            opensmtpd-local-delivery
+            opensmtpd-local-delivery?
+            opensmtpd-local-delivery-method
+            opensmtpd-local-delivery-alias
+            opensmtpd-local-delivery-ttl
+            opensmtpd-local-delivery-user
+            opensmtpd-local-delivery-userbase
+            opensmtpd-local-delivery-virtual
+            opensmtpd-local-delivery-wrapper
+
+            opensmtpd-maildir
+            opensmtpd-maildir?
+            opensmtpd-maildir-pathname
+            opensmtpd-maildir-junk
+
+            opensmtpd-mda
+            opensmtpd-mda-name
+            opensmtpd-mda-command
+
+            opensmtpd-lmtp
+            opensmtpd-lmtp-destination
+            opensmtpd-lmtp-rcpt
+
+            opensmtpd-relay
+            opensmtpd-relay?
+            opensmtpd-relay-backup
+            opensmtpd-relay-backup-mx
+            opensmtpd-relay-helo
+            opensmtpd-relay-domain
+            opensmtpd-relay-host
+            opensmtpd-relay-pki
+            opensmtpd-relay-srs
+            opensmtpd-relay-tls
+            opensmtpd-relay-auth
+            opensmtpd-relay-mail-from
+            opensmtpd-relay-src
+
+            opensmtpd-option
+            opensmtpd-option?
+            opensmtpd-option-option
+            opensmtpd-option-not
+            opensmtpd-option-regex
+            opensmtpd-option-data
+
+            opensmtpd-filter-phase
+            opensmtpd-filter-phase?
+            opensmtpd-filter-phase-name
+            opensmtpd-filter-phase-phase-name
+            opensmtpd-filter-phase-options
+            opensmtpd-filter-phase-decision
+            opensmtpd-filter-phase-message
+            opensmtpd-filter-phase-value
+
+            opensmtpd-filter
+            opensmtpd-filter?
+            opensmtpd-filter-name
+            opensmtpd-filter-proc
+
+            opensmtpd-interface
+            opensmtpd-interface?
+            opensmtpd-interface-interface
+            opensmtpd-interface-family
+            opensmtpd-interface-auth
+            opensmtpd-interface-auth-optional
+            opensmtpd-interface-filters
+            opensmtpd-interface-hostname
+            opensmtpd-interface-hostnames
+            opensmtpd-interface-mask-src
+            opensmtpd-interface-disable-dsn
+            opensmtpd-interface-pki
+            opensmtpd-interface-port
+            opensmtpd-interface-proxy-v2
+            opensmtpd-interface-received-auth
+            opensmtpd-interface-senders
+            opensmtpd-interface-secure-connection
+            opensmtpd-interface-tag
+
+            opensmtpd-socket
+            opensmtpd-socket?
+            opensmtpd-socket-filters
+            opensmtpd-socket-mask-src
+            opensmtpd-socket-tag
+
+            opensmtpd-match
+            opensmtpd-match?
+            opensmtpd-match-action
+            opensmtpd-match-options
+
+            opensmtpd-smtp
+            opensmtpd-smtp?
+            opensmtpd-smtp-ciphers
+            opensmtpd-smtp-limit-max-mails
+            opensmtpd-smtp-limit-max-rcpt
+            opensmtpd-smtp-max-message-size
+            opensmtpd-smtp-sub-addr-delim character
+
+            opensmtpd-srs
+            opensmtpd-srs?
+            opensmtpd-srs-key
+            opensmtpd-srs-backup-key
+            opensmtpd-srs-ttl-delay
+
+            opensmtpd-queue
+            opensmtpd-queue?
+            opensmtpd-queue-compression
+            opensmtpd-queue-encryption
+            opensmtpd-queue-ttl-delay
+
             opensmtpd-configuration
             opensmtpd-configuration?
-            opensmtpd-service-type
-            %default-opensmtpd-config-file
+            opensmtpd-package
+            opensmtpd-config-file
+            opensmtpd-configuration-bounce
+            opensmtpd-configuration-listen-ons
+            opensmtpd-configuration-listen-on-socket
+            opensmtpd-configuration-includes
+            opensmtpd-configuration-matches
+            opensmtpd-configuration-mda-wrappers
+            opensmtpd-configuration-mta-max-deferred
+            opensmtpd-configuration-srs
+            opensmtpd-configuration-smtp
+            opensmtpd-configuration-queue
 
             mail-aliases-service-type
 
@@ -1641,22 +1777,1942 @@ (define (generate-dovecot-documentation)
        (listeners unix-listener-configuration fifo-listener-configuration
                   inet-listener-configuration))
       (protocol-configuration ,protocol-configuration-fields))
-  'dovecot-configuration))
+   'dovecot-configuration))
 
 \f
 ;;;
 ;;; OpenSMTPD.
 ;;;
 
+;; file-exists? is in the guile standard library.  BUT I errors if its arg
+;; is a list.  eg:  (file-exists? (list "hello" "hello"))
+;; TODO I need to find a way to remove this definition and rewrite my code.
+(define (file-exists? file)
+  (if (string? file)
+      (access? file F_OK)
+      #f))
+
+;; some fieldnames have a default value of #f, which is ok.  They cannot have a value of #t.
+;; for example opensmtpd-table-data can be #f, BUT NOT true.
+;; my/sanitize procedure tests values to see if they are of the right kind.
+;; procedure false? is needed to allow fields like 'values' to be blank, (empty), or #f BUT also
+;; have a value like a list of strings.
+(define (false? var)
+  (eq? #f var))
+
+;; this procedure takes in a var and a list of procedures.  It loops through list of procedures passing in var to each.
+;; if one procedure returns #t, the function returns true.  Otherwise #f.
+;; TODO for fun rewrite this using map
+;; If I rewrote it in map, then it may help with sanitizing.
+;; eg: I could then potentially easily sanitize vars with lambda procedures.
+(define (is-value-right-type? var list-of-procedures record fieldname)
+  (if (null? list-of-procedures)
+      #f
+      (if ((car list-of-procedures) var)
+          #t
+          (is-value-right-type? var (cdr list-of-procedures) record fieldname))))
+
+;; converts strings like this:
+;; "apple, ham, cherry" -> "apple, ham, or cherry"
+;; "pineapple" -> "pinneapple".
+;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
+(define (add-comma-or string)
+  (define last-comma-location (string-rindex string #\,))
+  (if last-comma-location
+      (if (string-contains string ", or" last-comma-location)
+          string
+          (string-replace string ", or" last-comma-location
+                          (+ 1 last-comma-location)))
+      string))
+
+(define (list-of-procedures->string procedures)
+  (define string
+    (let loop ((procedures procedures))
+      (if (null? procedures)
+          ""
+          (begin
+            (string-append
+             (cond ((eq? false? (car procedures))
+                    "#f , ")
+                   ((eq? boolean? (car procedures))
+                    "boolean, ")
+                   ((eq? string? (car procedures))
+                    "string, ")
+                   ((eq? integer? (car procedures))
+                    "integer, ")
+                   ((eq? list-of-strings? (car procedures))
+                    "list of strings, ")
+                   ((eq? assoc-list? (car procedures))
+                    "an association list, ")
+                   ((eq? opensmtpd-pki? (car procedures))
+                    "an <opensmtpd-pki> record, ")
+                   ((eq? opensmtpd-table? (car procedures))
+                    "an <opensmtpd-table> record, ")
+                   ((eq? list-of-unique-opensmtpd-match? (car procedures))
+                    "a list of unique <opensmtpd-match> records, ")
+                   ((eq? list-of-strings-or-gexps? (car procedures))
+                    "a list of strings or gexps, ")
+                   ((eq? table-whose-data-are-assoc-list? (car procedures))
+                    (string-append
+                     "an <opensmtpd-table> record whose fieldname 'data' are an assoc-list \n"
+                     "(eg: (opensmtpd-table (name \"hostnames\") (data '((\"124.394.23.1\" . \"gnu.org\"))))), "))
+                   ((eq? file-exists? (car procedures))
+                    "file, ")
+                   (else "has an incorrect value, "))
+             (loop (cdr procedures)))))))
+  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
+
+(define (string-in-list? string list)
+  (member string list))
+
+(define (list-of-strings-or-gexps? list)
+  (and (list? list)
+       (cond ((null? list)
+              #t)
+             ((or (string? (car list))
+                  (gexp? (car list))
+                  (local-file? (car list))
+                  (file-append? (car list))
+                  (plain-file? (car list))
+                  (computed-file? (car list))
+                  (program-file? (car list)))
+              (list-of-strings-or-gexps? (cdr list)))
+             (else #f))))
+
+(define (my/sanitize var record fieldname list-of-procedures)
+  (if (is-value-right-type? var list-of-procedures record fieldname)
+      var
+      (begin
+        (display (string-append "<" record "> fieldname: '" fieldname "' is of type "
+                                (list-of-procedures->string list-of-procedures) "\n"))
+        (throw 'bad! var))))
+
+;; Some example opensmtpd-tables:
+;;
+;;  (opensmtpd-table (name "root accounts") (data '(("joshua" . "root@dismail.de") ("joshua" . "postmaster@dismail.de"))))
+;;  (opensmtpd-table (name "root accounts") (data (list "mysite.me" "your-site.com")))
+;;  TODO should <opensmtpd-table> support have a fieldname 'file'?
+;;  Or should I change name to name-or-file ?
+(define-record-type* <opensmtpd-table>
+  opensmtpd-table make-opensmtpd-table
+  opensmtpd-table?
+  this-record
+  (name opensmtpd-table-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table" "name" (list string?)))))
+  (file-db opensmtpd-table-file-db
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-table" "file-db"
+                                    (list boolean?)))))
+  ;; FIXME support an aliasing table as described here:
+  ;; https://man.openbsd.org/table.5
+  ;; One may have to use the record file for this.  I don't think tables support a table like this:
+  ;; table "name" { joshua = joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root = root@gnucode.me }
+  ;; If values is an absolute filename, then it will use said filename to house the table info.
+  ;; filename must be an absolute filename.
+  (data opensmtpd-table-data
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-table" "values"
+                                   (list list-of-strings? assoc-list? file-exists?)))))
+  ;; is a list of values or key values
+  ;; eg: (list "mysite.me" "your-site.com")
+  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" . "james@gnu.org"))
+  ;; I am currently making these values be as assocation list of strings only.
+  ;; FIXME should I allow a var like this?
+  ;; (list (cons "gnucode.me" 234.949.392.23))
+  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
+  ;; (opensmtpd-table-type record) returns the values' type.  The user SHOULD NEVER set the type.
+  ;; TODO jpoiret: on irc reccomends that I just use an outside function to determine fieldname 'values', type.
+  ;; it would be "simpler" and possibly easier for the next person working on this code to understand what is happening.
+  (type opensmtpd-table-type
+        (default #f)
+        (thunked)
+        (sanitize (lambda (var)
+                    (cond ((opensmtpd-table-data this-record)
+                           (if (list-of-strings? (opensmtpd-table-data this-record))
+                               (quote list-of-strings)
+                               (quote assoc-list)))
+                          ((file-exists? (opensmtpd-table-data this-record))
+                           (if (opensmtpd-table-file-db this-record)
+                               (quote db)
+                               (quote file)))
+                          (else
+                           (display "opensmtpd-table-type is broke\n")
+                           (throw 'bad! var)))))))
+
+(define-record-type* <opensmtpd-ca>
+  opensmtpd-ca make-opensmtpd-ca
+  opensmtpd-ca?
+  (name opensmtpd-ca-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca" "name" (list string?)))))
+  (file opensmtpd-ca-file
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca" "file" (list file-exists?))))))
+
+(define-record-type* <opensmtpd-pki>
+  opensmtpd-pki make-opensmtpd-pki
+  opensmtpd-pki?
+  (domain opensmtpd-pki-domain
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-pki" "domain" (list string?)))))
+  ;; TODO/FIXME this should probably be a list of files.  The opensmtpd documentation says
+  ;; that you could have a list of files:
+  ;;
+  ;; pki pkiname cert certfile
+  ;; Associate certificate file certfile with host pkiname, and use that file to prove
+  ;; the identity of the mail server to clients.  pkiname is the server's name, de‐
+  ;; rived from the default hostname or set using either
+  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/mailname or us‐
+  ;; ing the hostname directive.  If a fallback certificate or SNI is wanted, the ‘*’
+  ;; wildcard may be used as pkiname.
+
+  ;; A certificate chain may be created by appending one or many certificates, includ‐
+  ;; ing a Certificate Authority certificate, to certfile.  The creation of certifi‐
+  ;; cates is documented in starttls(8).
+  (cert opensmtpd-pki-cert
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-pki" "cert" (list file-exists?)))))
+  (key opensmtpd-pki-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-pki" "key" (list file-exists?)))))
+  ; todo sanitize this. valid parameters are "none", "legacy", or "auto".
+  (dhe opensmtpd-pki-dhe
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-dhe" "dhe" (list false? string?))))))
+
+(define-record-type* <opensmtpd-lmtp>
+  opensmtpd-lmtp make-opensmtpd-lmtp
+  opensmtpd-lmtp?
+  (destination opensmtpd-lmtp-destination
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-lmtp" "destination"
+                                        (list string?)))))
+  (rcpt-to opensmtpd-lmtp-rcpt-to
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-lmtp" "rcpt-to"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-mda>
+  opensmtpd-mda make-opensmtpd-mda
+  opensmtpd-mda?
+  (name opensmtpd-mda-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-mda" "name"
+                                 (list string?)))))
+  ;; TODO should I allow this command to be a gexp?
+  (command opensmtpd-mda-command
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-mda" "command"
+                                    (list string?))))))
+
+(define-record-type* <opensmtpd-maildir>
+  opensmtpd-maildir make-opensmtpd-maildir
+  opensmtpd-maildir?
+  (pathname opensmtpd-maildir-pathname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-maildir" "pathname"
+                                     (list false? string?)))))
+  (junk opensmtpd-maildir-junk
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-maildir" "junk"
+                                 (list boolean?))))))
+
+(define-record-type* <opensmtpd-local-delivery>
+  opensmtpd-local-delivery make-opensmtpd-local-delivery
+  opensmtpd-local-delivery?
+  (name opensmtpd-local-delivery-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-local-delivery" "name"
+                                 (list string?)))))
+  (method opensmtpd-local-delivery-method
+          (default "mbox")
+          (sanitize (lambda (var)
+                      (cond
+                       ((or (opensmtpd-lmtp? var)
+                            (opensmtpd-maildir? var)
+                            (opensmtpd-mda? var)
+                            (string=? var "mbox")
+                            (string=? var "expand-only")
+                            (string=? var "forward-only"))
+                        var)
+                       (else
+                        (begin
+                          (display (string-append "<opensmtpd-local-delivery> fieldname 'method' must be of type \n"
+                                                  "\"mbox\", \"expand-only\", \"forward-only\" \n"
+                                                  "<opensmtpd-lmtp>, <opensmtpd-maildir>, \n"
+                                                  "or <opensmtpd-mda>.\n"))
+                          (throw 'bad! var)))))))
+  (alias opensmtpd-local-delivery-alias
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-local-delivery" "alias"
+                                  (list false? opensmtpd-table?)))))
+  (ttl opensmtpd-local-delivery-ttl
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-local-delivery" "ttl"
+                                (list false? string?)))))
+  (user opensmtpd-local-delivery-user
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-local-delivery" "user"
+                                 (list false? string?)))))
+  (userbase opensmtpd-local-delivery-userbase
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-local-delivery" "userbase"
+                                     (list false? opensmtpd-table?)))))
+  (virtual opensmtpd-local-delivery-virtual
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-local-delivery" "virtual"
+                                    (list false? opensmtpd-table?)))))
+  (wrapper opensmtpd-local-delivery-wrapper
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-local-delivery" "wrapper"
+                                    (list false? string?))))))
+
+;; FIXME/TODO this is a valid opensmtpd-relay record
+;; (opensmtpd-relay
+;;  (pki (opensmtpd-pki
+;;        (domain "gnucode.me")
+;;        (cert "opensmtpd.scm")
+;;        (key "opensmtpd.scm"))))
+;; BUT how does it relay the email?  What host does it use?
+;; I think opensmtpd-relay-configuration needs "method" field.
+;; the method field might need to be another record...BUT basically the relay has to have a 'backup', 'backup-mx',
+;; or 'domain', or 'host' defined.
+(define-record-type* <opensmtpd-relay>
+  opensmtpd-relay make-opensmtpd-relay
+  opensmtpd-relay?
+  (name opensmtpd-relay-name
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "name"
+                                 (list string?))))
+        (default #f))
+  (backup opensmtpd-relay-backup ;; boolean
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "backup"
+                                   (list boolean?)))))
+  (backup-mx opensmtpd-relay-backup-mx ;; string mx name
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-relay" "backup-mx"
+                                      (list false? string?)))))
+  (helo opensmtpd-relay-helo
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "helo"
+                                 (list false? string? opensmtpd-table?))))
+        (default #f))
+  (helo-src opensmtpd-relay-helo-src
+        (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "helo-src"
+                                   (list false? string? opensmtpd-table?))))
+        (default #f))
+  (domain opensmtpd-relay-domain
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "domain"
+                                   (list false? opensmtpd-table?))))
+          (default #f))
+  (host opensmtpd-relay-host
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "host"
+                                 (list false? string?))))
+        (default #f))
+  (pki opensmtpd-relay-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "pki"
+                                (list false? opensmtpd-pki?)))))
+  (srs opensmtpd-relay-srs
+       (default #f)
+       (lambda (var)
+         (my/sanitize var "opensmtpd-relay" "srs"
+                      (list boolean?))))
+  (tls opensmtpd-relay-tls
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "tls"
+                                (list false? string?)))))
+  (auth opensmtpd-relay-auth
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "auth"
+                                 (list false? opensmtpd-table?))))
+        (default #f))
+  (mail-from opensmtpd-relay-mail-from
+             (default #f))
+  ;; string "127.0.0.1" or "<interface>" or "<table of IP addresses>"
+  ;; TODO should I do some sanitizing to make sure that the string? here is actually an IP address or a valid interface?
+  (src opensmtpd-relay-src
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "src"
+                                (list false? string? opensmtpd-table?))))
+       (default #f)))
+
+;; this record is used by <opensmtpd-filter-phase> &
+;; <opensmtpd-match>
+(define-record-type* <opensmtpd-option>
+  opensmtpd-option make-opensmtpd-option
+  opensmtpd-option?
+  (option opensmtpd-option-option
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (and (string? var)
+                               (or (string-in-list? var (list "fcrdns" "rdns"
+                                                          "src" "helo"
+                                                          "auth" "mail-from"
+                                                          "rcpt-to"
+                                                          "for"
+                                                          "for any" "for local"
+                                                          "for domain" "for rcpt-to"
+                                                          "from any" "from auth"
+                                                          "from local" "from mail-from"
+                                                          "from rdns" "from socket"
+                                                          "from src" "auth"
+                                                          "helo" "mail-from"
+                                                          "rcpt-to" "tag" "tls"))))
+                                                          
+                          var
+                          (begin
+                            (display (string-append "<opensmtpd-option> fieldname: 'option' is of type \n"
+                                                    "string.  The string can be either 'fcrdns', \n"
+                                                    " 'rdns', 'src', 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
+                                                    "'for', 'for any', 'for local', 'for domain', 'for rcpt-to', \n"
+                                                    "'from any', 'from auth', 'from local', 'from mail-from', 'from rdns', 'from socket', \n"
+                                                    "'from src', 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"))
+                                                    
+                            (throw 'bad! var))))))
+  (not opensmtpd-option-not
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-option" "not"
+                                (list boolean?)))))
+  (regex opensmtpd-option-regex
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option" "regex"
+                                  (list boolean?)))))
+  (data opensmtpd-option-data
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option" "data"
+                                  (list false? string? opensmtpd-table?))))))
+
+(define-record-type* <opensmtpd-filter-phase>
+  opensmtpd-filter-phase make-opensmtpd-filter-phase
+  opensmtpd-filter-phase?
+  (name opensmtpd-filter-phase-name ;; string chain-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter-phase" "name"
+                                 (list string?)))))
+  (phase opensmtpd-filter-phase-phase ;; string
+              (default #f)
+              (sanitize (lambda (var)
+                          (if (and (string? var)
+                                   (string-in-list? var (list "connect"
+                                                              "helo"
+                                                              "mail-from"
+                                                              "rcpt-to"
+                                                              "data"
+                                                              "commit")))
+                              var
+                              (begin
+                                (display (string-append "<opensmtpd-filter-phase> fieldname: 'phase' is of type \n"
+                                                        "string.  The string can be either 'connect',"
+                                                        " 'helo', 'mail-from', 'rcpt-to', 'data', or 'commit.'\n "))
+
+                                (throw 'bad! var))))))
+  (options opensmtpd-filter-phase-options
+           (default #f)
+           (sanitize (lambda (var)
+                       ;; returns #t if list is a unique list of <opensmtpd-option>
+                       (define (list-of-opensmtpd-option? list)
+                         (and (list-of-type? list opensmtpd-option?)
+                              (not (contains-duplicate? list))))
+
+                       (define (list-has-duplicates-or-non-opensmtpd-option list)
+                         (not (list-of-opensmtpd-option? list)))
+
+                       ;; input <opensmtpd-option>
+                       ;; return #t if <opensmtpd-option> fieldname 'option'
+                       ;; that needs a corresponding table has one.  Otherwise #f
+                       (define (opensmtpd-option-has-table? record)
+                         (define decision (opensmtpd-option-option record))
+                         (and (string? decision)
+                              ;; if option needs a table, check for a table
+                              (if (string-in-list? decision (list "src"
+                                                                  "helo"
+                                                                  "mail-from"
+                                                                  "rcpt-to"))
+                                  (opensmtpd-table? (opensmtpd-option-data record))
+                                  #t)))
+
+                       (define (list-of-opensmtpd-option-has-table? list)
+                         (list-of-type? list opensmtpd-option-has-table?))
+
+                       (define (some-opensmtpd-option-in-list-lack-table? list)
+                         (not (list-of-opensmtpd-option-has-table? list)))
+
+                       (sanitize-options-for-filter-phase-configuration var)
+                       )))
+  (decision opensmtpd-filter-phase-decision
+            (default #f)
+            (sanitize (lambda (var)
+                        (if (and (string? var)
+                                 (string-in-list? var (list "bypass" "disconnect"
+                                                            "reject" "rewrite" "junk")))
+                            var
+                            (begin
+                              (display (string-append "<opensmtpd-filter-decision> fieldname: 'decision' is of type \n"
+                                                      "string.  The string can be either 'bypass',"
+                                                      " 'disconnect', 'reject', 'rewrite', or 'junk'.\n"))
+                              (throw 'bad! var))))))
+  (message opensmtpd-filter-phase-message
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase" "message"
+                                    (list false? string?)))))
+  (value opensmtpd-filter-phase-value
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-filter-phase" "value"
+                                  (list false? number?))))))
+
+(define-record-type* <opensmtpd-filter>
+  opensmtpd-filter make-opensmtpd-filter
+  opensmtpd-filter?
+  (name opensmtpd-filter-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "name"
+                                 (list string?)))))
+  (exec opensmtpd-filter-exec
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "exec"
+                                 (list boolean?)))))
+  (proc opensmtpd-filter-proc ; a string like "rspamd" or the command to start it like "/path/to/rspamd --option=arg --2nd-option=arg2"
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-filter" "proc"
+                                      (list string? list-of-strings-or-gexps?))))))
+
+;; There is another type of filter that opensmtpd supports, which is a filter chain.
+;; A filter chain is a list of <opensmtpd-filter-phase> and <opensmtpd-filter>.
+;; This lets you apply several filters under one filter name.  I could have defined
+;; a record type for it, but the record would only have had two fields: name and list-of-filters.
+;; Why write that as a record?  That's too simple.
+;; returns #t if list is a unique list of <opensmtpd-filter> or <opensmtpd-filter-phase>
+;; returns # otherwise
+(define (opensmtpd-filter-chain? %filters)
+  (and (list-of-unique-filter-or-filter-phase? %filters)
+       (< 1 (length %filters))))
+
+(define-record-type* <opensmtpd-interface>
+  opensmtpd-interface make-opensmtpd-interface
+  opensmtpd-interface?
+  ;; interface may be an IP address, interface group, or domain name
+  (interface opensmtpd-interface-interface
+             (default "lo"))
+  (family opensmtpd-interface-family
+          (default #f)
+          (sanitize (lambda (var)
+                      (cond
+                       ((eq? #f var) ;; var == #f
+                        var)
+                       ((and (string? var)
+                             (string-in-list? var (list "inet4" "inet6")))
+                        var)
+                       (else
+                        (begin
+                          (display "<opensmtpd-interface> fieldname 'family' must be string \"inet4\" or \"inet6\".\n")
+                          (throw 'bad! var)))))))
+  (auth opensmtpd-interface-auth
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "auth"
+                                 (list boolean? table-whose-data-are-assoc-list?)))))
+  (auth-optional opensmtpd-interface-auth-optional
+                 (default #f)
+                 (sanitize (lambda (var)
+                             (my/sanitize var "opensmtpd-interface" "auth-optional"
+                                          (list boolean?
+                                                table-whose-data-are-assoc-list?)))))
+  ;; TODO add a ca entry?
+  ;; string FIXME/TODO sanitize this to support a gexp.  That way way the
+  ;; includes directive can include my hacky scheme code that I use for opensmtpd-dkimsign.
+  (filters opensmtpd-interface-filters
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-filter-phases var))))
+  (hostname opensmtpd-interface-hostname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-interface" "hostname"
+                                     (list false? string?)))))
+  (hostnames opensmtpd-interface-hostnames
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-interface" "hostnames"
+                                      (list false? table-whose-data-are-assoc-list?)))))
+  (mask-src opensmtpd-interface-mask-src
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-interface" "mask-src"
+                                     (list boolean?)))))
+  (disable-dsn opensmtpd-interface-disable-dsn
+          (default #f))
+  (pki opensmtpd-interface-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "pki"
+                                (list false? opensmtpd-pki?)))))
+  (port opensmtpd-interface-port
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "port"
+                                 (list false? integer?)))))
+  (proxy-v2 opensmtpd-interface-proxy-k2
+            (default #f))
+  (received-auth opensmtpd-interface-received-auth
+                 (default #f))
+  ;; TODO add in a senders option!
+  ;; string or <opensmtpd-senders> record
+  ;; (senders opensmtpd-interface-senders
+  ;;          (sanitize (lambda (var)
+  ;;                      (my/sanitize var "opensmtpd-interface" "port" (list false? integer?))))
+  ;;          (default #f))
+  (secure-connection opensmtpd-interface-secure-connection
+                     (default #f)
+                     (sanitize (lambda (var)
+                                 (cond ((boolean? var)
+                                        var)
+                                       ((and (string? var)
+                                             (string-in-list? var
+                                                              (list "smtps" "tls"
+                                                                    "tls-require"
+                                                                    "tls-require-verify")))
+                                        var)
+                                       (else
+                                        (begin
+                                          (display (string-append "<opensmtd-listen-on> fieldname 'secure-connection' can be \n"
+                                                                  "one of the following strings: \n'smtps', 'tls', 'tls-require', \n"
+                                                                  "or 'tls-require-verify'.\n"))
+                                          (throw 'bad! var)))))))
+  (tag opensmtpd-interface-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+(define-record-type* <opensmtpd-socket-configuration>
+  opensmtpd-socket-configuration make-opensmtpd-socket-configuration
+  opensmtpd-socket-configuration?
+  ;; false or <opensmtpd-filter> or list of <opensmtpd-filter>
+  (filters opensmtpd-socket-configuration-filters
+           (sanitize (lambda (var)
+                       (sanitize-filter-phases var)))
+          (default #f))
+  (mask-src opensmtpd-socket-configuration-mask-src
+            (default #f))
+  (tag opensmtpd-socket-configuration-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+
+(define-record-type* <opensmtpd-match>
+  opensmtpd-match make-opensmtpd-match
+  opensmtpd-match?
+  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
+  ;;is #t, then the match record will be a reject match record.
+  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action 'reject))
+  ;; To do this, I will also have to  'reject' mutually exclusive. AND an match with 'reject' can have no action defined.
+  (action opensmtpd-match-action
+          (default #f)
+          (sanitize (lambda (var)
+                      (if (or (opensmtpd-relay? var)
+                              (opensmtpd-local-delivery? var)
+                              (eq? (quote reject) var))
+                          var
+                          (begin
+                            (display
+                             (string-append "<opensmtpd-match> fieldname 'action' is of type <opensmtpd-relay>, \n"
+                                            "<opensmtpd-local-delivery>, or (quote reject).\n"
+                                            "If its var is (quote reject), then the match rejects the incoming message\n"
+                                            "during the SMTP dialogue.\n"))
+                            (throw 'bad! var))))))
+  (options opensmtpd-match-options
+           (default #f)
+           (sanitize (lambda (var)
+                       (cond ((not var)
+                              #f)
+                             ((not (list-of-unique-opensmtpd-option? var))
+                              (throw-error var '("<opensmtpd-match> fieldname 'options' is a list of unique \n"
+                                                 "<opensmtpd-option> records. \n")))
+                           (else (sanitize-list-of-options-for-match-configuration var)))))))
+
+(define-record-type* <opensmtpd-smtp>
+  opensmtpd-smtp make-opensmtpd-smtp
+  opensmtpd-smtp?
+  (ciphers opensmtpd-smtp-ciphers
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-smtp" "ciphers"
+                                    (list false? string?)))))
+  (limit-max-mails opensmtpd-smtp-limit-max-mails
+                   (default #f)
+                   (sanitize (lambda (var)
+                               (my/sanitize var "opensmtpd-smtp" "limit-max-mails"
+                                            (list false? integer?)))))
+  (limit-max-rcpt opensmtpd-smtp-limit-max-rcpt
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp" "limit-max-rcpt"
+                                           (list false? integer?)))))
+  (max-message-size opensmtpd-smtp-max-message-size
+                    (default #f)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-smtp" "max-message-size"
+                                             (list false? integer? string?)))))
+  ;; FIXME/TODO the sanitize function of sub-addr-delim should accept a string of length one not string?
+  (sub-addr-delim opensmtpd-smtp-sub-addr-delim
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp" "sub-addr-delim"
+                                           (list false? integer? string?))))))
+
+(define-record-type* <opensmtpd-srs>
+  opensmtpd-srs make-opensmtpd-srs
+  opensmtpd-srs?
+  ;; TODO should this be a file?
+  (key opensmtpd-srs-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-srs" "key"
+                                (list false? boolean? string?)))))
+  ;; TODO should this also be a file?
+  (backup-key opensmtpd-srs-backup-key
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-srs" "backup-key"
+                                       (list false? integer?)))))
+  (ttl-delay opensmtpd-srs-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-srs" "ttl-delay"
+                                      (list false? string?))))))
+
+(define-record-type* <opensmtpd-queue>
+  opensmtpd-queue make-opensmtpd-queue
+  opensmtpd-queue?
+  (compression opensmtpd-queue-compression
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-queue" "compression"
+                                        (list boolean?)))))
+  (encryption opensmtpd-queue-encryption
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-queue" "encryption"
+                                       (list boolean? string? file-exists?)))))
+  (ttl-delay opensmtpd-queue-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-queue" "ttl-delay"
+                                      (list false? string?))))))
+
 (define-record-type* <opensmtpd-configuration>
   opensmtpd-configuration make-opensmtpd-configuration
   opensmtpd-configuration?
-  (package     opensmtpd-configuration-package
-               (default opensmtpd))
+  (package opensmtpd-configuration-package
+           (default opensmtpd))
   (config-file opensmtpd-configuration-config-file
-               (default %default-opensmtpd-config-file))
+               (default #f))
+  ;; FIXME/TODO should I include a admd authservid entry?
+
+  ;; TODO sanitize this properly with perhaps a <sanitize-configuration>.
+  (bounce opensmtpd-configuration-bounce
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-configuration" "bounce"
+                                   (list false? list?)))))
+  (cas opensmtpd-configuration-cas
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "cas"
+                                (list false? list-of-opensmtpd-ca?)))))
+  ;; list of many records of type opensmtpd-interface
+  (listen-ons opensmtpd-configuration-listen-ons
+              (default (list (opensmtpd-interface)))
+              (sanitize (lambda (var)
+                          (if (list-of-opensmtpd-interface? var)
+                              var
+                              (begin
+                                (display "<opensmtpd-configuration> fieldname 'listen-ons' expects a list of records ")
+                                (display "of one or more unique <opensmtpd-interface> records.\n")
+                                (throw 'bad! var))))))
+  ;; accepts type <opensmtpd-socket-configuration>
+  (listen-on-socket opensmtpd-configuration-listen-on-socket
+                    (default (opensmtpd-socket-configuration)))
+  (includes opensmtpd-configuration-includes ;; list of strings of absolute path names
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-configuration" "includes"
+                                     (list false? list-of-strings? gexp?)))))
+  (matches opensmtpd-configuration-matches
+           (default (list (opensmtpd-match
+                           (action (opensmtpd-local-delivery
+                                    (name "local")
+                                    (method "mbox")))
+                           (options (list
+                                     (opensmtpd-option
+                                      (option "for local")))))
+                          (opensmtpd-match
+                           (action (opensmtpd-relay
+                                    (name "outbound")))
+                           (options (list
+                                     (opensmtpd-option
+                                      (option "from local"))
+                                     (opensmtpd-option
+                                      (option "for any")))))))
+           ;; TODO perhaps I should sanitize this function like I sanitized the 'filters'.
+           ;; I definitely should sanitize this function a bit more.  For example, you could have two different
+           ;; actions, one for local delivery and one for remote, with the same name.  I should make sure that
+           ;; I have no two different actions with the same name.
+           (sanitize (lambda (var)
+                       ;; Should we do more sanitizing here?  eg: "from socket" should NOT have a table or value
+                       var
+                       (my/sanitize var "opensmtpd-configuration" "matches"
+                                    (list list-of-unique-opensmtpd-match?)))))
+  ;; list of many records of type mda-wrapper
+  ;; TODO/FIXME support using gexps here
+  ;; eg (list "name" gexp)
+  (mda-wrappers opensmtpd-configuration-mda-wrappers
+                (default #f)
+                (sanitize (lambda (var)
+                            (my/sanitize var
+                                         "opensmtpd-configuration"
+                                         "mda-wrappers"
+                                         (list false? string?)))))
+  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
+                    (default 100)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-configuration" "mta-max-deferred"
+                                             (list number?)))))
+
+  ;; TODO should I add a fieldname proc _proc-name_ _command_ as found in the man 5 smtpd.conf ?
+
+  (queue opensmtpd-configuration-queue
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-configuration" "queue"
+                                  (list false? opensmtpd-queue?)))))
+  (smtp opensmtpd-configuration-smtp
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-configuration" "smtp"
+                                 (list false? opensmtpd-smtp?)))))
+  (srs opensmtpd-configuration-srs
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "srs"
+                                (list false? opensmtpd-srs?)))))
   (setgid-commands? opensmtpd-setgid-commands? (default #t)))
 
+;; this help procedure is used 3 or 4 times by sanitize-list-of-options-for-match-configuration
+(define* (throw-error-duplicate-option option error-arg #:key (record-name "match"))
+  (throw-error error-arg
+               (list (string-append "<opensmtpd-" record-name ">'s fieldname 'options' has two\n")
+                     (string-append "<opensmtpd-option> records with fieldname 'option' with value '" option "'. \n")
+                     (string-append "You can only have one option with value '" option "' in the options list.\n"))))
+
+;; this procedure sanitizes the fieldname opensmtpd-match-options
+(define* (sanitize-list-of-options-for-match-configuration %options)
+  (let loop ((%traversing-options %options)
+             ;; sanitized-options is an alist that may end of looking like:
+             ;; (("for" (opensmtpd-option (option "for any")))
+             ;;  ("from" (opensmtpd-option (option "from any"))))
+             (%sanitized-options '()))
+    (if (null? %traversing-options)
+        (remove false?
+                (list
+                 (assoc-ref %sanitized-options "for")
+                 (assoc-ref %sanitized-options "from")
+                 (assoc-ref %sanitized-options "auth")
+                 (assoc-ref %sanitized-options "helo")
+                 (assoc-ref %sanitized-options "mail-from")
+                 (assoc-ref %sanitized-options "rcpt-to")
+                 (assoc-ref %sanitized-options "tag")
+                 (assoc-ref %sanitized-options "tls")))
+        (let* ((option-record (car %traversing-options))
+               (option-string (opensmtpd-option-option option-record)))
+          (cond ((string=? "auth" option-string)
+                 (if (assoc-ref %sanitized-options "auth")
+                     (throw-error-duplicate-option "auth" %traversing-options)
+                     (loop (cdr %traversing-options) (alist-cons "auth" option-record %sanitized-options))))
+                ((string=? "helo" option-string)
+                 (cond [(assoc-ref %sanitized-options "helo")
+                        (throw-error-duplicate-option "helo" %traversing-options)]
+                       [(not (opensmtpd-option-data option-record))
+                        (throw-error option-record
+                                     (list "<opensmtpd-option> with fieldname 'option' with value 'helo' \n"
+                                           "must have a 'data' of type string or <opensmtpd-table>.\n"))]
+                       [else (loop (cdr %traversing-options) (alist-cons "helo" option-record %sanitized-options))]))
+                ((string=? "mail-from" option-string)
+                 (cond ((assoc-ref %sanitized-options "mail-from")
+                        (throw-error-duplicate-option "mail-from" %traversing-options))
+                       ((not (opensmtpd-option-data option-record))
+                        (throw-error option-record
+                                     (list "<opensmtpd-option> with fieldname 'option' with value 'mail-from' \n"
+                                           "must have a 'data' of type string or <opensmtpd-table>.\n")))
+                       (else (loop (cdr %traversing-options) (alist-cons "mail-from" option-record %sanitized-options)))))
+                ((string=? "rcpt-to" option-string)
+                 (cond [(assoc-ref %sanitized-options "rcpt-to")
+                        (throw-error-duplicate-option "rcpt-to" %traversing-options)]
+                       [(not (opensmtpd-option-data option-record))
+                        (throw-error option-record
+                                     (list "<opensmtpd-option> with fieldname 'option' with value 'rcpt-to' \n"
+                                           "must have a 'data' of type string or <opensmtpd-table>.\n"))]
+                       [else (loop (cdr %traversing-options) (alist-cons "rcpt-to" option-record %sanitized-options))]))
+                ((string=? "tag" option-string)
+                 (cond ((assoc-ref %sanitized-options "tag")
+                        (throw-error-duplicate-option "tag" %traversing-options))
+                       ((not (string? (opensmtpd-option-data option-record)))
+                        (throw-error option-record
+                                     (list "<opensmtpd-option> with fieldname 'option' with value 'tag' \n"
+                                           "must have a 'data' of type string.\n")))
+                       (else (loop (cdr %traversing-options) (alist-cons "tag" option-record %sanitized-options)))))
+                ((string=? "tls" option-string)
+                 (cond [(assoc-ref %sanitized-options "tls")
+                        (throw-error-duplicate-option "tls" %traversing-options)]
+                       [(or (opensmtpd-option-data option-record)
+                            (opensmtpd-option-regex option-record))
+                        (throw-error option-record
+                                     (list "<opensmtpd-option> with fieldname 'option' with value 'tls', then \n"
+                                           "fieldname 'data' cannot be defined.\n"))]
+                       [else (loop (cdr %traversing-options) (alist-cons "tls" option-record %sanitized-options))]))
+                ((string=? "for" (substring option-string 0 3))
+                 (cond ((assoc-ref %sanitized-options "for")
+                        (throw-error %options
+                                     `("<opensmtpd-match>'s fieldname 'options' can only have one 'for' option. \n"
+                                       "But '" ,option-string "' and '"
+                                       ,(opensmtpd-option-option (assoc-ref %sanitized-options "for")) "' are present.\n")))
+                       ((and (string-in-list? option-string (list "for any" "for local")) ; for any cannot have a data field.
+                             (or (opensmtpd-option-data option-record)
+                                 (opensmtpd-option-regex option-record)))
+                        (throw-error option-record
+                                     (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for any' \n"
+                                           "or 'for local', then its 'data' and 'regex' field must be #f. \n")))
+                       ((and (string-in-list? option-string (list "for domain" "for rcpt-to")) ; for domain must have a data field.
+                             (not (opensmtpd-option-data option-record)))
+                        (throw-error option-record
+                                     (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'for domain' \n"
+                                           "or 'for rcpt-to', then its 'data' field must be a string or an \n"
+                                           "<opensmtpd-table> record.\n")))
+                       (else (loop (cdr %traversing-options) (alist-cons "for" option-record %sanitized-options)))))
+                ((string=? "from" (substring option-string 0 4))
+                 (cond ((assoc-ref %sanitized-options "from")
+                        (throw-error %options
+                                     `("<opensmtpd-match>'s fieldname 'options' can only have one 'from' option. \n"
+                                       "But '" ,option-string "' and '"
+                                       ,(opensmtpd-option-option (assoc-ref %sanitized-options "from")) "' are present.\n")))
+                       ((and (string-in-list? option-string (list "from any" "from local" "from socket")) ; for any cannot have a data field.
+                             (or (opensmtpd-option-data option-record)
+                                 (opensmtpd-option-regex option-record)))
+                        (throw-error option-record
+                                     (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from any', \n"
+                                           " 'from local', or 'from socket', then its 'data' and 'regex' field must be #f. \n")))
+                       ((and (string-in-list? option-string (list "from mail-from" "from src")) ; for domain must have a data field.
+                             (not (opensmtpd-option-data option-record)))
+                        (throw-error option-record
+                                     (list "When <openmstpd-option-configuration>'s fieldname 'options' value is 'from mail-from' \n"
+                                           "or 'from src', then its 'data' field must be a string or an \n"
+                                           "<opensmtpd-table> record.\n")))
+                       (else (loop (cdr %traversing-options) (alist-cons "from" option-record %sanitized-options))))))))))
+
+;; if the list of filters in opensmtpd-interface-filters
+;; and in opensmtpd-socket-configuration-filters has two
+;; filters with the same name, this will return #t
+;; otherwise false
+(define (duplicate-filter-name? %filters)
+  (contains-duplicate?
+   (let loop ((%filters %filters))
+     (if (null? %filters)
+         '()
+         (cond
+          ((opensmtpd-filter-phase? (car %filters))
+           (cons (opensmtpd-filter-phase-name (car %filters))
+                 (loop (cdr %filters))))
+          (else
+           (cons (opensmtpd-filter-name (car %filters))
+                 (loop (cdr %filters)))))))))
+
+(define (list-has-duplicates-or-non-filters? list)
+  (not (list-of-unique-filter-or-filter-phase? list)))
+
+(define (filter-phase-has-message-and-value? record)
+  (and (opensmtpd-filter-phase-message record)
+       (opensmtpd-filter-phase-value record)))
+
+;; return #t if phase needs a message. Or if the message did not start with a 4xx or 5xx status code.
+;; otherwise #f
+(define (filter-phase-decision-lacks-proper-message? record)
+  (define decision (opensmtpd-filter-phase-decision record))
+  (if (string-in-list? decision (list "disconnect" "reject"))
+      ;; this message needs to be RFC compliant, meaning
+      ;; that it need to start with 4xx or 5xx status code
+      (cond ((eq? #f (opensmtpd-filter-phase-message record))
+             #t)
+            ((string? (opensmtpd-filter-phase-message record))
+             (let ((number (string->number
+                            (substring
+                             (opensmtpd-filter-phase-message record) 0 3))))
+               (if (and (number? number)
+                        (and (< number 600) (> number 399)))
+                   #f
+                   #t))))
+      #f))
+
+;; 'decision' "rewrite" requires 'value' to be a number.
+(define (filter-phase-lacks-proper-value? record)
+  (define decision (opensmtpd-filter-phase-decision record))
+  (if (string=? "rewrite" decision)
+      (if (and (number? (opensmtpd-filter-phase-value record))
+               (eq? #f (opensmtpd-filter-phase-message record)))
+          #f
+          #t)
+      #f))
+
+;; 'decision' "junk" or "bypass" cannot have a message or a value.
+(define (filter-phase-has-incorrect-junk-or-bypass? record)
+  (and
+   (string-in-list?
+    (opensmtpd-filter-phase-decision record)
+    (list "junk" "bypass"))
+   (or
+    (opensmtpd-filter-phase-value record)
+    (opensmtpd-filter-phase-message record))))
+
+(define (filter-phase-junks-after-commit? record)
+  (and (string=? (opensmtpd-filter-phase-decision record) "junk")
+       (string=? (opensmtpd-filter-phase-phase record) "commit")))
+
+;; returns #t if list is a unique list of <opensmtpd-filter> or <opensmtpd-filter-phase>
+;; returns # otherwise
+(define (list-of-unique-filter-or-filter-phase? %filters)
+  (and (list? %filters)
+       (not (null? %filters))
+       ;; this list is made up of only <opensmtpd-filter-phase> or <opensmtpd-filter>
+       (primitive-eval
+        (cons 'and (map (lambda (filter)
+                          (or (opensmtpd-filter? filter)
+                              (opensmtpd-filter-phase? filter)))
+                        %filters)))
+       (not (contains-duplicate? %filters))))
+
+;; the sanitize procedures used for sanitizing <opensmtpd-interface> and
+;; <opensmtpd-socket-configuration> fieldname 'filters'.
+;; It primarily sanitizes <filter-phases>.  The only sanitization it does
+;; for <filter>s, is no make sure there are no duplicate filter names.
+(define (sanitize-filter-phases %list)
+  ;; the order of the first two tests in this cond is important.
+  ;; (false?) has to be 1st and (list-has-duplicates-or-non-filters?) has to be second.
+  ;; You may optionally re-order the other alternates in the cond.
+  (cond ((false? %list)
+         #f)
+        ((list-has-duplicates-or-non-filters? %list)
+         (begin
+           (display (string-append "<opensmtpd-interface> fieldname: 'filters' is a list, in which each unique element \n"
+                                   "is of type <opensmtpd-filter> or <opensmtpd-filter-phase>.\n"))
+           (throw 'bad! %list)))
+        ((duplicate-filter-name? %list)
+         (throw-error %list (list "has a duplicate filter name.\n")
+                      #:record-name "interface"
+                      #:fieldname "filters"))
+        (else
+         (let loop ([%traversing-list %list]
+                    [%original-list %list])
+           (if (null? %traversing-list)
+               %original-list
+               (cond [(opensmtpd-filter? (car %traversing-list))
+                      (loop (cdr %traversing-list) %original-list)]
+                     [(filter-phase-has-message-and-value? (car %traversing-list))
+                      (begin
+                        (display (string-append "<opensmtpd-filter-phase> cannot have defined fieldnames 'value' \n"
+                                                "and 'message'.\n"))
+                        (throw 'bad! (car %traversing-list)))]
+                     [(filter-phase-decision-lacks-proper-message? (car %traversing-list))
+                      (begin
+                        (display (string-append "<opensmtpd-filter-phase> fieldname: 'decision' options \n"
+                                                "\"disconnect\" and \"reject\" require fieldname 'message' to have an RFC \n"
+                                                "compliant string, which means that the string must begin with a 4xx or 5xx status code.\n"))
+                        (throw 'bad! (car %traversing-list)))]
+                     [(filter-phase-lacks-proper-value? (car %traversing-list))
+                      (begin
+                        (display (string-append "<opensmtpd-filter-phase> fieldname: 'decision' option \n"
+                                                "\"rewrite\" requires fieldname 'value' to have a number.\n"))
+                        (throw 'bad! (car %traversing-list)))]
+                     [(filter-phase-has-incorrect-junk-or-bypass? (car %traversing-list))
+                      (begin
+                        (display (string-append "<opensmtpd-filter-phase> fieldname 'decision' option \n"
+                                                "\"junk\" or 'bypass' cannot have a defined fieldnames 'message' or 'value'.\n"))
+                        (throw 'bad! (car %traversing-list)))]
+                     [(filter-phase-junks-after-commit? (car %traversing-list))
+                      (begin
+                        (display (string-append "<opensmtpd-filter-phase> fieldname 'decision' option \n"
+                                                "\"junk\" cannot junk an email during 'phase' \"commit\".\n"))
+                        (throw 'bad! (car %traversing-list)))]
+                     [else (loop (cdr %traversing-list) %original-list)]))))))
+
+(define* (sanitize-options-for-filter-phase-configuration %options)
+  (if (false? %options)
+      (throw-error #f
+                   (list "must have at least one opensmtpd-option record.")
+                   #:record-name "filter-phase"
+                   #:fieldname "options")
+      (let loop ((%traversing-options %options)
+                 ;; sanitized-options is an alist that may end of looking like:
+                 ;; (("for" (opensmtpd-option (option "for any")))
+                 ;;  ("from" (opensmtpd-option (option "from any"))))
+                 (%sanitized-options '()))
+        (if (null? %traversing-options)
+            (remove false?
+                    (list
+                     (assoc-ref %sanitized-options "fcrdns")
+                     (assoc-ref %sanitized-options "rdns")
+                     (assoc-ref %sanitized-options "src")
+                     (assoc-ref %sanitized-options "helo")
+                     (assoc-ref %sanitized-options "auth")
+                     (assoc-ref %sanitized-options "mail-from")
+                     (assoc-ref %sanitized-options "rcpt-to")))
+            (let* ((option-record (car %traversing-options))
+                   (option-string (opensmtpd-option-option option-record)))
+              (cond ((assoc-ref %sanitized-options option-string)
+                     ;; if we see two "rdns" (for example), throw a "duplicate
+                     ;; option" error.
+                     (throw-error-duplicate-option option-string option-record
+                                                   #:record-name "filter-phase"))
+                    ;; the next 4 options must have fieldname 'data' defined.
+                    ((or (string=? option-string "src")
+                         (string=? option-string "helo")
+                         (string=? option-string "mail-from")
+                         (string=? option-string "rcpt-to"))
+                     (if (not (opensmtpd-table?
+                               (opensmtpd-option-data option-record)))
+                         (throw-error option-record (list "must have fieldname 'data' defined.\n")
+                                      #:record-name "option"
+                                      #:fieldname option-string)
+                         (loop (cdr %traversing-options)
+                               (alist-cons option-string option-record %sanitized-options))))
+                    ;;fcrdns cannot have fieldname data defined
+                    ((string=? "fcrdns" option-string)
+                     (if (opensmtpd-option-data option-record)
+                         (throw-error option-record (list "cannot have fieldname data defined.\n")
+                                      #:record-name "option"
+                                      #:fieldname "rdns")
+                         (loop (cdr %traversing-options)
+                               (alist-cons "fcrdns" option-record %sanitized-options))))
+                    ;; rdns and auth cannot be made invalidly; skip testing them.
+                    ((or (string=? "rdns" option-string)
+                         (string=? "auth" option-string))
+                     (loop (cdr %traversing-options)
+                           (alist-cons "auth" option-record
+                                       %sanitized-options)))
+                    (else (throw-error option-record
+                                       (list "has an invalid option name.")
+                                       #:record-name "filter-phase"
+                                       #:fieldname option-string))))))))
+
+(define* (throw-error var %strings
+                      #:key
+                      (record-name #f)
+                      (fieldname #f))
+  (if (and record-name fieldname)
+      (begin
+        (display (string-append "<opensmtpd-" record-name "> fieldname " fieldname " "
+                                (apply string-append %strings)))
+        (throw 'bad! var))
+      (begin
+        (display (apply string-append %strings))
+        (throw 'bad! var))))
+
+;; this is used for sanitizing <opensmtpd-filter-phase> fieldname 'options'
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+      ;; check if (car list) is in (cdr list)
+       (primitive-eval (cons 'or
+                                (map (lambda (var) (equal? var (car list)))
+                                     (cdr list))))
+       ;; check if (cdr list) contains duplicate
+       (contains-duplicate? (cdr list)))))
+
+;; given a list and procedure, this tests that each element of list is of type
+;; ie: (list-of-type? list string?) tests each list is of type string.
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ((list list))
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+
+(define (list-of-strings? list)
+  (list-of-type? list string?))
+
+(define (list-of-unique-opensmtpd-option? list)
+  (and (list-of-type?
+        list opensmtpd-option?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-opensmtpd-ca? list)
+  (list-of-type? list opensmtpd-ca?))
+
+(define (list-of-opensmtpd-pki? list)
+  (list-of-type? list opensmtpd-pki?))
+
+(define (list-of-opensmtpd-interface? list)
+  (and (list-of-type? list opensmtpd-interface?)
+       (not (contains-duplicate? list))))
+
+(define (list-of-unique-opensmtpd-match? list)
+  (and (list-of-type? list opensmtpd-match?)
+       (not (contains-duplicate? list))))
+
+(define* (list-of-strings->string list
+                                  #:key
+                                  (string-delimiter ", ")
+                                  (postpend "")
+                                  (append "")
+                                  (drop-right-number 2))
+  (string-drop-right
+   (string-append (let loop ((list list))
+                    (if (null? list)
+                        ""
+                        (string-append append (car list) postpend
+                                       string-delimiter
+                                       (loop (cdr list)))))
+                  append)
+   drop-right-number))
+
+;; at the moment I cannot define this by using list-of-type?
+;; the first (not (null? assoc-list)) prevents that.
+(define (assoc-list? assoc-list)
+  (list-of-type? assoc-list (lambda (pair)
+                              (if (and (pair? pair)
+                                       (string? (car pair))
+                                       (string? (cdr pair)))
+                                  #t
+                                  #f))))
+
+(define* (variable->string var #:key (append "") (postpend " "))
+  (let ((var (if (number? var)
+                 (number->string var)
+                 var)))
+    (if var
+        (string-append append var postpend)
+        "")))
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table> whose fieldname 'values' is an assoc-list, then it returns
+;; #t, #f if otherwise.
+;; TODO should I remove these two functions?  And instead use the (opensmtpd-table-type) procedure?
+(define (table-whose-data-are-assoc-list? table)
+  (if (not (opensmtpd-table? table))
+      #f
+      (assoc-list? (opensmtpd-table-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table> whose fieldname 'values' is a list of strings, then it returns
+;; #t, #f if otherwise.
+(define (table-whose-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table? table))
+      #f
+      (list-of-strings? (opensmtpd-table-data table))))
+
+;; these next few functions help me to turn <table>s
+;; into strings suitable to fit into "opensmtpd.conf".
+(define (assoc-list->string assoc-list)
+  (string-drop-right
+   (let loop ((assoc-list assoc-list))
+     (if (null? assoc-list)
+         ""
+         ;; pair is (cons "hello" "world") -> ("hello" . "world")
+         (let ((pair (car assoc-list)))
+           (string-append
+            "\"" (car pair)  "\""
+            " = "
+            "\"" (cdr pair) "\""
+            ", "
+            (loop (cdr assoc-list))))))
+   2))
+
+;;  The following functions convert various records into strings.
+;;
+;; can be of type: (quote list-of-strings) or (quote assoc-list)
+(define (opensmtpd-table->string table)
+  (string-append "table " (opensmtpd-table-name table) " "
+                 (let ((type (opensmtpd-table-type table)))
+                   (cond ((eq? type (quote list-of-strings))
+                          (string-append "{ " (list-of-strings->string (opensmtpd-table-data table)
+                                                                       #:append "\""
+                                                                       #:drop-right-number 3
+                                                                       #:postpend "\"") " }"))
+                         ((eq? type (quote assoc-list))
+                          (string-append "{ " (assoc-list->string (opensmtpd-table-data table)) " }"))
+                         ((eq? type (quote db))
+                          (string-append "db:" (opensmtpd-table-data table)))
+                         ((eq? type (quote file))
+                          (string-append "file:" (opensmtpd-table-data table)))
+                         (else (throw 'youMessedUp table))))
+                 " \n"))
+
+(define (opensmtpd-interface->string record)
+  (string-append "listen on "
+                 (opensmtpd-interface-interface record) " "
+                 (let* ((hostname (opensmtpd-interface-hostname record))
+                        (hostnames (if (opensmtpd-interface-hostnames record)
+                                       (opensmtpd-table-name (opensmtpd-interface-hostnames record))
+                                       #f))
+                        (filters (opensmtpd-interface-filters record))
+                        (filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter? (car filters))
+                                                 (opensmtpd-filter-name (car filters))
+                                                 (opensmtpd-filter-phase-name (car filters))))
+                                         #f))
+                        (mask-src (opensmtpd-interface-mask-src record))
+                        (tag (opensmtpd-interface-tag record))
+                        (secure-connection (opensmtpd-interface-secure-connection record))
+                        (port (opensmtpd-interface-port record))
+                        (pki (opensmtpd-interface-pki record))
+                        (auth (opensmtpd-interface-auth record))
+                        (auth-optional (opensmtpd-interface-auth-optional record)))
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string hostname #:append "hostname ")
+                    (variable->string hostnames #:append "hostnames <" #:postpend "> ")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    (if secure-connection
+                        (cond ((string=? "smtps" secure-connection)
+                               "smtps ")
+                              ((string=? "tls" secure-connection)
+                               "tls ")
+                              ((string=? "tls-require" secure-connection)
+                               "tls-require ")
+                              ((string=? "tls-require-verify" secure-connection)
+                               "tls-require verify "))
+                        "")
+                    (variable->string port #:append "port " #:postpend " ")
+                    (if pki
+                        (variable->string (opensmtpd-pki-domain pki) #:append "pki ")
+                        "")
+                    (if auth
+                        (string-append "auth "
+                                       (if (opensmtpd-table? auth)
+                                           (string-append "<" (opensmtpd-table-name auth) "> ")
+                                           ""))
+                        "")
+                    (if auth-optional
+                        (string-append "auth-optional "
+                                       (if (opensmtpd-table? auth-optional)
+                                           (string-append "<" (opensmtpd-table-name auth-optional) "> ")
+                                           ""))
+                        "")
+                    "\n"))))
+
+(define (opensmtpd-socket->string record)
+  (string-append "listen on socket "
+                 (let* ((filters (opensmtpd-socket-configuration-filters record))
+                        (filter-name (if filters
+                                         (if (< 1 (length filters))
+                                             (generate-filter-chain-name filters)
+                                             (if (opensmtpd-filter? (car filters))
+                                                 (opensmtpd-filter-name (car filters))
+                                                 (opensmtpd-filter-phase-name (car filters))))
+                                         #f))
+                        (mask-src (opensmtpd-socket-configuration-mask-src record))
+                        (tag (opensmtpd-socket-configuration-tag record)))
+                   (string-append
+                    (if mask-src
+                        (string-append "mask-src ")
+                        "")
+                    (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+                    (variable->string tag #:append "tag \"" #:postpend "\" ")
+                    "\n"))))
+
+(define (opensmtpd-relay->string record)
+  (let ((backup (opensmtpd-relay-backup record))
+        (backup-mx (opensmtpd-relay-backup-mx record))
+        (helo (opensmtpd-relay-helo record))
+        ;; helo-src can either be a string IP address or an <opensmtpd-table>
+        (helo-src (if (opensmtpd-relay-helo-src record)
+                      (if (string? (opensmtpd-relay-helo-src record))
+                          (opensmtpd-relay-helo-src record)
+                          (string-append "<\""
+                                         (opensmtpd-table-name
+                                          (opensmtpd-relay-src record))
+                                         "\">"))
+                      #f))
+        (domain (if (opensmtpd-relay-domain record)
+                    (opensmtpd-table-name
+                     (opensmtpd-relay-domain record))
+                    #f))
+        (host (opensmtpd-relay-host record))
+        (name (opensmtpd-relay-name record))
+        (pki (if (opensmtpd-relay-pki record)
+                 (opensmtpd-pki-domain (opensmtpd-relay-pki record))
+                 #f))
+        (srs (opensmtpd-relay-srs record))
+        (tls (opensmtpd-relay-tls record))
+        (auth (if (opensmtpd-relay-auth record)
+                  (opensmtpd-table-name
+                   (opensmtpd-relay-auth record))
+                  #f))
+        (mail-from (opensmtpd-relay-mail-from record))
+        ;; src can either be a string IP address or an <opensmtpd-table>
+        (src (if (opensmtpd-relay-src record)
+                 (if (string? (opensmtpd-relay-src record))
+                     (opensmtpd-relay-src record)
+                     (string-append "<\""
+                                    (opensmtpd-table-name
+                                     (opensmtpd-relay-src record))
+                                    "\">"))
+                 #f)))
+        
+    (string-append
+     "\""
+     name
+     "\" " "relay "
+     ;;FIXME should I always quote the host fieldname? do I need to quote localhost via "localhost" ?
+     (variable->string host #:append "host \"" #:postpend "\" ")
+     (variable->string backup)
+     (variable->string backup-mx #:append "backup mx ")
+     (variable->string helo #:append "helo ")
+     (variable->string helo-src #:append "helo-src ")
+     (variable->string domain #:append "domain <\"" #:postpend "\"> ")
+     (variable->string host #:append "host ")
+     (variable->string pki #:append "pki ")
+     (variable->string srs)
+     (variable->string tls #:append "tls ")
+     (variable->string auth #:append "auth <" #:postpend "> ")
+     (variable->string mail-from #:append "mail-from ")
+     (variable->string src #:append "src ")
+     "\n")))
+
+(define (opensmtpd-lmtp->string record)
+  (string-append "lmtp "
+                 (opensmtpd-lmtp-destination record)
+                 (if (opensmtpd-lmtp-rcpt-to record)
+                     (begin
+                       " " (opensmtpd-lmtp-rcpt-to record))
+                     "")))
+
+(define (opensmtpd-mda->string record)
+  (string-append "mda "
+                 (opensmtpd-mda-command record) " "))
+
+(define (opensmtpd-maildir->string record)
+  (string-append "maildir "
+                 "\""
+                 (if (opensmtpd-maildir-pathname record)
+                     (opensmtpd-maildir-pathname record)
+                     "~/Maildir")
+                 "\""
+                 (if (opensmtpd-maildir-junk record)
+                     " junk "
+                     " ")))
+
+(define (opensmtpd-local-delivery->string record)
+  (let ((name (opensmtpd-local-delivery-name record))
+        (method (opensmtpd-local-delivery-method record))
+        (alias (if (opensmtpd-local-delivery-alias record)
+                   (opensmtpd-table-name
+                    (opensmtpd-local-delivery-alias record))
+                   #f))
+        (ttl (opensmtpd-local-delivery-ttl record))
+        (user (opensmtpd-local-delivery-user record))
+        (userbase (if (opensmtpd-local-delivery-userbase record)
+                      (opensmtpd-table-name
+                       (opensmtpd-local-delivery-userbase record))
+                      #f))
+        (virtual (if (opensmtpd-local-delivery-virtual record)
+                     (opensmtpd-table-name
+                      (opensmtpd-local-delivery-virtual record))
+                     #f))
+        (wrapper (opensmtpd-local-delivery-wrapper record)))
+    (string-append
+     "\"" name "\" "
+     (cond ((string? method)
+            (string-append method " "))
+           ((opensmtpd-mda? method)
+            (opensmtpd-mda->string method))
+           ((opensmtpd-lmtp? method)
+            (opensmtpd-lmtp->string method))
+           ((opensmtpd-maildir? method)
+            (opensmtpd-maildir->string method)))
+     ;; FIXME/TODO support specifying alias file:/path/to/alias-file  ?
+     ;; I do not think that is something that I can do...
+     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
+     (variable->string ttl #:append "ttl ")
+     (variable->string user #:append "user ")
+     (variable->string userbase #:append "userbase <\"" #:postpend "\"> ")
+     (variable->string virtual #:append "virtual <" #:postpend "> ")
+     (variable->string wrapper #:append "wrapper "))))
+
+;; this function turns both opensmtpd-local-delivery and
+;; opensmtpd-relay into strings.
+(define (opensmtpd-action->string record)
+  (string-append "action "
+                 (cond ((opensmtpd-local-delivery? record)
+                        (opensmtpd-local-delivery->string record))
+                       ((opensmtpd-relay? record)
+                        (opensmtpd-relay->string record)))
+                 " \n"))
+
+;; this turns option records found in <opensmtpd-match> into strings.
+(define* (opensmtpd-option->string record
+                                                 #:key
+                                                 (space-after-! #f))
+  (let ((not (opensmtpd-option-not record))
+        (option (opensmtpd-option-option record))
+        (regex (opensmtpd-option-regex record))
+        (data (opensmtpd-option-data record)))
+    (string-append
+     (if not
+         (if space-after-!
+             "! "
+             "!")
+         "")
+     option " "
+     (if regex
+         "regex "
+         "")
+     (if data
+         (if (opensmtpd-table? data)
+             (string-append "<" (opensmtpd-table-name data) "> ")
+             (string-append data " "))
+         ""))))
+
+(define (opensmtpd-match->string record)
+  (string-append "match "
+                 (let* ((action (opensmtpd-match-action record))
+                        (name (cond [(opensmtpd-relay? action)
+                                     (opensmtpd-relay-name action)]
+                                    [(opensmtpd-local-delivery? action)
+                                     (opensmtpd-local-delivery-name action)]
+                                    [else 'reject]))
+                        (options (opensmtpd-match-options record)))
+                   (string-append
+                    (if options
+                        (apply string-append
+                               (map opensmtpd-option->string options))
+                        "")
+                    (if (string? name)
+                        (string-append "action " "\"" name "\" ")
+                        "reject ")
+                    "\n"))))
+
+(define (opensmtpd-ca->string record)
+  (string-append "ca " (opensmtpd-ca-name record) " "
+                 "cert \"" (opensmtpd-ca-file record) "\"\n"))
+
+(define (opensmtpd-pki->string record)
+  (let ((domain (opensmtpd-pki-domain record))
+        (cert (opensmtpd-pki-cert record))
+        (key (opensmtpd-pki-key record))
+        (dhe (opensmtpd-pki-dhe record)))
+    (string-append "pki " domain " " "cert \"" cert "\" \n"
+                   "pki " domain " " "key \"" key "\" \n"
+                   (if dhe
+                       (string-append
+                        "pki " domain " " "dhe " dhe "\n")
+                       ""))))
+
+(define (generate-filter-chain-name list-of-filters)
+  (string-drop-right (apply string-append
+                            (flatten
+                             (map (lambda (filter)
+                                    (list
+                                     (if (opensmtpd-filter? filter)
+                                         (opensmtpd-filter-name filter)
+                                         (opensmtpd-filter-phase-name filter))
+                                     "-"))
+                                  list-of-filters)))
+                     1))
+
+;; this procedure takes in a list of <opensmtpd-filter> and <opensmtpd-filter-phase>,
+;; returns a string of the form:
+;; filter "uniquelyGeneratedName" chain chain { "filter-name", "filter-name2" [, ...]}
+(define (opensmtpd-filter-chain->string list-of-filters)
+  (string-append "filter \""
+                 (generate-filter-chain-name list-of-filters)
+                 "\" "
+                 "chain {"
+                 (string-drop-right
+                  (apply string-append
+                         (flatten
+                          (map (lambda (filter)
+                                 (list
+                                  "\""
+                                  (if (opensmtpd-filter? filter)
+                                      (opensmtpd-filter-name filter)
+                                      (opensmtpd-filter-phase-name filter))
+                                  "\", "))
+                               list-of-filters)))
+                  2)
+                 "}\n"))
+
+(define (opensmtpd-filter-phase->string record)
+  (let ((name (opensmtpd-filter-phase-name record))
+        (phase (opensmtpd-filter-phase-phase record))
+        (decision (opensmtpd-filter-phase-decision record))
+        (options (opensmtpd-filter-phase-options record))
+        (message (opensmtpd-filter-phase-message record))
+        (value (opensmtpd-filter-phase-value record)))
+    (string-append "filter "
+                   "\"" name "\" "
+                   "phase " phase " "
+                   "match "
+                   (apply string-append ; turn the options into a string
+                          (flatten
+                           (map (lambda (option)
+                                  (opensmtpd-option->string option #:space-after-! #f))
+                                options)))
+                   " "
+                   decision " "
+                   (if (string-in-list? decision (list "reject" "disconnect"))
+                       (string-append "\"" message "\"")
+                       "")
+                   (if (string=? "rewrite" decision)
+                       (string-append "rewrite " (number->string value))
+                       "")
+                   "\n")))
+
+;; filters elements may be <opensmtpd-filter>, <opensmtpd-filter-phase>,
+;; and lists that look like (list (opensmtpd-filter...) (opensmtpd-filter-phase ...)
+;; ...)
+;; this function converts it to a string.
+;; Consider if a user passed in a valid <opensmtpd-configuration>, whose total valid filters
+;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
+;; look like this: (we will call this list "total filters"):
+;; (list (opensmtpd-filter
+;;         (name "rspamd")
+;;         (proc "rspamd"))
+;;       (list (opensmtpd-filter-phase ; this is a listen-on, with a filter-chain.
+;;               (name "dkimsign")
+;;               ...)
+;;               (opensmtpd-filter
+;;                 (name "rspamd")
+;;                 (proc "rspamd"))))
+;;
+;; did you notice that filter "rspamd" is listed twice?  How do you make sure that it is NOT
+;; printed twice in smtpd.conf?
+;; 1st flatten "total filters", then remove its duplicates.  Then print all of those filters.
+;; 2nd now we go through "total filters", and we only print the non-filter-chains.
+(define (opensmtpd-filters->list-of-strings-and-gexps filters)
+  ;; first display the unique <opensmtpd-filter>s. and <opensmtpd-filter-phase>s.
+  ;; to do this: flatten filters, then remove duplicates.
+  (list
+   (apply string-append
+          (map (lambda (filter)
+                 (if (opensmtpd-filter-phase? filter)
+                     (opensmtpd-filter-phase->string filter)
+                     ""))
+               (delete-duplicates (flatten filters))))
+   ;; print out the filter-configurations
+   ;; would values and or call-with-values and or recieve work here?
+   (list (map (lambda (filter)
+                (if (opensmtpd-filter? filter)
+                    (list "filter "
+                          "\"" (opensmtpd-filter-name filter) "\" "
+                          (if (opensmtpd-filter-exec filter)
+                              "proc-exec "
+                              "proc ")
+                          "\"" (opensmtpd-filter-proc filter) "\""
+                          "\n\n")
+                    ""))
+              (delete-duplicates (flatten filters))))
+   ;; now we have to print the filter chains.
+   (apply string-append
+          (map (lambda (filter)
+                 (cond ((list? filter)
+                        (opensmtpd-filter-chain->string filter))
+                       (else      ; you are a <opensmtpd-filter>
+                        "")))
+               filters))))
+
+(define (opensmtpd-configuration-listen->string string)
+  (string-append
+   "include \"" string "\"\n"))
+
+(define (opensmtpd-configuration-srs->string record)
+  (let ((key (opensmtpd-srs-key record))
+        (backup-key (opensmtpd-srs-backup-key record))
+        (ttl-delay (opensmtpd-srs-ttl-delay record)))
+    (string-append
+     (variable->string key #:append "srs key " #:postpend "\n")
+     (variable->string backup-key #:append "srs key backup " #:postpend "\n")
+     (variable->string ttl-delay #:append "srs ttl " #:postpend "\n")
+     "\n")))
+
+;; TODO make sure all options here work!  I just fixed limit-max-rcpt!
+(define (opensmtpd-smtp->string record)
+  (let ((ciphers (opensmtpd-smtp-ciphers record))
+        (limit-max-mails (opensmtpd-smtp-limit-max-mails record))
+        (limit-max-rcpt (opensmtpd-smtp-limit-max-rcpt record))
+        (max-message-size (opensmtpd-smtp-max-message-size record))
+        (sub-addr-delim (opensmtpd-smtp-sub-addr-delim record)))
+    (string-append
+     (variable->string ciphers #:append "smtp ciphers " #:postpend "\n")
+     (variable->string limit-max-mails #:append "smtp limit max-mails " #:postpend "\n")
+     (variable->string limit-max-rcpt #:append "smtp limit max-rcpt " #:postpend "\n")
+     (variable->string max-message-size #:append "smtp max-message-size " #:postpend "\n")
+     (variable->string sub-addr-delim #:append "smtp sub-addr-delim " #:postpend "\n")
+     "\n")))
+
+(define (opensmtpd-configuration-queue->string record)
+  (let ((compression (opensmtpd-queue-compression record))
+        (encryption (opensmtpd-queue-encryption record))
+        (ttl-delay (opensmtpd-queue-ttl-delay record)))
+    (string-append
+     (if compression
+         "queue compression\n"
+         "")
+     (if encryption
+         (string-append
+          "queue encryption "
+          (if (not (boolean? encryption))
+              encryption
+              "")
+          "\n")
+         "")
+     (if ttl-delay
+         (string-append "queue ttl" ttl-delay "\n")
+         ""))))
+
+;; build a list of <opensmtpd-action> from
+;; opensmtpd-configuration-matches, which is a list of <opensmtpd-match>.
+;; Each <opensmtpd-match> has a fieldname 'action', which accepts an <opensmtpd-action>.
+(define (get-opensmtpd-actions record)
+  (define opensmtpd-actions
+    (let loop ((list (opensmtpd-configuration-matches record)))
+      (if (null? list)
+          '()
+          (cons (opensmtpd-match-action (car list))
+                (loop (cdr list))))))
+  (delete-duplicates (append opensmtpd-actions)))
+
+;; build a list of opensmtpd-pkis from
+;; opensmtpd-configuration-listen-ons and
+;; get-opensmtpd-actions
+(define (get-opensmtpd-pkis record)
+  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT have an opensmtpd-relay?
+  ;; I think so.  And if it did NOT have a relay configuration, then action-pkis would be '() when
+  ;; it needs to be #f.  because if the opensmtpd-configuration has NO pkis, then this function will
+  ;; return '(), when it should return #f.  If it returns '(), then opensmtpd-configuration-fieldname->string will
+  ;; print the string "\n" instead of ""
+  (define action-pkis
+    (let loop1 ((list (get-opensmtpd-actions record)))
+      (if (null? list)
+          '()
+          (if (and (opensmtpd-relay? (car list))
+                   (opensmtpd-relay-pki (car list)))
+              (cons (opensmtpd-relay-pki (car list))
+                    (loop1 (cdr list)))
+              (loop1 (cdr list))))))
+  ;; FIXME/TODO/maybe/wishlist
+  ;; this could be #f aka left blank. aka there are no listen-ons records with pkis.
+  ;; aka there are no lines in the configuration like:
+  ;; listen on eth0 tls pki smtp.gnucode.me in that case the smtpd.conf will have an extra "\n"
+  (define listen-on-pkis
+    (let loop2 ((list (opensmtpd-configuration-listen-ons record)))
+      (if (null? list)
+          '()
+          (if (opensmtpd-interface-pki (car list))
+              (cons (opensmtpd-interface-pki (car list))
+                    (loop2 (cdr list)))
+              (loop2 (cdr list))))))
+  (delete-duplicates (append action-pkis listen-on-pkis)))
+
+;; takes in a <opensmtpd-configuration> and returns a list whose elements are <opensmtpd-filter>,
+;; <opensmtpd-filter-phase>, and a filter-chain.
+;; It returns a list of <opensmtpd-filter> and/or <opensmtpd-filter-phase>
+;; here's an example of what this procedure might return:
+;; (list (opensmtpd-filter...) (opensmtpd-filter-phase ...)
+;;       (openmstpd-filter ...) (opensmtpd-filter-phase ...)
+;;       ;; this next list is a filter-chain.
+;;       (list (opensmtpd-filter-phase ...) (opensmtpd-filter...)))
+;;
+;; This procedure handles filter chains a little odd.
+(define (get-opensmtpd-filters record)
+  (define list-of-listen-on-records (if (opensmtpd-configuration-listen-ons record)
+                                        (opensmtpd-configuration-listen-ons record)
+                                        '()))
+
+  (define listen-on-socket-filters
+    (if (opensmtpd-socket-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        (opensmtpd-socket-configuration-filters (opensmtpd-configuration-listen-on-socket record))
+        '()))
+
+  (delete-duplicates
+   (append (remove boolean?
+                   (map-in-order (lambda (listen-on-record) ; get the filters found in the <listen-on-record>s
+                                   (if (and (opensmtpd-interface-filters listen-on-record)
+                                            (= 1 (length (opensmtpd-interface-filters
+                                                          listen-on-record))))
+                                       (car (opensmtpd-interface-filters listen-on-record))
+                                       (opensmtpd-interface-filters listen-on-record)))
+                                 list-of-listen-on-records))
+           listen-on-socket-filters)))
+
+(define (flatten . lst)
+  "Return a list that recursively concatenates all sub-lists of LST."
+  (define (flatten1 head out)
+    (if (list? head)
+        (fold-right flatten1 out head)
+        (cons head out)))
+  (fold-right flatten1 '() lst))
+
+;; This function takes in a record, or list, or anything, and returns
+;; a list of <opensmtpd-table>s assuming the thing you passed into it had
+;; any <opensmtpd-table>s.
+;;
+;; is object record? call func on it's fieldnames
+;; is object list? loop through it's fieldnames calling func on it's records
+;; is object #f or string? or '()? -> #f
+(define (get-opensmtpd-tables value)
+  (delete-duplicates
+   (remove boolean? (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+                     (cond ((opensmtpd-table? value)
+                            value)
+                           ((record? value)
+                            (let* ((record-type (record-type-descriptor value))
+                                   (list-of-record-fieldnames (record-type-fields record-type)))
+                              (map (lambda (fieldname)
+                                     (get-opensmtpd-tables ((record-accessor record-type fieldname) value)))
+                                   list-of-record-fieldnames)))
+                           ((and (list? value) (not (null? value)))
+                            (map get-opensmtpd-tables value))
+                           (else #f))))))
+
+(define (opensmtpd-configuration-fieldname->string record fieldname-accessor record->string)
+  (if (fieldname-accessor record)
+      (begin
+        (string-append
+         (list-of-records->string (fieldname-accessor record) record->string) "\n"))
+      ""))
+
+(define (list-of-records->string list-of-records record->string)
+  (string-append
+   (cond ((not (list? list-of-records))
+          (record->string list-of-records))
+         (else
+          (let loop ([list list-of-records])
+            (if (null? list)
+                ""
+                (string-append
+                 (record->string (car list))
+                 (loop (cdr list)))))))))
+
+(define (opensmtpd-configuration->string record)
+  (string-append
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-bounce
+                                              (lambda (%bounce)
+                                                (if %bounce
+                                                    (list-of-strings->string %bounce)
+                                                    "")))
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-smtp
+                                              opensmtpd-smtp->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-srs
+                                              opensmtpd-configuration-srs->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-queue
+                                              opensmtpd-configuration-queue->string)
+   ;; write out the mta-max-deferred
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-mta-max-deferred
+    (lambda (var)
+      (string-append "mta max-deferred "
+                     (number->string (opensmtpd-configuration-mta-max-deferred record)) "\n")))
+   ;;write out all the tables
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-tables opensmtpd-table->string)
+   ;; write out all the cas
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-cas opensmtpd-ca->string)
+   ;; write out all the pkis
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-pkis opensmtpd-pki->string)
+   ;; write all of the listen-on-records
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-ons
+                                              opensmtpd-interface->string)
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-listen-on-socket
+                                              opensmtpd-socket->string)
+   ;; write all the actions
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-actions
+                                              opensmtpd-action->string)
+   ;; write all of the matches
+   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-matches opensmtpd-match->string)))
+
+;; FIXME/TODO should I use format here srfi-28 ?
+;; web.scm nginx does a (format #f "string" "another string")
+;; this could be a list like (list (file-append opensmtpd-dkimsign "/libexec/filter") "-d gnucode.me -s /path/to/selector.cert")
+;; Then opensmtpd-configuration->mixed-text-file could be rewritten to be something like
+;; (mixed-text-file (eval `(string-append (opensmtpd-configuration-fieldname->string ...)) (gnu services mail)))
+(define (opensmtpd-configuration->mixed-text-file record)
+  ;; should I use this named let, or should I give this a name, or not use it at all...
+  ;; eg: (write-all-fieldnames (list (cons fieldname fieldname->string) (cons fieldname2 fieldname->string)))
+  ;; (let loop ([list (list (cons opensmtpd-configuration-includes (lambda (string)
+  ;;                                                                 (string-append
+  ;;                                                                  "include \"" string "\"\n")))
+  ;;                        (cons opensmtpd-configuration-smtp opensmtpd-smtp->string)
+  ;;                        (cons opensmtpd-configuration-srs opensmtpd-srs->string))])
+  ;;   (if (null? list)
+  ;;       ""
+  ;;       (string-append (opensmtpd-configuration-fieldname->string record
+  ;;                                                                 (caar list)
+  ;;                                                                 (cdar list))
+  ;;                      (loop (cdr list)))))
+
+  (apply mixed-text-file "smtpd.conf"
+         ;; write out the includes
+         (flatten (list
+                   (opensmtpd-configuration-fieldname->string record opensmtpd-configuration-includes
+                                                              opensmtpd-configuration-listen->string)
+                   ;; TODO should I change the below line of code into these two lines of code?
+                   ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-filter-phase->string)
+                   ;;(opensmtpd-configuration-fieldname->string record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
+                   ;; write out all the filters
+                   (opensmtpd-filters->list-of-strings-and-gexps (get-opensmtpd-filters record))
+                   (opensmtpd-configuration->string record)))))
+
+
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "
 listen on lo
@@ -1668,7 +3724,7 @@ (define %default-opensmtpd-config-file
 match from local for any action outbound
 "))
 
-(define opensmtpd-shepherd-service
+(define (opensmtpd-shepherd-service config)
   (match-lambda
     (($ <opensmtpd-configuration> package config-file)
      (list (shepherd-service
@@ -1677,7 +3733,8 @@ (define opensmtpd-shepherd-service
             (documentation "Run the OpenSMTPD daemon.")
             (start (let ((smtpd (file-append package "/sbin/smtpd")))
                      #~(make-forkexec-constructor
-                        (list #$smtpd "-f" #$config-file)
+                        (list #$smtpd "-f" (or #$config-file
+                                               #$(opensmtpd-configuration->mixed-text-file config)))
                         #:pid-file "/var/run/smtpd.pid")))
             (stop #~(make-kill-destructor)))))))
 
@@ -1700,10 +3757,11 @@ (define %opensmtpd-accounts
          (home-directory "/var/empty")
          (shell (file-append shadow "/sbin/nologin")))))
 
-(define opensmtpd-activation
+(define (opensmtpd-activation config)
   (match-lambda
     (($ <opensmtpd-configuration> package config-file)
-     (let ((smtpd (file-append package "/sbin/smtpd")))
+     (let ((smtpd (file-append package "/sbin/smtpd"))
+           (configuration (opensmtpd-configuration->mixed-text-file config)))
        #~(begin
            (use-modules (guix build utils))
            ;; Create mbox and spool directories.
@@ -1711,7 +3769,12 @@ (define opensmtpd-activation
            (mkdir-p "/var/spool/smtpd")
            (chmod "/var/spool/smtpd" #o711)
            (mkdir-p "/var/spool/mail")
-           (chmod "/var/spool/mail" #o711))))))
+           (chmod "/var/spool/mail" #o711)
+           (display (string-append "checking syntax of "
+                                   (or
+                                    #$config-file
+                                    #$configuration)
+                                   "\n")))))))
 
 (define %opensmtpd-pam-services
   (list (unix-pam-service "smtpd")))
diff --git a/gnu/tests/mail.scm b/gnu/tests/mail.scm
index f13751b72f..1bac9f50a2 100644
--- a/gnu/tests/mail.scm
+++ b/gnu/tests/mail.scm
@@ -37,6 +37,7 @@ (define-module (gnu tests mail)
   #:use-module (guix gexp)
   #:use-module (guix store)
   #:use-module (ice-9 ftw)
+  #:use-module (srfi srfi-64)
   #:export (%test-opensmtpd
             %test-exim
             %test-dovecot
@@ -165,6 +166,360 @@ (define %test-opensmtpd
    (description "Send an email to a running OpenSMTPD server.")
    (value (run-opensmtpd-test))))
 
+;; trying to create a bad record, should result in an error.
+;; this function should be able return, instead it should throw an error
+(define (create-bad-record record)
+  ;; TODO why is this not working
+  (with-output-to-port (%make-void-port "w")
+    (lambda () (when record #f))))
+
+;; if this caller function is reached, then trying to create the bad record
+;; resulted in an error.  So return true.
+(define (return-true error arg)
+  #t)
+
+;; two filters with the same name
+(define (bad-interface1)
+  (create-bad-record
+   (opensmtpd-interface
+    (interface "lo")
+    (filters (list
+              (opensmtpd-filter
+               (name "dkimsign")
+               (exec #t)
+               (proc (list (file-append opensmtpd-filter-dkimsign "/libexec/opensmtpd/filter-dkimsign")
+                           " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                           "rando string"
+                           "/etc/dkim/private.key "
+                           "user nobody group nogroup")))
+              (opensmtpd-filter
+               (name "dkimsign")
+               (exec #t)
+               (proc (list (file-append opensmtpd-filter-dkimsign "/libexec/opensmtpd/filter-dkimsign")
+                           " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                           "/etc/dkim/private.key "
+                           "user nobody group nogroup"))))))))
+
+;; duplicate filter names
+(define (bad-interface2)
+  (create-bad-record
+   (opensmtpd-interface
+    (filters (list
+              (opensmtpd-filter-phase
+               (name "src")
+               (phase "connect")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "fcrdns")
+                  (not #t))))
+               (decision "junk"))
+              (opensmtpd-filter-phase
+               (name "src")
+               (phase "helo")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "rdns")
+                  (not #t))))
+               (decision "junk")))))))
+
+ ;; improper phase name
+(define (bad-filter-phase1)
+    (create-bad-record
+     (opensmtpd-filter-phase
+      (name "filter")
+      (phase "wrongString")
+      (decision "bypass")
+      (options
+       (list
+        (opensmtpd-option
+         (option "auth")))))))
+
+;; decision reject requires you to have a
+;; corresponding fieldname 'message' with value of string.
+(define (bad-filter-phase2)
+  (create-bad-record
+   (opensmtpd-interface
+    (filters (list
+              (opensmtpd-filter-phase
+               (name "src")
+               (phase "connect")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "src")
+                  (data (opensmtpd-table
+                         (name "src-table")
+                         (data (list "cat" "hat")))))))
+               (decision "reject")))))))
+
+;; message needs to start with 4xx or 5xx
+(define (bad-filter-phase3)
+  (create-bad-record
+   (opensmtpd-interface
+    (filters (list
+              (opensmtpd-filter-phase
+               (name "src")
+               (phase "connect")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "src")
+                  (data (opensmtpd-table
+                         (name "src-table")
+                         (data (list "cat" "hat")))))))
+               (decision "reject")
+               (message "322 Bad data!")))))))
+
+ ;; there needs to be a value here.  rewrite requires a value!
+(define (bad-filter-phase4)
+  (create-bad-record
+   (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "noFRDNS")
+       (phase "commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns")
+                       (not #t))))
+       (decision "rewrite"))
+      )))))
+
+;; fieldname 'decision' with value "junk" or "bypass", then fieldname 'message' and 'value'
+;; must NOT be defined
+(define (bad-filter-phase5)
+  (create-bad-record
+   (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "noFRDNS")
+       (phase "commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns")
+                       )))
+       (decision "junk")
+       (message "This is not a good email.")))))))
+
+;; you cannot junk on phase commit.  You need to use an eariler phase.
+(define (bad-filter-phase6)
+  (create-bad-record
+   (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "junk-after-commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns"))))
+       (phase "commit")
+       (decision "junk")))))))
+
+;; TODO fix this test
+;; two fcrdns options records
+(define (bad-filter-phase7)
+  (create-bad-record
+   (opensmtpd-filter-phase
+    (name "invalid-fcrdns")
+    (phase "connect")
+    (options
+     (list (opensmtpd-option
+            (option "fcrdns")
+            (not #t))
+           (opensmtpd-option
+            (option "fcrdns")
+            (not #f))))
+    (decision "reject")
+    (message "422 No valid fcrdns."))))
+
+;; option src requires a table
+;; TODO maybe check for other options requiring a table
+(define (bad-filter-phase8)
+  (create-bad-record
+   (opensmtpd-filter-phase
+    (name "filter")
+    (phase "helo")
+    (decision "bypass")
+    (options
+     (list
+      (opensmtpd-option
+       (option "src")))))))
+
+;; option fcrdns cannot have data defined.
+(define (bad-filter-phase9)
+  (create-bad-record
+   (opensmtpd-filter-phase
+    (name "filter")
+    (phase "helo")
+    (decision "bypass")
+    (options
+     (list
+      (opensmtpd-option
+       (option "fcrdns")
+       (data (opensmtpd-table
+               (name "table")
+               (data (list "hello" "cat"))))))))))
+
+
+;; this should be (list ...) instead of '( ...)
+(define (bad-match1)
+  (create-bad-record
+   (opensmtpd-match
+    (options
+     '((opensmtpd-option
+        (option "for any"))))
+    (action
+     (opensmtpd-relay)))))
+
+
+;; duplcate "for" options
+(define (bad-match2)
+  (create-bad-record
+   (opensmtpd-match
+            (options (list
+                      (opensmtpd-option
+                       (option "for any"))
+                      (opensmtpd-option
+                       (option "for local"))))
+            (action
+             (opensmtpd-relay
+              (name "relay"))))))
+
+;; duplicate froms
+(define (bad-match3)
+  (create-bad-record
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "from any"))
+              (opensmtpd-option
+               (option "from auth"))))
+    (action
+     (opensmtpd-relay
+      (name "relay"))))))
+
+;; rcpt-to must have a data field.
+(define (bad-match4)
+  (create-bad-record
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "rcpt-to"))))
+    (action
+     (opensmtpd-relay
+      (name "relay"))))))
+
+;; option 'tls' cannot have fieldname
+;; 'data' defined.
+(define (bad-match5)
+  (create-bad-record
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "tls")
+               (data "hello"))))
+    (action
+     (opensmtpd-relay
+      (name "relay"))))))
+
+;; for any cannot have data
+;; or regex defined
+(define (bad-match6)
+  (create-bad-record
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "for any")
+               (regex #t))))
+    (action
+     (opensmtpd-relay
+      (name "relay"))))))
+
+;; match needs an action
+(define (bad-match7)
+  (create-bad-record
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "from auth")))))))
+
+(define (run-opensmtpd-record-sanitation-test)
+                                        ;(with-output-to-port (%make-void-port "w")
+                                        ;  (lambda ()
+  (test-begin "run-opensmtpd-record-sanitation-test")
+
+  ;; TODO fix me!
+  (test-assert "Test <interface> fieldname 'filters' has two filters with the same name."
+    (catch #t bad-interface1 return-true))
+
+  (test-assert "Test <interface> cannot have two filters with the same name."
+               (catch #t bad-interface2 return-true))
+
+  (test-assert "Test <filter-phase> fieldname 'phase' the right string."
+    (catch #t bad-filter-phase1 return-true))
+
+  (test-assert "Test <filter-phase> fieldname 'decision' w/ value \"reject\" and \"disconnect\" requires a 'message'."
+    (catch #t bad-filter-phase2 return-true))
+
+  (test-assert (string-append  "Test <filter-phase> fieldname 'decision' "
+                               "w/ value \"reject\" and \"disconnect\" requires a 'message'."
+                               " The message must begin with 4xx or 5xx.")
+    (catch #t bad-filter-phase3 return-true))
+
+  (test-assert "Test <filter-phase> fieldname 'rewrite' requires fieldname 'value' to have a number."
+    (catch #t bad-filter-phase4 return-true))
+
+  (test-assert (string-append "Test <filter-phase> fieldname 'decision' with values 'junk' or 'bypass', "
+                             "then fieldname 'message' and 'value' must be blank.")
+    (catch #t bad-filter-phase5 return-true))
+
+  (test-assert "You cannot junk an email on phase commit."
+    (catch #t bad-filter-phase6 return-true))
+
+  ;; TODO fix me!
+  (test-assert "Test <filter-phase> has 2 duplicate options."
+    (catch #t bad-filter-phase7 return-true))
+
+  (test-assert "Test <filter-phase> option 'src' requires a table."
+    (catch #t bad-filter-phase8 return-true))
+
+  ;; TODO fix me!
+  (test-assert "Test <filter-phase> option 'fcrdns' cannot have a table."
+    (catch #t bad-filter-phase9 return-true))
+
+  (test-assert "Test <opensmtpd-match> fieldname 'options' should not be quoted."
+    (catch #t bad-match1 return-true))
+
+  (test-assert "Test <opensmtpd-match> has duplicate 'for' options."
+    (catch #t bad-match2 return-true))
+
+  (test-assert "Test <opensmtpd-match> has duplicate 'from' options."
+    (catch #t bad-match3 return-true))
+
+  (test-assert "Test <opensmtpd-match> option 'rcpt' must have data."
+    (catch #t bad-match4 return-true))
+
+  (test-assert "Test <opensmtpd-match> option 'tls' cannot have fieldname 'data' defined."
+    (catch #t bad-match5 return-true))
+
+  (test-assert "Test <opensmtpd-match> option 'for any' cannot have fieldname 'data' defined."
+    (catch #t bad-match6 return-true))
+
+  (test-assert "Test <opensmtpd-match> needs fieldname 'action' needs to be defined."
+    (catch #t bad-match7 return-true))
+
+  (test-end "run-opensmtpd-record-sanitation-test"))
+
+(define %test-opensmtpd-record-sanitation
+  (system-test
+   (name "opensmtpdRecordSanitation")
+   (description
+    (string-append "<opensmtpd> has numerous sanity checks.\n"
+                   "This checks that invalid configurations, return an\n"
+                   "appropriate error.\n"))
+   (value (run-opensmtpd-record-sanitation-test))))
+
 
 (define %exim-os
   (simple-operating-system

base-commit: 4b3493ed0156709a924f31ef4c9a5efa0815dfe8
-- 
2.38.0





^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [bug#56046] [Patch master v2] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-10-24 17:30 ` [bug#56046] [Patch master v2] services (opensmtpd): " Joshua Branson via Guix-patches via
@ 2022-10-24 18:28   ` Liliana Marie Prikler
  2022-12-23 13:52     ` [bug#56046] [PATCH opensmtpd-records v3] " Joshua Branson via Guix-patches via
  2022-10-24 22:18   ` [bug#56046] [Patch master v2] " jbranso--- via Guix-patches via
  1 sibling, 1 reply; 23+ messages in thread
From: Liliana Marie Prikler @ 2022-10-24 18:28 UTC (permalink / raw)
  To: Joshua Branson, 56046

Am Montag, dem 24.10.2022 um 13:30 -0400 schrieb Joshua Branson:
> This is a V2 patch.  I've added some tests that help test for various
> ways that users could accidentally misconfigure their configuration.
> 
> I probably need to make those error messages, use   
> (guix diagnostics).  Currently compiling the tests, auto runs them.
> So "make" auto runs the tests.  Also their error messages are output
> to the terminal, and I'm not sure how to turn that off.
> 
> tl;dr this is a WIP patch, and I just wanted to submit something,
> because I keep finding more things that I need to fix.
> 
> The task list as always is here:
> https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd.org
>  
> 
> Openmstpd-configuration may only be configured by a config-file that
> uses the smtpd.conf syntax.  This patch, enables one to configure
> opensmtpd by using record types.
> 
> * gnu/services/mail.scm:
> (opensmtpd-table-configuration,
ChangeLog format would be (opensmtpd-table-configuration) followed by a
new line, followed by (opensmtpd-ca-configuration) etc.
> opensmtpd-ca-configuration,
> opensmtpd-pki-configuration,
> opensmtpd-action-local-delivery-configuration,
> opensmtpd-maildir-configuration,
> opensmtpd-mda-configuration,
> opensmtpd-action-relay-configuration,
> opensmtpd-option-configuration,
> opensmtpd-filter-phase-configuration,
> opensmtpd-filter-configuration,
> opensmtpd-interface,
> opensmtpd-socket,
> opensmtpd-match-configuration,
> opensmtpd-smtp-configuration,
> opensmtpd-srs-configuration,
> opensmtpd-queue-configuration, and
> opensmtpd-configuration): New records.
> 
> (false?, is-value-right-type, add-comma-or-string,
> list-of-procedures->string, string-in-list?, my-sanitize,
> opensmtpd-filter-chain?, throw-error-duplicate-option,
> sanitize-list-of-options-for-match-configuration, sanitize-filters,
> list-has-duplicates-or-non-filters?,
> filter-phase-has-message-and-value?,
> filter-phase-decision-lacks-proper-message?,
> filter-phase-lacks-proper-value?,
> filter-phase-has-incorrect-junk-or-bypass?,
> filter-phase-junks-after-commit?,
> list-of-unique-filter-or-filter-phase?, throw-error,
> contains-duplicate?, list-of-type?, list-of-strings?,
> list-of-unique-opensmtpd-option-configuration?,
> list-of-opensmtpd-ca-configuration?,
> list-of-opensmtpd-pki-configuration?,
> list-of-opensmtpd-listen-on-configuration?,
> list-of-unique-opensmtpd-match-configuration?, list-of-strings-
> >string,
> assoc-list? assoc-list, variable->string,
> table-whose-data-are-assoc-list?,
> table-whose-data-are-a-list-of-strings?, assoc-list->string,
> opensmtpd-table-configuration->string,
> opensmtpd-listen-on-configuration->string,
> opensmtpd-listen-on-socket-configuration->string,
> opensmtpd-action-relay-configuration->string,
> opensmtpd-lmtp-configuration->string,
> opensmtpd-mda-configuration->string,
> opensmtpd-maildir-configuration->string,
> opensmtpd-action-local-delivery-configuration->string,
> opensmtpd-action->string, opensmtpd-option-configuration->string,
> opensmtpd-match-configuration->string,
> opensmtpd-ca-configuration->string, opensmtpd-pki-configuration-
> >string,
> generate-filter-chain-name, opensmtpd-filter-chain->string,
> opensmtpd-filter-phase-configuration->string, opensmtpd-filters-
> >string,
> opensmtpd-configuration-listen->string,
> opensmtpd-configuration-srs->string,
> opensmtpd-smtp-configuration->string,
> opensmtpd-configuration-queue->string, get-opensmtpd-actions,
> get-opensmtpd-pki-configurations, get-opensmtpd-filters, flatten,
> get-opensmtpd-tables, opensmtpd-configuration-fieldname->string,
> list-of-records->string, opensmtpd-configuration->mixed-text-file):
> New
> procedures.
> 
> * gnu/tests/mail.scm : new tests for various opensmtpd records.
> 
> * doc/guix.texi (OpenSMTPD Service): Added documentation for the
> new records for opensmtpd.
> ---
>  doc/guix.texi         | 1054 ++++++++++++++++++++-
>  gnu/services/mail.scm | 2085
> ++++++++++++++++++++++++++++++++++++++++-
>  gnu/tests/mail.scm    |  355 +++++++
>  3 files changed, 3475 insertions(+), 19 deletions(-)
> 
> diff --git a/doc/guix.texi b/doc/guix.texi
> index 535c8cdfc3..c80f3e9d76 100644
> --- a/doc/guix.texi
> +++ b/doc/guix.texi
> @@ -25409,14 +25409,59 @@ could instantiate a dovecot service like
> this:
>  @subsubheading OpenSMTPD Service
>  
>  @deffn {Scheme Variable} opensmtpd-service-type
> -This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
> -service, whose value should be an @code{opensmtpd-configuration}
> object
> -as in this example:
> -
> -@lisp
> -(service opensmtpd-service-type
> -         (opensmtpd-configuration
> -           (config-file (local-file "./my-smtpd.conf"))))
> +OpenSMTPD is an easy-to-use mail transfer agent (MTA). Its
> configuration file is
> +throughly documented in @code{man 5 smtpd.conf}. OpenSMTPD
> @strong{listens} for incoming
> +mail and @strong{matches} the mail to @strong{actions}. The
> following records represent those
> +stages:
> +
> +@multitable {aaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @strong{listens}
> +@tab @code{<opensmtpd-interface>}
> +@item
> +@tab @code{<opensmtpd-socket>}
> +@item
> +@tab
> +@item @strong{matches}
> +@tab @code{<opensmtpd-match>}
> +@item
> +@tab
> +@item @strong{actions}
> +@tab @code{<opensmtpd-local-delivery>}
> +@item
> +@tab @code{<opensmtpd-relay>}
> +@end multitable
> +
> +Additionally, each @code{<opensmtpd-interface>} and
> +@code{<opensmtpd-socket>} may use a list of
> +@code{<opensmtpd-filter>}, and/or
> +@code{<opensmtpd-filter-phase>} records to filter email/spam. Also
> +numerous records' fieldnames use @code{<opensmtpd-table>} to hold
> lists
> +or key value pairs of data.
> +
> +A simple example configuration is below:
> +
> +@lisp
> +(let ((smtp.gnu.org (opensmtpd-pki
> +                        (domain "smtp.gnu.org")
> +                        (cert "file.cert")
> +                        (key "file.key"))))
> +  (service opensmtpd-service-type
> +           (opensmtpd-configuration
> +            (listen-ons (list
> +                         (opensmtpd-interface
> +                          (pki smtp.gnu.org))
> +                         (opensmtpd-interface
> +                          (pki smtp.gnu.org)
> +                          (secure-connection "smtps"))))
> +            (matches (list
> +                      (opensmtpd-match
> +                       (action
> +                        (opensmtpd-local-delivery
> +                         (name "local-delivery"))))
> +                      (opensmtpd-match
> +                       (action
> +                        (opensmtpd-relay
> +                         (name "relay")))))))))
>  @end lisp
>  @end deffn
>  
> @@ -25433,14 +25478,1007 @@ it listens on the loopback network
> interface, and allows for mail from
>  users and daemons on the local machine, as well as permitting email
> to
>  remote servers.  Run @command{man smtpd.conf} for more information.
>  
> +<<<<<<< HEAD
You have an artifact here.
> +@item @code{bounce} (default: @code{(list "4h")})
> +
> +@code{bounce} is a list of strings, which send warning messages to
> the envelope
> +sender when temporary delivery failures cause a message to remain in
> the
> +queue for longer than string delay. Each string delay parameter
> consists
> +of a string beginning with a positive decimal integer and a unit
> 's', 'm', 'h',
> +or 'd'. At most four delay parameters can be specified.
> +
> +@item @code{listen-ons} (default: @code{(list (opensmtpd-
> interface))})
> +
> +@code{listen-ons} is a list of @code{<opensmtpd-interface>} records.
> +This list details what interfaces and ports OpenSMTPD listens on as
> well as
> +other information.
> +
> +@item @code{listen-on-socket} (default: @code{(opensmtpd-socket)})
> +
> +Listens for incoming connections on the Unix domain socket.
> +
> +@item @code{includes} (default: @code{#f})
> +
> +@code{includes} is a list of string filenames. Each filename's
> contents is
> +additional configuration that is inserted into the top of the
> configuration
> +file.
> +
> +@item @code{matches} default:
> +
> +@lisp
> +    (list (opensmtpd-match
> +           (action (opensmtpd-local-delivery
> +                    (name "local")
> +                    (method "mbox")))
> +           (for (opensmtpd-option
> +                 (option "for local"))))
> +          (opensmtpd-match
> +           (action (opensmtpd-relay
> +                    (name "outbound")))
> +           (from (opensmtpd-option
> +                  (option "from local")))
> +           (for (opensmtpd-option
> +                 (option "for any")))))
> +@end lisp
> +
> +@code{matches} is a list of @code{<opensmtpd-match>} records, which
> +matches incoming mail and sends it to a correspending action. The
> match
> +records are evaluated sequentially, with the first match winning. If
> an
> +incoming mail does not match any match records, then it is rejected.
> +@c put this backin? @end itemize
> +
> +@c put this back in? @itemize
> +@item @code{mta-max-deferred} (default: @code{100})
> +
> +When delivery to a given host is suspended due to temporary
> failures, cache
> +at most number envelopes for that host such that they can be
> delivered as
> +soon as another delivery succeeds to that host. The default is 100.
> +
> +@item @code{queue} (default: @code{#f})
> +
> +@code{queue} expects an @code{<opensmtpd-queue>} record. With it,
> one may
> +compress and encrypt queue-ed emails as well as set the default
> expiration
> +time for temporarily undeliverable messages.
> +
> +@item @code{smtp} (default: @code{#f})
> +
> +@code{smtp} expects an @code{<opensmtpd-smtp>} record, which lets
> one
> +specifiy how large email may be along with other settings.
> +
> +@item @code{srs} (default: @code{#f})
> +
> +@code{srs} expects an @code{<opensmtpd-srs>} record, which lets one
> set
> +up SRS, the Sender Rewritting Scheme.
> +=======
>  @item @code{setgid-commands?} (default: @code{#t})
>  Make the following commands setgid to @code{smtpq} so they can be
>  executed: @command{smtpctl}, @command{sendmail}, @command{send-
> mail},
>  @command{makemap}, @command{mailq}, and @command{newaliases}.
>  @xref{Setuid Programs}, for more information on setgid programs.
> +>>>>>>> origin/master
>  @end table
>  @end deftp
>  
> +@itemize
> +@item
> +Data Type: opensmtpd-interface
> +
> +Data type representing the configuration of an
> +@code{<opensmtpd-interface>}. Listen on the fieldname
> @code{interface} for
> +incoming connections, using the same syntax as for ifconfig(8). The
> interface
> +parameter may also be an string interface group, an string IP
> address, or a
> +string domain name. Listening can optionally be restricted to a
> specific
> +address fieldname @code{family}, which can be either ``inet4'' or
> ``inet6''.
> +
> +@itemize
> +@item @code{interface} (default: ``lo'')
> +
> +The string interface to listen for incoming connections. These
> interface can
> +usually be found by the command @code{ip link}.
> +
> +@item @code{family} (default: @code{#f})
> +
> +The string IP family to use.  Valid strings are ``inet4'' or
> ``inet6''.
> +
> +@item @code{auth} (default: @code{#f})
> +
> +Support SMTPAUTH: clients may only start SMTP transactions after
> successful
> +authentication. If @code{auth} is @code{#t}, then users are
> authenticated against
> +their own normal login credentials. Alternatively @code{auth} may be
> an
> +@code{<opensmtpd-table>} whose users are authenticated against
> +their passwords.
> +
> +@item @code{auth-optional} (default: @code{#f})
> +
> +Support SMTPAUTH optionally: clients need not authenticate, but may
> do so.
> +This allows the @code{<opensmtpd-interface>} to both accept
> +incoming mail from untrusted senders and permit outgoing mail from
> +authenticated users (using @code{<opensmtpd-match>} fieldname
> +@code{auth}). It can be used in situations where it is not possible
> to listen on
> +a separate port (usually the submission port, 587) for users to
> +authenticate.
> +
> +@item @code{filters} (default: @code{#f})
> +
> +A list of one or many @code{<opensmtpd-filter>} or
> +@code{<opensmtpd-filter-phase>} records. The filters are applied
> +sequentially. These records listen and filter on connections handled
> by this
> +listener.
> +
> +@item @code{hostname} (default: @code{#f})
> +
> +Use string ``hostname'' in the greeting banner instead of the
> default server
> +name.
> +
> +@item @code{hostnames} (default: @code{#f})
> +
> +Override the server name for specific addresses. Use a
> +@code{<opensmtpd-table>} containing a mapping of string IP
> +addresses to hostnames. If the address on which the connection
> arrives
> +appears in the mapping, the associated hostname is used.
> +
> +@item @code{mask-src} (default: @code{#f})
> +
> +If @code{#t}, then omit the from part when prepending “Received”
> headers.
> +
> +@item @code{disable-dsn} (default: @code{#f})
> +
> +When @code{#t}, then disable the DSN (Delivery Status Notification)
> extension.
> +
> +@item @code{pki} (default: @code{#f})
> +
> +For secure connections, use an @code{<opensmtpd-pki>}
> +to prove a mail server's identity.
> +
> +@item @code{port} (default: @code{#f})
> +
> +Listen on the integer port instead of the default port of 25.
> +
> +@item @code{proxy-v2} (default: @code{#f})
> +
> +If @code{#t}, then support the PROXYv2 protocol, rewriting
> appropriately source
> +address received from proxy.
> +
> +@item @code{received-auth} (default: @code{#f})
> +
> +If @code{#t}, then in “Received” headers, report whether the session
> was
> +authenticated and by which local user.
> +
> +@item @code{senders} (default: @code{#f})
> +
> +Look up the authenticated user in the supplied
> +@code{<opensmtpd-table>} to find the email addresses that user is
> +allowed to submit mail as.
> +
> +@item @code{secure-connection} (default: @code{#f})
> +
> +This is a string of one of these options:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item ``smtps''
> +@tab Support SMTPS, by default on port 465.
> +@item ``tls''
> +@tab Support STARTTLS, by default on port 25.
> +@item ``tls-require-verify''
> +@tab Like tls, but force clients to establish
> +@item
> +@tab a secure connection before being allowed to
> +@item
> +@tab start an SMTP transaction.  With the verify
> +@item
> +@tab option, clients must also provide a valid
> +@item
> +@tab certificate to establish an SMTP session.
> +@end multitable
> +
> +@item @code{tag} (default: @code{#f})
> +
> +Clients connecting to the listener are tagged with the given string
> tag.
> +@end itemize
> +
> +@item Data Type: opensmtpd-socket
> +
> +Data type representing the configuration of an
> +@code{<opensmtpd-socket>}. Listen for incoming SMTP
> +connections on the Unix domain socket @samp{/var/run/smtpd.sock}.
> This is done by
> +default, even if the directive is absent.
> +
> +@itemize
> +@item @code{filters} (default: @code{#f})
> +
> +A list of one or many @code{<opensmtpd-filter>} or
> +@code{<opensmtpd-filter-phase>} records. These filter incoming
> +connections handled by this listener.
> +
> +@item @code{mask-src} (default: @code{#f})
> +
> +If @code{#t}, then omit the from part when prepending “Received”
> headers.
> +
> +@item @code{tag} (default: @code{#f})
> +
> +Clients connecting to the listener are tagged with the given string
> tag.
> +@end itemize
> +
> +@item Data Type: opensmtpd-match
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-match>} record.
> +
> +If at least one mail envelope matches the options of one match
> record, receive
> +the incoming message, put a copy into each matching envelope, and
> atomically
> +save the envelopes to the mail spool for later processing by the
> respective
> +@code{<opensmtpd-action>} found in fieldname @code{action}.
> +
> +@itemize
> +@item @code{action} (default: @code{#f})
> +
> +If mail matches this match configuration, then do this action. Valid
> values
> +include @code{<opensmtpd-local-delivery>} or
> +@code{<opensmtpd-relay>}.
> +
> +@item @code{options} (default: @code{#f}) @code{<opensmtpd-option>}
> +The fieldname 'option' is a list of unique
> +@code{<opensmtpd-option>} records.
> +
> +Each @code{<opensmtpd-option>} record's fieldname 'option' has some
> +mutually exclusive options: there can be only one ``for'' and only
> one ``from'' option.
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@headitem for
> +@tab from
> +@item only use one of the following:
> +@tab only use one of the following:
> +@item ``for any''
> +@tab ``from any''
> +@item ``for local''
> +@tab ``from auth''
> +@item ``for domain''
> +@tab ``from local''
> +@item ``for rcpt-to''
> +@tab ``from mail-from''
> +@item
> +@tab ``from socket''
> +@item
> +@tab ``from src''
> +@end multitable
> +
> +The following matching options are supported and can all be negated
> (via not
> +#t). The options that support a table (anything surrounded with '<'
> and '>'
> +eg: <table>), also support specifying regex via (regex #t).
> +
> +@itemize
> +@item @samp{for any}
> +
> +Specify that session may address any destination.
> +
> +@item @samp{for local}
> +
> +Specify that session may address any local domain.  This is the
> default,
> +and may be omitted.
> +
> +@item @samp{for domain _domain_ | <domain>}
> +
> +Specify that session may address the string or list table domain.
> +
> +@item @samp{for rcpt-to _recipient_ | <recipient>}
> +
> +Specify that session may address the string or list table recipient.
> +
> +@item @samp{from any}
> +
> +Specify that session may originate from any source.
> +
> +@item @samp{from auth}
> +
> +Specify that session may originate from any authenticated user, no
> matter
> +the source IP address.
> +
> +@item @samp{from auth _user_ | <user>}
> +
> +Specify that session may originate from authenticated user or user
> list
> +user, no matter the source IP address.
> +
> +@item @samp{from local}
> +
> +Specify that session may only originate from a local IP address, or
> from
> +the local enqueuer.  This is the default, and may be omitted.
> +
> +@item @samp{from mail-from _sender_ | <sender>}
> +
> +Specify that session may originate from sender or table sender, no
> +matter the source IP address.
> +
> +@item @samp{from rdns}
> +
> +Specify that session may only originate from an IP address that
> resolves
> +to a reverse DNS@.
> +
> +@item @samp{from rdns _hostname_ | <hostname>}
> +
> +Specify that session may only originate from an IP address that
> resolves
> +to a reverse DNS matching string or list string hostname.
> +
> +@item @samp{from socket}
> +
> +Specify that session may only originate from the local enqueuer.
> +
> +@item @samp{from src _address_ | <address>}
> +
> +Specify that session may only originate from string or list table
> address
> +which can be a specific address or a subnet expressed in CIDR-
> notation.
> +
> +@item @samp{auth}
> +
> +Matches transactions which have been authenticated.
> +
> +@item @samp{auth _username_ | <username>}
> +
> +Matches transactions which have been authenticated for user or user
> list
> +username.
> +
> +@item @samp{helo _helo-name_ | <helo-name>}
> +
> +Specify that session's HELO / EHLO should match the string or list
> table
> +helo-name.
> +
> +@item @samp{mail-from _sender_ | <sender>}
> +
> +Specify that transactions's MAIL FROM should match the string or
> list
> +table sender.
> +
> +@item @samp{rcpt-to _recipient_ | <recipient>}
> +
> +Specify that transaction's RCPT TO should match the string or list
> table
> +recipient.
> +
> +@item @samp{tag tag}
> +Matches transactions tagged with the given tag.
> +
> +@item @samp{tls}
> +Specify that transaction should take place in a TLS channel.
> +@end itemize
> +
> +Here is a simple example:
> +@lisp
> +    (opensmtpd-option
> +     (not #t)
> +     (regex #f)
> +     (option "for domain")
> +     (data (opensmtpd-table
> +            (name "domain-table")
> +            (data (list "gnu.org" "dismail.de")))))
> +@end lisp
> +
> +The mail must NOT come from the domains @samp{gnu.org} or
> @samp{dismail.de}.
> +
> +@item Data Type: opensmtpd-option
> +@end itemize
> +
> +@item Data Type: opensmtpd-local-delivery
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-local-delivery>} record.
> +
> +@itemize
> +@item
> +@code{name} (default: @code{#f})
> +
> +@code{name} is the string name of the relay action.
> +
> +@item @code{method} (default: @code{"mbox"})
> +
> +The email delivery option.  Valid options are:
> +
> +@itemize
> +@item @code{"mbox"}
> +
> +Deliver the message to the user's mbox with mail.local(8).
> +
> +@item @code{"expand-only"}
> +
> +Only accept the message if a delivery method was specified in an
> aliases
> +or .forward file.
> +
> +@item @code{"forward-only"}
> +
> +Only accept the message if the recipient results in a remote address
> after
> +the processing of aliases or forward file.
> +
> +@item @code{<opensmtpd-lmtp>}
> +
> +Deliver the message to an LMTP server at
> +@code{<opensmtpd-lmtp>}'s fieldname @code{destination}. The location
> +may be expressed as string host:port or as a UNIX socket.
> Optionally,
> +@code{<opensmtpd-lmtponfiguration>}'s fieldname @code{rcpt-to} might
> be specified
> +to use the recipient email address (after expansion) instead of the
> local
> +user in the LMTP session as RCPT TO@.
> +
> +@item @code{<opensmtpd-maildir>}
> +
> +Deliver the message to the maildir in
> +@code{<opensmtpd-maildir>}'s fieldname @code{pathname} if specified,
> +or by default to @samp{~/Maildir}.
> +
> +The pathname may contain format specifiers that are expanded before
> use
> +(see the below section about Format Specifiers).
> +
> +If @code{<opensmtpd-maildir>}'s record fieldname @code{junk} is
> @code{#t},
> +then message will be moved to the ‘Junk’ folder if it contains a
> positive
> +‘X-Spam’ header. This folder will be created under fieldname
> @code{pathname} if
> +it does not yet exist.
> +
> +@item @code{<opensmtpd-mda>}
> +
> +Delegate the delivery to the @code{<opensmtpd-mda>}'s fieldname
> +@code{command} (type string) that receives the message on its
> standard input.
> +
> +The @code{command} may contain format specifiers that are expanded
> before use
> +(see Format Specifiers).
> +@end itemize
> +
> +@item @code{alias} (default: @code{#f})
> +
> +Use the mapping table for aliases expansion. @code{alias} is an
> +@code{<opensmtpd-table>}.
> +
> +@item @code{ttl} (default: @code{#f})
> +
> +@code{ttl} is a string specify how long a message may remain in the
> queue.  It's
> +format is @samp{n@{s|m|h|d@}}.  eg: ``4m'' is four minutes.
> +
> +@item @code{user} (default: @code{#f} )
> +
> +@code{user} is the string username for performing the delivery, to
> be looked up
> +with getpwnam(3).
> +
> +This is used for virtual hosting where a single username is in
> charge of
> +handling delivery for all virtual users.
> +
> +This option is not usable with the mbox delivery method.
> +
> +@item @code{userbase} (default: @code{#f})
> +
> +@code{userbase} is an @code{<opensmtpd-table>} record for mapping
> user
> +lookups instead of the getpwnam(3) function.
> +
> +The fieldnames @code{user} and @code{userbase} are mutually
> exclusive.
> +
> +@item @code{virtual} (default: @code{#f})
> +
> +@code{virtual} is an @code{<opensmtpd-table>} record is used for
> virtual
> +expansion.
> +@end itemize
> +
> +@item Data Type: opensmtpd-relay
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-relay>} record.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +
> +@code{name} is the string name of the relay action.
> +
> +@item @code{backup} (default: @code{#f})
> +
> +When @code{#t}, operate as a backup mail exchanger delivering
> messages to any
> +mail exchanger with higher priority.
> +
> +@item @code{backup-mx} (default: @code{#f})
> +
> +Operate as a backup mail exchanger delivering messages to any mail
> exchanger
> +with higher priority than mail exchanger identified as string name.
> +
> +@item @code{helo} (default: @code{#f})
> +
> +Advertise string heloname as the hostname to other mail exchangers
> during
> +the HELO phase.
> +
> +@item @code{helo-src} (default: @code{#f} )
> +
> + Use the mapping @code{<opensmtpd-table>} to look up a hostname
> +matching the source address, to advertise during the HELO phase.
> +
> +@item @code{domain} (default: @code{#f})
> +
> +Do not perform MX lookups but look up destination domain in an
> +@code{<opensmtpd-table>} and use matching relay url as relay host.
> +
> +@item @code{host} (default: @code{#f})
> +
> +Do not perform MX lookups but relay messages to the relay host
> described by
> +the string relay-url. The format for relay-url is
> +@samp{[proto://[label@@]]host[:port]}. The following protocols are
> available:
> +
> +@multitable {aaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item smtp
> +@tab Normal SMTP session with opportunistic STARTTLS (the default).
> +@item smtp+tls
> +@tab Normal SMTP session with mandatory STARTTLS@.
> +@item smtp+notls
> +@tab Plain text SMTP session without TLS@.
> +@item lmtp
> +@tab LMTP session.  port is required.
> +@item smtps
> +@tab SMTP session with forced TLS on connection, default port is
> +@item
> +@tab 465.
> +@end multitable
> +
> +Unless noted, port defaults to 25.
> +
> +The label corresponds to an entry in a credentials table, as
> documented in
> +@samp{table(5)}. It is used with the @samp{"smtp+tls"} and
> @samp{"smtps"} protocols for
> +authentication. Server certificates for those protocols are verified
> by
> +default.
> +
> +@item @code{pki} (default: @code{#f})
> +
> +For secure connections, use the certificate associated with
> +@code{<opensmtpd-pki>} (declared in a pki directive) to prove the
> +client's identity to the remote mail server.
> +
> +@item @code{srs} (default: @code{#f})
> +
> +If @code{#t}, then when relaying a mail resulting from a forward,
> use the Sender
> +Rewriting Scheme to rewrite sender address.
> +
> +@item @code{tls} (default: @code{#f}) boolean or string ``no-
> verify''
> +
> +When @code{#t}, Require TLS to be used when relaying, using
> mandatory STARTTLS by
> +default. When used with a smarthost, the protocol must not be
> +@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not
> require a valid
> +certificate.
> +
> +@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table>}
> +
> +Use the alist @code{<opensmtpd-table>} for connecting to relay-url
> +using credentials. This option is usable only with fieldname
> @code{host} option.
> +
> +@item @code{mail-from} (default: @code{#f}) string
> +
> +Use the string mailaddress as MAIL FROM address within the SMTP
> transaction.
> +
> +@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-
> table>}
> +
> +Use the string or @code{<opensmtpd-table>} sourceaddr for the
> +source IP address, which is useful on machines with multiple
> interfaces. If
> +the list contains more than one address, all of them are used in
> such a way
> +that traffic is routed as efficiently as possible.
> +@end itemize
> +
> +@item Data Type: opensmtpd-filter
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-filter>}. This is the filter record one should use
> +if they want to use an external package to filter email eg: rspamd
> or
> +spamassassin.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +
> +The string name of the filter.
> +
> +@item @code{proc} (default: @code{#f})
> +
> +The string command or process name.  If @code{proc-exec} is
> @code{#t}, @code{proc} is
> +treated as a command to execute.  Otherwise, it is a process name.
> +
> +@item @code{proc-exec} (default: @code{#f})
> +@end itemize
> +
> +@item Data Type: opensmtpd-filter-phase
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-filter-phase>}.
> +
> +In a regular workflow, smtpd(8) may accept or reject a message based
> only on
> +the content of envelopes. Its decisions are about the handling of
> the message,
> +not about the handling of an active session.
> +
> +Filtering extends the decision making process by allowing smtpd(8)
> to stop at
> +each phase of an SMTP session, check that options are met, then
> decide if a
> +session is allowed to move forward.
> +
> +With filtering via an @code{<opensmtpd-filter-phase>} record, a
> +session may be interrupted at any phase before an envelope is
> complete. A
> +message may also be rejected after being submitted, regardless of
> whether the
> +envelope was accepted or not.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +
> +The string name of the filter phase.
> +
> +@item @code{phase-name} (default: @code{#f})
> +
> +The string name of the phase. Valid values are:
> +
> +@multitable {aaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item ``connect''
> +@tab upon connection, before a banner is displayed
> +@item ``helo''
> +@tab after HELO command is submitted
> +@item ``ehlo''
> +@tab after EHLO command is submitted
> +@item ``mail-from''
> +@tab after MAIL FROM command is submitted
> +@item ``rcpt-to''
> +@tab after RCPT TO command is submitted
> +@item ``data''
> +@tab after DATA command is submitted
> +@item ``commit''
> +@tab after message is fully is submitted
> +@end multitable
> +
> +@item @code{options} (default @code{#f})
> +
> +A list of unique @code{<opensmtpd-option>} records.
> +
> +At each phase, various options, specified by a list of
> +@code{<opensmtpd-option>}, may be checked. The
> +@code{<opensmtpd-option>}'s fieldname 'option' values of:
> ``fcrdns'',
> +``rdns'', and ``src'' data are available in all phases, but other
> data must have
> +been already submitted before they are available. Options with a
> @samp{<table>}
> +next to them require the @code{<opensmtpd-option>}'s fieldname
> +@code{data} to be an @code{<opensmtpd-table>}. There are the
> available
> +options:
> +
> +@multitable {aaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item fcrdns
> +@tab forward-confirmed reverse DNS is valid
> +@item rdns
> +@tab session has a reverse DNS
> +@item rdns <table>
> +@tab session has a reverse DNS in table
> +@item src <table>
> +@tab source address is in table
> +@item helo <table>
> +@tab helo name is in table
> +@item auth
> +@tab session is authenticated
> +@item auth <table>
> +@tab session username is in table
> +@item mail-from <table>
> +@tab sender address is in table
> +@item rcpt-to <table>
> +@tab recipient address is in table
> +@end multitable
> +
> +These conditions may all be negated by setting
> +@code{<opensmtpd-option>}'s fieldname @code{not} to @code{#t}.
> +
> +Any conditions that require a table may indicate that tables include
> regexs
> +setting @code{<opensmtpd-option>}'s fieldname @code{regex} to
> @code{#t}.
> +
> +@item @code{decision}
> +
> +A string decision to be taken. Some decisions require an
> @code{message} or
> +@code{value}. Valid strings are:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item ``bypass''
> +@tab the session or transaction bypasses filters
> +@item ``disconnect'' message
> +@tab the session is disconnected with message
> +@item ``junk''
> +@tab the session or transaction is junked, i.e., an
> +@item
> +@tab ‘X-Spam: yes’ header is added to any messages
> +@item ``reject'' message
> +@tab the command is rejected with message
> +@item ``rewrite'' value
> +@tab the command parameter is rewritten with value
> +@end multitable
> +
> +Decisions that involve a message require that the message be RFC
> valid,
> +meaning that they should either start with a 4xx or 5xx status code.
> +Descisions can be taken at any phase, though junking can only happen
> before
> +a message is committed.
> +
> +@item @code{message} (default @code{#f})
> +
> +A string message beginning with a 4xx or 5xx status code.
> +
> +@item @code{value} (default: @code{#f})
> +
> +A number value.  @code{value} and @code{message} are mutually
> exclusive.
> +@end itemize
> +
> +@item Data Type: opensmtpd-option
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-option>}, which is used by
> +@code{<opensmtpd-filter-phase>} and @code{<opensmtpd-match>}
> +to match various options for email.
> +
> +@itemize
> +@item @code{conditition} (default @code{#f})
> +
> +A string option to be taken. Some options require a string or an
> +@code{<opensmtpd-table>} via the fieldname data. When the option
> +record is used inside of an @code{<opensmtpd-filter-phase>}, then
> +valid strings are:
> +
> +At each phase, various options may be matched. The fcrdns, rdns, and
> src
> +data are available in all phases, but other data must have been
> already
> +submitted before they are available.
> +
> +@multitable {aaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item ``fcrdns''
> +@tab forward-confirmed reverse DNS is valid
> +@item ``rdns''
> +@tab session has a reverse DNS
> +@item ``rdns'' <table>
> +@tab session has a reverse DNS in table
> +@item ``src'' <table>
> +@tab source address is in table
> +@item ``helo'' <table>
> +@tab helo name is in table
> +@item ``auth''
> +@tab session is authenticated
> +@item ``auth'' <table>
> +@tab session username is in table
> +@item ``mail-from'' <table>
> +@tab sender address is in table
> +@item ``rcpt-to'' <table>
> +@tab recipient address is in table
> +@end multitable
> +
> +When @code{<opensmtpd-option>} is used inside of an
> +@code{<opensmtpd-match>}, then valid strigs for fieldname
> @code{option}
> +are: ``for'', ``for any'', ``for local'', ``for domain'', ``for
> rcpt-to'', ``from any''
> +``from auth'', ``from local'', ``from mail-from'', ``from rdns'',
> ``from socket'',
> +``from src'', ``auth'', ``helo'', ``mail-from'', ``rcpt-to'',
> ``tag'', or ``tls''.
> +
> +@item @code{data} (default @code{#f}) @code{<opensmtpd-table>}
> +
> +Some options require a table to be present. One would specify that
> table
> +here.
> +@item @code{regex} (default: @code{#f}) boolean
> +
> +Any options using a table may indicate that tables hold regex by
> +prefixing the table name with the keyword regex.
> +
> +@item @code{not} (default: @code{#f}) boolean
> +
> +When @code{#t}, this option record is negated.
> +@end itemize
> +
> +@item Data Type: opensmtpd-table
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-table>}.
> +
> +@itemize
> +@item @code{name} (default @code{#f})
> +
> +@code{name} is the name of the @code{<opensmtpd-table>} record.
> +
> +@item @code{data} (default: @code{#f})
> +
> +@code{data} expects a list of strings or an alist, which is a list
> of
> +cons cells.  eg: @code{(data (list ("james" . "password")))} OR
> +@code{(data (list ("gnu.org" "fsf.org")))}.
> +@end itemize
> +
> +@item Data Type: opensmtpd-pki
> +
> +This data type represents the configuration of an
> +@code{<opensmtpd-pki>}.
> +
> +@itemize
> +@item @code{domain} (default @code{#f})
> +
> +@code{domain} is the string name of the @code{<opensmtpd-pki>}
> record.
> +
> +@item @code{cert} (default: @code{#f})
> +
> +@code{cert} (default: @code{#f})
> +
> +@code{cert} is the string certificate filename to use for this pki.
> +
> +@item @code{key} (default: @code{#f})
> +
> +@code{key} is the string certificate falename to use for this pki.
> +
> +@item @code{dhe} (default: @code{"none"})
> +
> +Specify the DHE string parameter to use for DHE cipher suites with
> host
> +pkiname. Valid parameter values are ``none'', ``legacy'', or
> ``auto''. For ``legacy'', a
> +fixed key length of 1024 bits is used, whereas for ``auto'', the key
> length is
> +determined automatically. The default is ``none'', which disables
> DHE cipher
> +suites.
> +@end itemize
> +
> +@item Data Type: opensmtpd-maildir
> +
> +@itemize
> +@item @code{pathname} (default: @code{"~/Maildir"})
> +
> +Deliver the message to the maildir if pathname if specified, or by
> default
> +to @samp{~/Maildir}.
> +
> +The pathname may contain format specifiers that are expanded before
> use
> +(see FORMAT SPECIFIERS).
> +
> +@item @code{junk} (default: @code{#f})
> +
> +If the junk argument is @code{#t}, then the message will be moved to
> the @samp{‘Junk’}
> +folder if it contains a positive @samp{‘X-Spam’} header. This folder
> will be
> +created under pathname if it does not yet exist.
> +@end itemize
> +
> +@item Data Type: opensmtpd-mda
> +
> +@itemize
> +@item @code{name}
> +
> +The string name for this MDA command.
> +
> +@item @code{command}
> +
> +Delegate the delivery to a command that receives the message on its
> standard
> +input.
> +
> +The command may contain format specifiers that are expanded before
> use (see
> +FORMAT SPECIFIERS).
> +@end itemize
> +
> +@item Data Type: opensmtpd-queue
> +
> +@itemize
> +@item @code{compression} (default @code{#f})
> +
> +Store queue files in a compressed format. This may be useful to save
> disk
> +space.
> +
> +@item @code{encryption} (default @code{#f})
> +
> +Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If
> no key is specified, it is
> +read with getpass(3). If the string stdin or a single dash (‘-’) is
> given
> +instead of a key, the key is read from the standard input.
> +
> +@item @code{ttl-delay} (default @code{#f})
> +
> +Set the default expiration time for temporarily undeliverable
> messages,
> +given as a positive decimal integer followed by a unit s, m, h, or
> d. The
> +default is four days (``4d'').
> +@end itemize
> +
> +@item Data Type: opensmtpd-smtp
> +
> +Data type representing an @code{<opensmtpd-smtp>} record.
> +
> +@itemize
> +@item @code{ciphers} (default: @code{#f})
> +
> +Set the control string for
> SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default
> is
> +         ``HIGH:!aNULL:!MD5''.
> +
> +@item @code{limit-max-mails} (default: @code{100})
> +
> +Limit the number of messages to count for each sessio
> +
> +@item @code{limit-max-rcpt} (default: @code{1000})
> +
> +Limit the number of recipients to count for each transaction.
> +
> +@item @code{max-message-size} (default: @code{35M})
> +
> +Reject messages larger than size, given as a positive number of
> bytes or as
> +a string to be parsed with scan@math{_scaled}(3).
> +
> +@item @code{sub-addr-delim character} (default: @code{+})
> +
> +When resolving the local part of a local email address, ignore the
> ASCII
> +character and all characters following it. This is helpful for email
> +filters. @samp{"admin+bills@@gnu.org"} is the same email address as
> +@samp{"admin@@gnu.org"}. BUT an email filter can filter emails
> addressed to first
> +email address into a 'Bills' email folder.
> +@end itemize
> +
> +@item Data Type: opensmtpd-srs
> +
> +@itemize
> +@item @code{key} (default: @code{#f})
> +
> +Set the secret key to use for SRS, the Sender Rewriting Scheme.
> +
> +@item @code{backup-key} (default: @code{#f})
> +
> +Set a backup secret key to use as a fallback for SRS@. This can be
> used to
> +implement SRS key rotation.
> +
> +@item @code{ttl-delay} (default: @code{"4d"})
> +
> +Set the time-to-live delay for SRS envelopes. After this delay, a
> bounce
> +reply to the SRS address will be discarded to limit risks of forged
> +addresses.
> +@end itemize
> +
> +@item Format Specifiers
> +
> +Some configuration records support expansion of their parameters at
> +runtime. Such records (for example
> +@code{<opensmtpd-maildir>}, @code{<opensmtpd-mda>}) may use
> +format specifiers which are expanded before delivery or relaying.
> The
> +following formats are currently supported:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{sender@}}
> +@tab sender email address, may be empty string
> +@item @samp{%@{sender.user@}}
> +@tab user part of the sender email address, may be empty
> +@item @samp{%@{sender.domain@}}
> +@tab domain part of the sender email address, may be empty
> +@item @samp{%@{rcpt@}}
> +@tab recipient email address
> +@item @samp{%@{rcpt.user@}}
> +@tab user part of the recipient email address
> +@item @samp{%@{rcpt.domain@}}
> +@tab domain part of the recipient email address
> +@item @samp{%@{dest@}}
> +@tab recipient email address after expansion
> +@item @samp{%@{dest.user@}}
> +@tab user part after expansion
> +@item @samp{%@{dest.domain@}}
> +@tab domain part after expansion
> +@item @samp{%@{user.username@}}
> +@tab local user
> +@item @samp{%@{user.directory@}}
> +@tab home directory of the local user
> +@item @samp{%@{mbox.from@}}
> +@tab name used in mbox From separator lines
> +@item @samp{%@{mda@}}
> +@tab mda command, only available for mda wrappers
> +@end multitable
> +
> +Expansion formats also support partial expansion using the optional
> bracket notations
> +with substring offset.  For example, with recipient domain
> @samp{“example.org”}:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{rcpt.domain[0]@}}
> +@tab expands to “e”
> +@item @samp{%@{rcpt.domain[1]@}}
> +@tab expands to “x”
> +@item @samp{%@{rcpt.domain[8:]@}}
> +@tab expands to “org”
> +@item @samp{%@{rcpt.domain[-3:]@}}
> +@tab expands to “org”
> +@item @samp{%@{rcpt.domain[0:6]@}}
> +@tab expands to “example”
> +@item @samp{%@{rcpt.domain[0:-4]@}}
> +@tab expands to “example”
> +@end multitable
> +
> +In addition, modifiers may be applied to the token.  For example,
> with recipient
> +@samp{“User+Tag@@Example.org”}:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{rcpt:lowercase@}}
> +@tab expands to “user+tag@@example.org”
> +@item @samp{%@{rcpt:uppercase@}}
> +@tab expands to “USER+TAG@@EXAMPLE.ORG”
> +@item @samp{%@{rcpt:strip@}}
> +@tab expands to “User@@Example.org”
> +@item @samp{%@{rcpt:lowercasestrip@}}
> +@tab expands to “user@@example.org”
> +@end multitable
> +
> +For security concerns, expanded values are sanitized and potentially
> dangerous
> +characters are replaced with ‘:’. In situations where they are
> desirable, the
> +“raw” modifier may be applied. For example, with recipient
> +@samp{“user+t?g@@example.org”}:
> +
> +@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{rcpt@}}
> +@tab expands to “user+t:g@@example.org”
> +@item @samp{%@{rcpt:raw@}}
> +@tab expands to “user+t?g@@example.org”
> +@end multitable
> +@end itemize
> +
>  @subsubheading Exim Service
>  
>  @cindex mail transfer agent (MTA)
> diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
> index 43f144a42d..d86e083d19 100644
> --- a/gnu/services/mail.scm
> +++ b/gnu/services/mail.scm
> @@ -58,10 +58,146 @@ (define-module (gnu services mail)
>              mailbox-configuration
>              namespace-configuration
>  
> +            opensmtpd-table
> +            opensmtpd-table?
> +            opensmtpd-table-name
> +            opensmtpd-table-file-db
> +            opensmtpd-table-data
> +
> +            opensmtpd-ca
> +            opensmtpd-ca?
> +            opensmtpd-ca-name
> +            opensmtpd-ca-file
> +
> +            opensmtpd-pki
> +            opensmtpd-pki?
> +            opensmtpd-pki-domain
> +            opensmtpd-pki-cert
> +            opensmtpd-pki-key
> +            opensmtpd-pki-dhe
> +
> +            opensmtpd-local-delivery
> +            opensmtpd-local-delivery?
> +            opensmtpd-local-delivery-method
> +            opensmtpd-local-delivery-alias
> +            opensmtpd-local-delivery-ttl
> +            opensmtpd-local-delivery-user
> +            opensmtpd-local-delivery-userbase
> +            opensmtpd-local-delivery-virtual
> +            opensmtpd-local-delivery-wrapper
> +
> +            opensmtpd-maildir
> +            opensmtpd-maildir?
> +            opensmtpd-maildir-pathname
> +            opensmtpd-maildir-junk
> +
> +            opensmtpd-mda
> +            opensmtpd-mda-name
> +            opensmtpd-mda-command
> +
> +            opensmtpd-lmtp
> +            opensmtpd-lmtp-destination
> +            opensmtpd-lmtp-rcpt
> +
> +            opensmtpd-relay
> +            opensmtpd-relay?
> +            opensmtpd-relay-backup
> +            opensmtpd-relay-backup-mx
> +            opensmtpd-relay-helo
> +            opensmtpd-relay-domain
> +            opensmtpd-relay-host
> +            opensmtpd-relay-pki
> +            opensmtpd-relay-srs
> +            opensmtpd-relay-tls
> +            opensmtpd-relay-auth
> +            opensmtpd-relay-mail-from
> +            opensmtpd-relay-src
> +
> +            opensmtpd-option
> +            opensmtpd-option?
> +            opensmtpd-option-option
> +            opensmtpd-option-not
> +            opensmtpd-option-regex
> +            opensmtpd-option-data
> +
> +            opensmtpd-filter-phase
> +            opensmtpd-filter-phase?
> +            opensmtpd-filter-phase-name
> +            opensmtpd-filter-phase-phase-name
> +            opensmtpd-filter-phase-options
> +            opensmtpd-filter-phase-decision
> +            opensmtpd-filter-phase-message
> +            opensmtpd-filter-phase-value
> +
> +            opensmtpd-filter
> +            opensmtpd-filter?
> +            opensmtpd-filter-name
> +            opensmtpd-filter-proc
> +
> +            opensmtpd-interface
> +            opensmtpd-interface?
> +            opensmtpd-interface-interface
> +            opensmtpd-interface-family
> +            opensmtpd-interface-auth
> +            opensmtpd-interface-auth-optional
> +            opensmtpd-interface-filters
> +            opensmtpd-interface-hostname
> +            opensmtpd-interface-hostnames
> +            opensmtpd-interface-mask-src
> +            opensmtpd-interface-disable-dsn
> +            opensmtpd-interface-pki
> +            opensmtpd-interface-port
> +            opensmtpd-interface-proxy-v2
> +            opensmtpd-interface-received-auth
> +            opensmtpd-interface-senders
> +            opensmtpd-interface-secure-connection
> +            opensmtpd-interface-tag
> +
> +            opensmtpd-socket
> +            opensmtpd-socket?
> +            opensmtpd-socket-filters
> +            opensmtpd-socket-mask-src
> +            opensmtpd-socket-tag
> +
> +            opensmtpd-match
> +            opensmtpd-match?
> +            opensmtpd-match-action
> +            opensmtpd-match-options
> +
> +            opensmtpd-smtp
> +            opensmtpd-smtp?
> +            opensmtpd-smtp-ciphers
> +            opensmtpd-smtp-limit-max-mails
> +            opensmtpd-smtp-limit-max-rcpt
> +            opensmtpd-smtp-max-message-size
> +            opensmtpd-smtp-sub-addr-delim character
> +
> +            opensmtpd-srs
> +            opensmtpd-srs?
> +            opensmtpd-srs-key
> +            opensmtpd-srs-backup-key
> +            opensmtpd-srs-ttl-delay
> +
> +            opensmtpd-queue
> +            opensmtpd-queue?
> +            opensmtpd-queue-compression
> +            opensmtpd-queue-encryption
> +            opensmtpd-queue-ttl-delay
> +
>              opensmtpd-configuration
>              opensmtpd-configuration?
> -            opensmtpd-service-type
> -            %default-opensmtpd-config-file
> +            opensmtpd-package
> +            opensmtpd-config-file
> +            opensmtpd-configuration-bounce
> +            opensmtpd-configuration-listen-ons
> +            opensmtpd-configuration-listen-on-socket
> +            opensmtpd-configuration-includes
> +            opensmtpd-configuration-matches
> +            opensmtpd-configuration-mda-wrappers
> +            opensmtpd-configuration-mta-max-deferred
> +            opensmtpd-configuration-srs
> +            opensmtpd-configuration-smtp
> +            opensmtpd-configuration-queue
>  
>              mail-aliases-service-type
>  
> @@ -1641,22 +1777,1942 @@ (define (generate-dovecot-documentation)
>         (listeners unix-listener-configuration fifo-listener-
> configuration
>                    inet-listener-configuration))
>        (protocol-configuration ,protocol-configuration-fields))
> -  'dovecot-configuration))
> +   'dovecot-configuration))
>  
>  \f
>  ;;;
>  ;;; OpenSMTPD.
>  ;;;
>  
> +;; file-exists? is in the guile standard library.  BUT I errors if
> its arg
> +;; is a list.  eg:  (file-exists? (list "hello" "hello"))
> +;; TODO I need to find a way to remove this definition and rewrite
> my code.
> +(define (file-exists? file)
> +  (if (string? file)
> +      (access? file F_OK)
> +      #f))
> +
> +;; some fieldnames have a default value of #f, which is ok.  They
> cannot have a value of #t.
> +;; for example opensmtpd-table-data can be #f, BUT NOT true.
> +;; my/sanitize procedure tests values to see if they are of the
> right kind.
> +;; procedure false? is needed to allow fields like 'values' to be
> blank, (empty), or #f BUT also
> +;; have a value like a list of strings.
> +(define (false? var)
> +  (eq? #f var))
> +
> +;; this procedure takes in a var and a list of procedures.  It loops
> through list of procedures passing in var to each.
> +;; if one procedure returns #t, the function returns true. 
> Otherwise #f.
> +;; TODO for fun rewrite this using map
> +;; If I rewrote it in map, then it may help with sanitizing.
> +;; eg: I could then potentially easily sanitize vars with lambda
> procedures.
> +(define (is-value-right-type? var list-of-procedures record
> fieldname)
> +  (if (null? list-of-procedures)
> +      #f
> +      (if ((car list-of-procedures) var)
> +          #t
> +          (is-value-right-type? var (cdr list-of-procedures) record
> fieldname))))
> +
> +;; converts strings like this:
> +;; "apple, ham, cherry" -> "apple, ham, or cherry"
> +;; "pineapple" -> "pinneapple".
> +;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
> +(define (add-comma-or string)
> +  (define last-comma-location (string-rindex string #\,))
> +  (if last-comma-location
> +      (if (string-contains string ", or" last-comma-location)
> +          string
> +          (string-replace string ", or" last-comma-location
> +                          (+ 1 last-comma-location)))
> +      string))
> +
> +(define (list-of-procedures->string procedures)
> +  (define string
> +    (let loop ((procedures procedures))
> +      (if (null? procedures)
> +          ""
> +          (begin
> +            (string-append
> +             (cond ((eq? false? (car procedures))
> +                    "#f , ")
> +                   ((eq? boolean? (car procedures))
> +                    "boolean, ")
> +                   ((eq? string? (car procedures))
> +                    "string, ")
> +                   ((eq? integer? (car procedures))
> +                    "integer, ")
> +                   ((eq? list-of-strings? (car procedures))
> +                    "list of strings, ")
> +                   ((eq? assoc-list? (car procedures))
> +                    "an association list, ")
> +                   ((eq? opensmtpd-pki? (car procedures))
> +                    "an <opensmtpd-pki> record, ")
> +                   ((eq? opensmtpd-table? (car procedures))
> +                    "an <opensmtpd-table> record, ")
> +                   ((eq? list-of-unique-opensmtpd-match? (car
> procedures))
> +                    "a list of unique <opensmtpd-match> records, ")
> +                   ((eq? list-of-strings-or-gexps? (car procedures))
> +                    "a list of strings or gexps, ")
> +                   ((eq? table-whose-data-are-assoc-list? (car
> procedures))
> +                    (string-append
> +                     "an <opensmtpd-table> record whose fieldname
> 'data' are an assoc-list \n"
> +                     "(eg: (opensmtpd-table (name \"hostnames\")
> (data '((\"124.394.23.1\" . \"gnu.org\"))))), "))
> +                   ((eq? file-exists? (car procedures))
> +                    "file, ")
> +                   (else "has an incorrect value, "))
> +             (loop (cdr procedures)))))))
> +  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
> +
> +(define (string-in-list? string list)
> +  (member string list))
> +
> +(define (list-of-strings-or-gexps? list)
> +  (and (list? list)
> +       (cond ((null? list)
> +              #t)
> +             ((or (string? (car list))
> +                  (gexp? (car list))
> +                  (local-file? (car list))
> +                  (file-append? (car list))
> +                  (plain-file? (car list))
> +                  (computed-file? (car list))
> +                  (program-file? (car list)))
> +              (list-of-strings-or-gexps? (cdr list)))
> +             (else #f))))
> +
> +(define (my/sanitize var record fieldname list-of-procedures)
> +  (if (is-value-right-type? var list-of-procedures record fieldname)
> +      var
> +      (begin
> +        (display (string-append "<" record "> fieldname: '"
> fieldname "' is of type "
> +                                (list-of-procedures->string list-of-
> procedures) "\n"))
> +        (throw 'bad! var))))
That's a rather crude way of sanitizing.  You should probably raise a
formatted-message or similar.  I'd also curry this as follows:

(define (((expect-any predicates) record field) var)
  (if (any (cute <> var) predicates)
      var
      (do-the-exception-raising)))

where do-the-exception-raising contains all the formatting stuff etc.
that I skipped for the sake of simplicity.

Then you can define (expect-string-or-#f) and whatever else you need
quite simply.

> +;; Some example opensmtpd-tables:
> +;;
> +;;  (opensmtpd-table (name "root accounts") (data '(("joshua" .
> "root@dismail.de") ("joshua" . "postmaster@dismail.de"))))
> +;;  (opensmtpd-table (name "root accounts") (data (list "mysite.me"
> "your-site.com")))
> +;;  TODO should <opensmtpd-table> support have a fieldname 'file'?
> +;;  Or should I change name to name-or-file ?
> +(define-record-type* <opensmtpd-table>
> +  opensmtpd-table make-opensmtpd-table
> +  opensmtpd-table?
> +  this-record
> +  (name opensmtpd-table-name ;; string
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-table" "name" (list
> string?)))))
> +  (file-db opensmtpd-table-file-db
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-table" "file-db"
> +                                    (list boolean?)))))
> +  ;; FIXME support an aliasing table as described here:
> +  ;; https://man.openbsd.org/table.5
> +  ;; One may have to use the record file for this.  I don't think
> tables support a table like this:
> +  ;; table "name" { joshua =
> joshua@gnucode.me,joshua@gnu-hurd.com,joshua@propernaming.org, root =
> root@gnucode.me }
> +  ;; If values is an absolute filename, then it will use said
> filename to house the table info.
> +  ;; filename must be an absolute filename.
> +  (data opensmtpd-table-data
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-table" "values"
> +                                   (list list-of-strings? assoc-
> list? file-exists?)))))
> +  ;; is a list of values or key values
> +  ;; eg: (list "mysite.me" "your-site.com")
> +  ;; eg: (list ("joshua" . "joshua@gnu.org") ("james" .
> "james@gnu.org"))
> +  ;; I am currently making these values be as assocation list of
> strings only.
> +  ;; FIXME should I allow a var like this?
> +  ;; (list (cons "gnucode.me" 234.949.392.23))
> +  ;; can be of type: (quote list-of-strings) or (quote assoc-list)
> +  ;; (opensmtpd-table-type record) returns the values' type.  The
> user SHOULD NEVER set the type.
> +  ;; TODO jpoiret: on irc reccomends that I just use an outside
> function to determine fieldname 'values', type.
> +  ;; it would be "simpler" and possibly easier for the next person
> working on this code to understand what is happening.
> +  (type opensmtpd-table-type
> +        (default #f)
> +        (thunked)
> +        (sanitize (lambda (var)
> +                    (cond ((opensmtpd-table-data this-record)
> +                           (if (list-of-strings? (opensmtpd-table-
> data this-record))
> +                               (quote list-of-strings)
> +                               (quote assoc-list)))
> +                          ((file-exists? (opensmtpd-table-data this-
> record))
> +                           (if (opensmtpd-table-file-db this-record)
> +                               (quote db)
> +                               (quote file)))
> +                          (else
> +                           (display "opensmtpd-table-type is
> broke\n")
> +                           (throw 'bad! var)))))))
> +
> +(define-record-type* <opensmtpd-ca>
> +  opensmtpd-ca make-opensmtpd-ca
> +  opensmtpd-ca?
> +  (name opensmtpd-ca-name
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-ca" "name" (list
> string?)))))
> +  (file opensmtpd-ca-file
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-ca" "file" (list
> file-exists?))))))
> +
> +(define-record-type* <opensmtpd-pki>
> +  opensmtpd-pki make-opensmtpd-pki
> +  opensmtpd-pki?
> +  (domain opensmtpd-pki-domain
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-pki" "domain"
> (list string?)))))
> +  ;; TODO/FIXME this should probably be a list of files.  The
> opensmtpd documentation says
> +  ;; that you could have a list of files:
> +  ;;
> +  ;; pki pkiname cert certfile
> +  ;; Associate certificate file certfile with host pkiname, and use
> that file to prove
> +  ;; the identity of the mail server to clients.  pkiname is the
> server's name, de‐
> +  ;; rived from the default hostname or set using either
> +  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-
> 6.8.0p2/etc/mailname or us‐
> +  ;; ing the hostname directive.  If a fallback certificate or SNI
> is wanted, the ‘*’
> +  ;; wildcard may be used as pkiname.
> +
> +  ;; A certificate chain may be created by appending one or many
> certificates, includ‐
> +  ;; ing a Certificate Authority certificate, to certfile.  The
> creation of certifi‐
> +  ;; cates is documented in starttls(8).
> +  (cert opensmtpd-pki-cert
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-pki" "cert" (list
> file-exists?)))))
> +  (key opensmtpd-pki-key
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-pki" "key" (list
> file-exists?)))))
> +  ; todo sanitize this. valid parameters are "none", "legacy", or
> "auto".
> +  (dhe opensmtpd-pki-dhe
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-dhe" "dhe" (list
> false? string?))))))
> +
> +(define-record-type* <opensmtpd-lmtp>
> +  opensmtpd-lmtp make-opensmtpd-lmtp
> +  opensmtpd-lmtp?
> +  (destination opensmtpd-lmtp-destination
> +               (default #f)
> +               (sanitize (lambda (var)
> +                           (my/sanitize var "opensmtpd-lmtp"
> "destination"
> +                                        (list string?)))))
> +  (rcpt-to opensmtpd-lmtp-rcpt-to
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-lmtp" "rcpt-to"
> +                                    (list false? string?))))))
> +
> +(define-record-type* <opensmtpd-mda>
> +  opensmtpd-mda make-opensmtpd-mda
> +  opensmtpd-mda?
> +  (name opensmtpd-mda-name
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-mda" "name"
> +                                 (list string?)))))
> +  ;; TODO should I allow this command to be a gexp?
> +  (command opensmtpd-mda-command
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-mda" "command"
> +                                    (list string?))))))
> +
> +(define-record-type* <opensmtpd-maildir>
> +  opensmtpd-maildir make-opensmtpd-maildir
> +  opensmtpd-maildir?
> +  (pathname opensmtpd-maildir-pathname
> +            (default #f)
> +            (sanitize (lambda (var)
> +                        (my/sanitize var "opensmtpd-maildir"
> "pathname"
> +                                     (list false? string?)))))
> +  (junk opensmtpd-maildir-junk
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-maildir" "junk"
> +                                 (list boolean?))))))
> +
> +(define-record-type* <opensmtpd-local-delivery>
> +  opensmtpd-local-delivery make-opensmtpd-local-delivery
> +  opensmtpd-local-delivery?
> +  (name opensmtpd-local-delivery-name
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-local-delivery"
> "name"
> +                                 (list string?)))))
> +  (method opensmtpd-local-delivery-method
> +          (default "mbox")
> +          (sanitize (lambda (var)
> +                      (cond
> +                       ((or (opensmtpd-lmtp? var)
> +                            (opensmtpd-maildir? var)
> +                            (opensmtpd-mda? var)
> +                            (string=? var "mbox")
> +                            (string=? var "expand-only")
> +                            (string=? var "forward-only"))
> +                        var)
> +                       (else
> +                        (begin
> +                          (display (string-append "<opensmtpd-local-
> delivery> fieldname 'method' must be of type \n"
> +                                                  "\"mbox\",
> \"expand-only\", \"forward-only\" \n"
> +                                                  "<opensmtpd-lmtp>,
> <opensmtpd-maildir>, \n"
> +                                                  "or <opensmtpd-
> mda>.\n"))
> +                          (throw 'bad! var)))))))
> +  (alias opensmtpd-local-delivery-alias
> +         (default #f)
> +         (sanitize (lambda (var)
> +                     (my/sanitize var "opensmtpd-local-delivery"
> "alias"
> +                                  (list false? opensmtpd-table?)))))
> +  (ttl opensmtpd-local-delivery-ttl
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-local-delivery" "ttl"
> +                                (list false? string?)))))
> +  (user opensmtpd-local-delivery-user
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-local-delivery"
> "user"
> +                                 (list false? string?)))))
> +  (userbase opensmtpd-local-delivery-userbase
> +            (default #f)
> +            (sanitize (lambda (var)
> +                        (my/sanitize var "opensmtpd-local-delivery"
> "userbase"
> +                                     (list false? opensmtpd-
> table?)))))
> +  (virtual opensmtpd-local-delivery-virtual
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-local-delivery"
> "virtual"
> +                                    (list false? opensmtpd-
> table?)))))
> +  (wrapper opensmtpd-local-delivery-wrapper
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-local-delivery"
> "wrapper"
> +                                    (list false? string?))))))
> +
> +;; FIXME/TODO this is a valid opensmtpd-relay record
> +;; (opensmtpd-relay
> +;;  (pki (opensmtpd-pki
> +;;        (domain "gnucode.me")
> +;;        (cert "opensmtpd.scm")
> +;;        (key "opensmtpd.scm"))))
> +;; BUT how does it relay the email?  What host does it use?
> +;; I think opensmtpd-relay-configuration needs "method" field.
> +;; the method field might need to be another record...BUT basically
> the relay has to have a 'backup', 'backup-mx',
> +;; or 'domain', or 'host' defined.
> +(define-record-type* <opensmtpd-relay>
> +  opensmtpd-relay make-opensmtpd-relay
> +  opensmtpd-relay?
> +  (name opensmtpd-relay-name
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-relay" "name"
> +                                 (list string?))))
> +        (default #f))
> +  (backup opensmtpd-relay-backup ;; boolean
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-relay" "backup"
> +                                   (list boolean?)))))
> +  (backup-mx opensmtpd-relay-backup-mx ;; string mx name
> +             (default #f)
> +             (sanitize (lambda (var)
> +                         (my/sanitize var "opensmtpd-relay" "backup-
> mx"
> +                                      (list false? string?)))))
> +  (helo opensmtpd-relay-helo
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-relay" "helo"
> +                                 (list false? string? opensmtpd-
> table?))))
> +        (default #f))
> +  (helo-src opensmtpd-relay-helo-src
> +        (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-relay" "helo-src"
> +                                   (list false? string? opensmtpd-
> table?))))
> +        (default #f))
> +  (domain opensmtpd-relay-domain
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-relay" "domain"
> +                                   (list false? opensmtpd-table?))))
> +          (default #f))
> +  (host opensmtpd-relay-host
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-relay" "host"
> +                                 (list false? string?))))
> +        (default #f))
> +  (pki opensmtpd-relay-pki
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-relay" "pki"
> +                                (list false? opensmtpd-pki?)))))
> +  (srs opensmtpd-relay-srs
> +       (default #f)
> +       (lambda (var)
> +         (my/sanitize var "opensmtpd-relay" "srs"
> +                      (list boolean?))))
> +  (tls opensmtpd-relay-tls
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-relay" "tls"
> +                                (list false? string?)))))
> +  (auth opensmtpd-relay-auth
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-relay" "auth"
> +                                 (list false? opensmtpd-table?))))
> +        (default #f))
> +  (mail-from opensmtpd-relay-mail-from
> +             (default #f))
> +  ;; string "127.0.0.1" or "<interface>" or "<table of IP
> addresses>"
> +  ;; TODO should I do some sanitizing to make sure that the string?
> here is actually an IP address or a valid interface?
> +  (src opensmtpd-relay-src
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-relay" "src"
> +                                (list false? string? opensmtpd-
> table?))))
> +       (default #f)))
> +
> +;; this record is used by <opensmtpd-filter-phase> &
> +;; <opensmtpd-match>
> +(define-record-type* <opensmtpd-option>
> +  opensmtpd-option make-opensmtpd-option
> +  opensmtpd-option?
> +  (option opensmtpd-option-option
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (if (and (string? var)
> +                               (or (string-in-list? var (list
> "fcrdns" "rdns"
> +                                                          "src"
> "helo"
> +                                                          "auth"
> "mail-from"
> +                                                          "rcpt-to"
> +                                                          "for"
> +                                                          "for any"
> "for local"
> +                                                          "for
> domain" "for rcpt-to"
> +                                                          "from any"
> "from auth"
> +                                                          "from
> local" "from mail-from"
> +                                                          "from
> rdns" "from socket"
> +                                                          "from src"
> "auth"
> +                                                          "helo"
> "mail-from"
> +                                                          "rcpt-to"
> "tag" "tls"))))
> +                                                          
> +                          var
> +                          (begin
> +                            (display (string-append "<opensmtpd-
> option> fieldname: 'option' is of type \n"
> +                                                    "string.  The
> string can be either 'fcrdns', \n"
> +                                                    " 'rdns', 'src',
> 'helo', 'auth', 'mail-from', or 'rcpt-to', \n"
> +                                                    "'for', 'for
> any', 'for local', 'for domain', 'for rcpt-to', \n"
> +                                                    "'from any',
> 'from auth', 'from local', 'from mail-from', 'from rdns', 'from
> socket', \n"
> +                                                    "'from src',
> 'auth helo', 'mail-from', 'rcpt-to', 'tag', or 'tls' \n"))
> +                                                    
> +                            (throw 'bad! var))))))
> +  (not opensmtpd-option-not
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-option" "not"
> +                                (list boolean?)))))
> +  (regex opensmtpd-option-regex
> +         (default #f)
> +         (sanitize (lambda (var)
> +                     (my/sanitize var "opensmtpd-option" "regex"
> +                                  (list boolean?)))))
> +  (data opensmtpd-option-data
> +         (default #f)
> +         (sanitize (lambda (var)
> +                     (my/sanitize var "opensmtpd-option" "data"
> +                                  (list false? string? opensmtpd-
> table?))))))
> +
> +(define-record-type* <opensmtpd-filter-phase>
> +  opensmtpd-filter-phase make-opensmtpd-filter-phase
> +  opensmtpd-filter-phase?
> +  (name opensmtpd-filter-phase-name ;; string chain-name
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-filter-phase" "name"
> +                                 (list string?)))))
> +  (phase opensmtpd-filter-phase-phase ;; string
> +              (default #f)
> +              (sanitize (lambda (var)
> +                          (if (and (string? var)
> +                                   (string-in-list? var (list
> "connect"
> +                                                              "helo"
> +                                                              "mail-
> from"
> +                                                              "rcpt-
> to"
> +                                                              "data"
> +                                                             
> "commit")))
> +                              var
> +                              (begin
> +                                (display (string-append "<opensmtpd-
> filter-phase> fieldname: 'phase' is of type \n"
> +                                                        "string. 
> The string can be either 'connect',"
> +                                                        " 'helo',
> 'mail-from', 'rcpt-to', 'data', or 'commit.'\n "))
> +
> +                                (throw 'bad! var))))))
> +  (options opensmtpd-filter-phase-options
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       ;; returns #t if list is a unique list of
> <opensmtpd-option>
> +                       (define (list-of-opensmtpd-option? list)
> +                         (and (list-of-type? list opensmtpd-option?)
> +                              (not (contains-duplicate? list))))
> +
> +                       (define (list-has-duplicates-or-non-
> opensmtpd-option list)
> +                         (not (list-of-opensmtpd-option? list)))
> +
> +                       ;; input <opensmtpd-option>
> +                       ;; return #t if <opensmtpd-option> fieldname
> 'option'
> +                       ;; that needs a corresponding table has one. 
> Otherwise #f
> +                       (define (opensmtpd-option-has-table? record)
> +                         (define decision (opensmtpd-option-option
> record))
> +                         (and (string? decision)
> +                              ;; if option needs a table, check for
> a table
> +                              (if (string-in-list? decision (list
> "src"
> +                                                                 
> "helo"
> +                                                                 
> "mail-from"
> +                                                                 
> "rcpt-to"))
> +                                  (opensmtpd-table? (opensmtpd-
> option-data record))
> +                                  #t)))
> +
> +                       (define (list-of-opensmtpd-option-has-table?
> list)
> +                         (list-of-type? list opensmtpd-option-has-
> table?))
> +
> +                       (define (some-opensmtpd-option-in-list-lack-
> table? list)
> +                         (not (list-of-opensmtpd-option-has-table?
> list)))
> +
> +                       (sanitize-options-for-filter-phase-
> configuration var)
> +                       )))
> +  (decision opensmtpd-filter-phase-decision
> +            (default #f)
> +            (sanitize (lambda (var)
> +                        (if (and (string? var)
> +                                 (string-in-list? var (list "bypass"
> "disconnect"
> +                                                            "reject"
> "rewrite" "junk")))
> +                            var
> +                            (begin
> +                              (display (string-append "<opensmtpd-
> filter-decision> fieldname: 'decision' is of type \n"
> +                                                      "string.  The
> string can be either 'bypass',"
> +                                                      "
> 'disconnect', 'reject', 'rewrite', or 'junk'.\n"))
> +                              (throw 'bad! var))))))
> +  (message opensmtpd-filter-phase-message
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-filter-phase"
> "message"
> +                                    (list false? string?)))))
> +  (value opensmtpd-filter-phase-value
> +         (default #f)
> +         (sanitize (lambda (var)
> +                     (my/sanitize var "opensmtpd-filter-phase"
> "value"
> +                                  (list false? number?))))))
> +
> +(define-record-type* <opensmtpd-filter>
> +  opensmtpd-filter make-opensmtpd-filter
> +  opensmtpd-filter?
> +  (name opensmtpd-filter-name
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-filter" "name"
> +                                 (list string?)))))
> +  (exec opensmtpd-filter-exec
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-filter" "exec"
> +                                 (list boolean?)))))
> +  (proc opensmtpd-filter-proc ; a string like "rspamd" or the
> command to start it like "/path/to/rspamd --option=arg --2nd-
> option=arg2"
> +             (default #f)
> +             (sanitize (lambda (var)
> +                         (my/sanitize var "opensmtpd-filter" "proc"
> +                                      (list string? list-of-strings-
> or-gexps?))))))
> +
> +;; There is another type of filter that opensmtpd supports, which is
> a filter chain.
> +;; A filter chain is a list of <opensmtpd-filter-phase> and
> <opensmtpd-filter>.
> +;; This lets you apply several filters under one filter name.  I
> could have defined
> +;; a record type for it, but the record would only have had two
> fields: name and list-of-filters.
> +;; Why write that as a record?  That's too simple.
> +;; returns #t if list is a unique list of <opensmtpd-filter> or
> <opensmtpd-filter-phase>
> +;; returns # otherwise
> +(define (opensmtpd-filter-chain? %filters)
> +  (and (list-of-unique-filter-or-filter-phase? %filters)
> +       (< 1 (length %filters))))
> +
> +(define-record-type* <opensmtpd-interface>
> +  opensmtpd-interface make-opensmtpd-interface
> +  opensmtpd-interface?
> +  ;; interface may be an IP address, interface group, or domain name
> +  (interface opensmtpd-interface-interface
> +             (default "lo"))
> +  (family opensmtpd-interface-family
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (cond
> +                       ((eq? #f var) ;; var == #f
> +                        var)
> +                       ((and (string? var)
> +                             (string-in-list? var (list "inet4"
> "inet6")))
> +                        var)
> +                       (else
> +                        (begin
> +                          (display "<opensmtpd-interface> fieldname
> 'family' must be string \"inet4\" or \"inet6\".\n")
> +                          (throw 'bad! var)))))))
> +  (auth opensmtpd-interface-auth
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-interface" "auth"
> +                                 (list boolean? table-whose-data-
> are-assoc-list?)))))
> +  (auth-optional opensmtpd-interface-auth-optional
> +                 (default #f)
> +                 (sanitize (lambda (var)
> +                             (my/sanitize var "opensmtpd-interface"
> "auth-optional"
> +                                          (list boolean?
> +                                                table-whose-data-
> are-assoc-list?)))))
> +  ;; TODO add a ca entry?
> +  ;; string FIXME/TODO sanitize this to support a gexp.  That way
> way the
> +  ;; includes directive can include my hacky scheme code that I use
> for opensmtpd-dkimsign.
> +  (filters opensmtpd-interface-filters
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (sanitize-filter-phases var))))
> +  (hostname opensmtpd-interface-hostname
> +            (default #f)
> +            (sanitize (lambda (var)
> +                        (my/sanitize var "opensmtpd-interface"
> "hostname"
> +                                     (list false? string?)))))
> +  (hostnames opensmtpd-interface-hostnames
> +             (default #f)
> +             (sanitize (lambda (var)
> +                         (my/sanitize var "opensmtpd-interface"
> "hostnames"
> +                                      (list false? table-whose-data-
> are-assoc-list?)))))
> +  (mask-src opensmtpd-interface-mask-src
> +            (default #f)
> +            (sanitize (lambda (var)
> +                        (my/sanitize var "opensmtpd-interface"
> "mask-src"
> +                                     (list boolean?)))))
> +  (disable-dsn opensmtpd-interface-disable-dsn
> +          (default #f))
> +  (pki opensmtpd-interface-pki
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-interface" "pki"
> +                                (list false? opensmtpd-pki?)))))
> +  (port opensmtpd-interface-port
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-interface" "port"
> +                                 (list false? integer?)))))
> +  (proxy-v2 opensmtpd-interface-proxy-k2
> +            (default #f))
> +  (received-auth opensmtpd-interface-received-auth
> +                 (default #f))
> +  ;; TODO add in a senders option!
> +  ;; string or <opensmtpd-senders> record
> +  ;; (senders opensmtpd-interface-senders
> +  ;;          (sanitize (lambda (var)
> +  ;;                      (my/sanitize var "opensmtpd-interface"
> "port" (list false? integer?))))
> +  ;;          (default #f))
> +  (secure-connection opensmtpd-interface-secure-connection
> +                     (default #f)
> +                     (sanitize (lambda (var)
> +                                 (cond ((boolean? var)
> +                                        var)
> +                                       ((and (string? var)
> +                                             (string-in-list? var
> +                                                              (list
> "smtps" "tls"
> +                                                                   
> "tls-require"
> +                                                                   
> "tls-require-verify")))
> +                                        var)
> +                                       (else
> +                                        (begin
> +                                          (display (string-append
> "<opensmtd-listen-on> fieldname 'secure-connection' can be \n"
> +                                                                 
> "one of the following strings: \n'smtps', 'tls', 'tls-require', \n"
> +                                                                 
> "or 'tls-require-verify'.\n"))
> +                                          (throw 'bad! var)))))))
You might want to reduce horizontal space here, even if guix style
tells you otherwise.
> +  (tag opensmtpd-interface-tag
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-interface" "tag"
> +                                (list false? string?))))
> +       (default #f)))
> +
> +(define-record-type* <opensmtpd-socket-configuration>
> +  opensmtpd-socket-configuration make-opensmtpd-socket-configuration
> +  opensmtpd-socket-configuration?
> +  ;; false or <opensmtpd-filter> or list of <opensmtpd-filter>
> +  (filters opensmtpd-socket-configuration-filters
> +           (sanitize (lambda (var)
> +                       (sanitize-filter-phases var)))
> +          (default #f))
> +  (mask-src opensmtpd-socket-configuration-mask-src
> +            (default #f))
> +  (tag opensmtpd-socket-configuration-tag
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-interface" "tag"
> +                                (list false? string?))))
> +       (default #f)))
> +
> +
> +(define-record-type* <opensmtpd-match>
> +  opensmtpd-match make-opensmtpd-match
> +  opensmtpd-match?
> +  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
> +  ;;is #t, then the match record will be a reject match record.
> +  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action
> 'reject))
> +  ;; To do this, I will also have to  'reject' mutually exclusive.
> AND an match with 'reject' can have no action defined.
> +  (action opensmtpd-match-action
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (if (or (opensmtpd-relay? var)
> +                              (opensmtpd-local-delivery? var)
> +                              (eq? (quote reject) var))
> +                          var
> +                          (begin
> +                            (display
> +                             (string-append "<opensmtpd-match>
> fieldname 'action' is of type <opensmtpd-relay>, \n"
> +                                            "<opensmtpd-local-
> delivery>, or (quote reject).\n"
> +                                            "If its var is (quote
> reject), then the match rejects the incoming message\n"
> +                                            "during the SMTP
> dialogue.\n"))
> +                            (throw 'bad! var))))))
> +  (options opensmtpd-match-options
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (cond ((not var)
> +                              #f)
> +                             ((not (list-of-unique-opensmtpd-option?
> var))
> +                              (throw-error var '("<opensmtpd-match>
> fieldname 'options' is a list of unique \n"
> +                                                 "<opensmtpd-option>
> records. \n")))
> +                           (else (sanitize-list-of-options-for-
> match-configuration var)))))))
> +
> +(define-record-type* <opensmtpd-smtp>
> +  opensmtpd-smtp make-opensmtpd-smtp
> +  opensmtpd-smtp?
> +  (ciphers opensmtpd-smtp-ciphers
> +           (default #f)
> +           (sanitize (lambda (var)
> +                       (my/sanitize var "opensmtpd-smtp" "ciphers"
> +                                    (list false? string?)))))
> +  (limit-max-mails opensmtpd-smtp-limit-max-mails
> +                   (default #f)
> +                   (sanitize (lambda (var)
> +                               (my/sanitize var "opensmtpd-smtp"
> "limit-max-mails"
> +                                            (list false?
> integer?)))))
> +  (limit-max-rcpt opensmtpd-smtp-limit-max-rcpt
> +                  (default #f)
> +                  (sanitize (lambda (var)
> +                              (my/sanitize var "opensmtpd-smtp"
> "limit-max-rcpt"
> +                                           (list false?
> integer?)))))
> +  (max-message-size opensmtpd-smtp-max-message-size
> +                    (default #f)
> +                    (sanitize (lambda (var)
> +                                (my/sanitize var "opensmtpd-smtp"
> "max-message-size"
> +                                             (list false? integer?
> string?)))))
> +  ;; FIXME/TODO the sanitize function of sub-addr-delim should
> accept a string of length one not string?
> +  (sub-addr-delim opensmtpd-smtp-sub-addr-delim
> +                  (default #f)
> +                  (sanitize (lambda (var)
> +                              (my/sanitize var "opensmtpd-smtp"
> "sub-addr-delim"
> +                                           (list false? integer?
> string?))))))
> +
> +(define-record-type* <opensmtpd-srs>
> +  opensmtpd-srs make-opensmtpd-srs
> +  opensmtpd-srs?
> +  ;; TODO should this be a file?
> +  (key opensmtpd-srs-key
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-srs" "key"
> +                                (list false? boolean? string?)))))
> +  ;; TODO should this also be a file?
> +  (backup-key opensmtpd-srs-backup-key
> +              (default #f)
> +              (sanitize (lambda (var)
> +                          (my/sanitize var "opensmtpd-srs" "backup-
> key"
> +                                       (list false? integer?)))))
> +  (ttl-delay opensmtpd-srs-ttl-delay
> +             (default #f)
> +             (sanitize (lambda (var)
> +                         (my/sanitize var "opensmtpd-srs" "ttl-
> delay"
> +                                      (list false? string?))))))
> +
> +(define-record-type* <opensmtpd-queue>
> +  opensmtpd-queue make-opensmtpd-queue
> +  opensmtpd-queue?
> +  (compression opensmtpd-queue-compression
> +               (default #f)
> +               (sanitize (lambda (var)
> +                           (my/sanitize var "opensmtpd-queue"
> "compression"
> +                                        (list boolean?)))))
> +  (encryption opensmtpd-queue-encryption
> +              (default #f)
> +              (sanitize (lambda (var)
> +                          (my/sanitize var "opensmtpd-queue"
> "encryption"
> +                                       (list boolean? string? file-
> exists?)))))
> +  (ttl-delay opensmtpd-queue-ttl-delay
> +             (default #f)
> +             (sanitize (lambda (var)
> +                         (my/sanitize var "opensmtpd-queue" "ttl-
> delay"
> +                                      (list false? string?))))))
> +
>  (define-record-type* <opensmtpd-configuration>
>    opensmtpd-configuration make-opensmtpd-configuration
>    opensmtpd-configuration?
> -  (package     opensmtpd-configuration-package
> -               (default opensmtpd))
> +  (package opensmtpd-configuration-package
> +           (default opensmtpd))
>    (config-file opensmtpd-configuration-config-file
> -               (default %default-opensmtpd-config-file))
> +               (default #f))
> +  ;; FIXME/TODO should I include a admd authservid entry?
> +
> +  ;; TODO sanitize this properly with perhaps a <sanitize-
> configuration>.
> +  (bounce opensmtpd-configuration-bounce
> +          (default #f)
> +          (sanitize (lambda (var)
> +                      (my/sanitize var "opensmtpd-configuration"
> "bounce"
> +                                   (list false? list?)))))
> +  (cas opensmtpd-configuration-cas
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-configuration" "cas"
> +                                (list false? list-of-opensmtpd-
> ca?)))))
> +  ;; list of many records of type opensmtpd-interface
> +  (listen-ons opensmtpd-configuration-listen-ons
> +              (default (list (opensmtpd-interface)))
> +              (sanitize (lambda (var)
> +                          (if (list-of-opensmtpd-interface? var)
> +                              var
> +                              (begin
> +                                (display "<opensmtpd-configuration>
> fieldname 'listen-ons' expects a list of records ")
> +                                (display "of one or more unique
> <opensmtpd-interface> records.\n")
> +                                (throw 'bad! var))))))
> +  ;; accepts type <opensmtpd-socket-configuration>
> +  (listen-on-socket opensmtpd-configuration-listen-on-socket
> +                    (default (opensmtpd-socket-configuration)))
> +  (includes opensmtpd-configuration-includes ;; list of strings of
> absolute path names
> +            (default #f)
> +            (sanitize (lambda (var)
> +                        (my/sanitize var "opensmtpd-configuration"
> "includes"
> +                                     (list false? list-of-strings?
> gexp?)))))
> +  (matches opensmtpd-configuration-matches
> +           (default (list (opensmtpd-match
> +                           (action (opensmtpd-local-delivery
> +                                    (name "local")
> +                                    (method "mbox")))
> +                           (options (list
> +                                     (opensmtpd-option
> +                                      (option "for local")))))
> +                          (opensmtpd-match
> +                           (action (opensmtpd-relay
> +                                    (name "outbound")))
> +                           (options (list
> +                                     (opensmtpd-option
> +                                      (option "from local"))
> +                                     (opensmtpd-option
> +                                      (option "for any")))))))
> +           ;; TODO perhaps I should sanitize this function like I
> sanitized the 'filters'.
> +           ;; I definitely should sanitize this function a bit
> more.  For example, you could have two different
> +           ;; actions, one for local delivery and one for remote,
> with the same name.  I should make sure that
> +           ;; I have no two different actions with the same name.
> +           (sanitize (lambda (var)
> +                       ;; Should we do more sanitizing here?  eg:
> "from socket" should NOT have a table or value
> +                       var
> +                       (my/sanitize var "opensmtpd-configuration"
> "matches"
> +                                    (list list-of-unique-opensmtpd-
> match?)))))
> +  ;; list of many records of type mda-wrapper
> +  ;; TODO/FIXME support using gexps here
> +  ;; eg (list "name" gexp)
> +  (mda-wrappers opensmtpd-configuration-mda-wrappers
> +                (default #f)
> +                (sanitize (lambda (var)
> +                            (my/sanitize var
> +                                         "opensmtpd-configuration"
> +                                         "mda-wrappers"
> +                                         (list false? string?)))))
> +  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
> +                    (default 100)
> +                    (sanitize (lambda (var)
> +                                (my/sanitize var "opensmtpd-
> configuration" "mta-max-deferred"
> +                                             (list number?)))))
> +
> +  ;; TODO should I add a fieldname proc _proc-name_ _command_ as
> found in the man 5 smtpd.conf ?
> +
> +  (queue opensmtpd-configuration-queue
> +         (default #f)
> +         (sanitize (lambda (var)
> +                     (my/sanitize var "opensmtpd-configuration"
> "queue"
> +                                  (list false? opensmtpd-queue?)))))
> +  (smtp opensmtpd-configuration-smtp
> +        (default #f)
> +        (sanitize (lambda (var)
> +                    (my/sanitize var "opensmtpd-configuration"
> "smtp"
> +                                 (list false? opensmtpd-smtp?)))))
> +  (srs opensmtpd-configuration-srs
> +       (default #f)
> +       (sanitize (lambda (var)
> +                   (my/sanitize var "opensmtpd-configuration" "srs"
> +                                (list false? opensmtpd-srs?)))))
>    (setgid-commands? opensmtpd-setgid-commands? (default #t)))
>  
> +;; this help procedure is used 3 or 4 times by sanitize-list-of-
> options-for-match-configuration
> +(define* (throw-error-duplicate-option option error-arg #:key
> (record-name "match"))
> +  (throw-error error-arg
> +               (list (string-append "<opensmtpd-" record-name ">'s
> fieldname 'options' has two\n")
> +                     (string-append "<opensmtpd-option> records with
> fieldname 'option' with value '" option "'. \n")
> +                     (string-append "You can only have one option
> with value '" option "' in the options list.\n"))))
> +
> +;; this procedure sanitizes the fieldname opensmtpd-match-options
> +(define* (sanitize-list-of-options-for-match-configuration %options)
> +  (let loop ((%traversing-options %options)
> +             ;; sanitized-options is an alist that may end of
> looking like:
> +             ;; (("for" (opensmtpd-option (option "for any")))
> +             ;;  ("from" (opensmtpd-option (option "from any"))))
> +             (%sanitized-options '()))
> +    (if (null? %traversing-options)
> +        (remove false?
> +                (list
> +                 (assoc-ref %sanitized-options "for")
> +                 (assoc-ref %sanitized-options "from")
> +                 (assoc-ref %sanitized-options "auth")
> +                 (assoc-ref %sanitized-options "helo")
> +                 (assoc-ref %sanitized-options "mail-from")
> +                 (assoc-ref %sanitized-options "rcpt-to")
> +                 (assoc-ref %sanitized-options "tag")
> +                 (assoc-ref %sanitized-options "tls")))
> +        (let* ((option-record (car %traversing-options))
> +               (option-string (opensmtpd-option-option option-
> record)))
> +          (cond ((string=? "auth" option-string)
> +                 (if (assoc-ref %sanitized-options "auth")
> +                     (throw-error-duplicate-option "auth"
> %traversing-options)
> +                     (loop (cdr %traversing-options) (alist-cons
> "auth" option-record %sanitized-options))))
> +                ((string=? "helo" option-string)
> +                 (cond [(assoc-ref %sanitized-options "helo")
> +                        (throw-error-duplicate-option "helo"
> %traversing-options)]
> +                       [(not (opensmtpd-option-data option-record))
> +                        (throw-error option-record
> +                                     (list "<opensmtpd-option> with
> fieldname 'option' with value 'helo' \n"
> +                                           "must have a 'data' of
> type string or <opensmtpd-table>.\n"))]
> +                       [else (loop (cdr %traversing-options) (alist-
> cons "helo" option-record %sanitized-options))]))
> +                ((string=? "mail-from" option-string)
> +                 (cond ((assoc-ref %sanitized-options "mail-from")
> +                        (throw-error-duplicate-option "mail-from"
> %traversing-options))
> +                       ((not (opensmtpd-option-data option-record))
> +                        (throw-error option-record
> +                                     (list "<opensmtpd-option> with
> fieldname 'option' with value 'mail-from' \n"
> +                                           "must have a 'data' of
> type string or <opensmtpd-table>.\n")))
> +                       (else (loop (cdr %traversing-options) (alist-
> cons "mail-from" option-record %sanitized-options)))))
> +                ((string=? "rcpt-to" option-string)
> +                 (cond [(assoc-ref %sanitized-options "rcpt-to")
> +                        (throw-error-duplicate-option "rcpt-to"
> %traversing-options)]
> +                       [(not (opensmtpd-option-data option-record))
> +                        (throw-error option-record
> +                                     (list "<opensmtpd-option> with
> fieldname 'option' with value 'rcpt-to' \n"
> +                                           "must have a 'data' of
> type string or <opensmtpd-table>.\n"))]
> +                       [else (loop (cdr %traversing-options) (alist-
> cons "rcpt-to" option-record %sanitized-options))]))
> +                ((string=? "tag" option-string)
> +                 (cond ((assoc-ref %sanitized-options "tag")
> +                        (throw-error-duplicate-option "tag"
> %traversing-options))
> +                       ((not (string? (opensmtpd-option-data option-
> record)))
> +                        (throw-error option-record
> +                                     (list "<opensmtpd-option> with
> fieldname 'option' with value 'tag' \n"
> +                                           "must have a 'data' of
> type string.\n")))
> +                       (else (loop (cdr %traversing-options) (alist-
> cons "tag" option-record %sanitized-options)))))
> +                ((string=? "tls" option-string)
> +                 (cond [(assoc-ref %sanitized-options "tls")
> +                        (throw-error-duplicate-option "tls"
> %traversing-options)]
> +                       [(or (opensmtpd-option-data option-record)
> +                            (opensmtpd-option-regex option-record))
> +                        (throw-error option-record
> +                                     (list "<opensmtpd-option> with
> fieldname 'option' with value 'tls', then \n"
> +                                           "fieldname 'data' cannot
> be defined.\n"))]
> +                       [else (loop (cdr %traversing-options) (alist-
> cons "tls" option-record %sanitized-options))]))
> +                ((string=? "for" (substring option-string 0 3))
> +                 (cond ((assoc-ref %sanitized-options "for")
> +                        (throw-error %options
> +                                     `("<opensmtpd-match>'s
> fieldname 'options' can only have one 'for' option. \n"
> +                                       "But '" ,option-string "' and
> '"
> +                                       ,(opensmtpd-option-option
> (assoc-ref %sanitized-options "for")) "' are present.\n")))
> +                       ((and (string-in-list? option-string (list
> "for any" "for local")) ; for any cannot have a data field.
> +                             (or (opensmtpd-option-data option-
> record)
> +                                 (opensmtpd-option-regex option-
> record)))
> +                        (throw-error option-record
> +                                     (list "When <openmstpd-option-
> configuration>'s fieldname 'options' value is 'for any' \n"
> +                                           "or 'for local', then its
> 'data' and 'regex' field must be #f. \n")))
> +                       ((and (string-in-list? option-string (list
> "for domain" "for rcpt-to")) ; for domain must have a data field.
> +                             (not (opensmtpd-option-data option-
> record)))
> +                        (throw-error option-record
> +                                     (list "When <openmstpd-option-
> configuration>'s fieldname 'options' value is 'for domain' \n"
> +                                           "or 'for rcpt-to', then
> its 'data' field must be a string or an \n"
> +                                           "<opensmtpd-table>
> record.\n")))
> +                       (else (loop (cdr %traversing-options) (alist-
> cons "for" option-record %sanitized-options)))))
> +                ((string=? "from" (substring option-string 0 4))
> +                 (cond ((assoc-ref %sanitized-options "from")
> +                        (throw-error %options
> +                                     `("<opensmtpd-match>'s
> fieldname 'options' can only have one 'from' option. \n"
> +                                       "But '" ,option-string "' and
> '"
> +                                       ,(opensmtpd-option-option
> (assoc-ref %sanitized-options "from")) "' are present.\n")))
> +                       ((and (string-in-list? option-string (list
> "from any" "from local" "from socket")) ; for any cannot have a data
> field.
> +                             (or (opensmtpd-option-data option-
> record)
> +                                 (opensmtpd-option-regex option-
> record)))
> +                        (throw-error option-record
> +                                     (list "When <openmstpd-option-
> configuration>'s fieldname 'options' value is 'from any', \n"
> +                                           " 'from local', or 'from
> socket', then its 'data' and 'regex' field must be #f. \n")))
> +                       ((and (string-in-list? option-string (list
> "from mail-from" "from src")) ; for domain must have a data field.
> +                             (not (opensmtpd-option-data option-
> record)))
> +                        (throw-error option-record
> +                                     (list "When <openmstpd-option-
> configuration>'s fieldname 'options' value is 'from mail-from' \n"
> +                                           "or 'from src', then its
> 'data' field must be a string or an \n"
> +                                           "<opensmtpd-table>
> record.\n")))
> +                       (else (loop (cdr %traversing-options) (alist-
> cons "from" option-record %sanitized-options))))))))))
> +
> +;; if the list of filters in opensmtpd-interface-filters
> +;; and in opensmtpd-socket-configuration-filters has two
> +;; filters with the same name, this will return #t
> +;; otherwise false
> +(define (duplicate-filter-name? %filters)
> +  (contains-duplicate?
> +   (let loop ((%filters %filters))
> +     (if (null? %filters)
> +         '()
> +         (cond
> +          ((opensmtpd-filter-phase? (car %filters))
> +           (cons (opensmtpd-filter-phase-name (car %filters))
> +                 (loop (cdr %filters))))
> +          (else
> +           (cons (opensmtpd-filter-name (car %filters))
> +                 (loop (cdr %filters)))))))))
> +
> +(define (list-has-duplicates-or-non-filters? list)
> +  (not (list-of-unique-filter-or-filter-phase? list)))
> +
> +(define (filter-phase-has-message-and-value? record)
> +  (and (opensmtpd-filter-phase-message record)
> +       (opensmtpd-filter-phase-value record)))
> +
> +;; return #t if phase needs a message. Or if the message did not
> start with a 4xx or 5xx status code.
> +;; otherwise #f
> +(define (filter-phase-decision-lacks-proper-message? record)
> +  (define decision (opensmtpd-filter-phase-decision record))
> +  (if (string-in-list? decision (list "disconnect" "reject"))
> +      ;; this message needs to be RFC compliant, meaning
> +      ;; that it need to start with 4xx or 5xx status code
> +      (cond ((eq? #f (opensmtpd-filter-phase-message record))
> +             #t)
> +            ((string? (opensmtpd-filter-phase-message record))
> +             (let ((number (string->number
> +                            (substring
> +                             (opensmtpd-filter-phase-message record)
> 0 3))))
> +               (if (and (number? number)
> +                        (and (< number 600) (> number 399)))
> +                   #f
> +                   #t))))
> +      #f))
> +
> +;; 'decision' "rewrite" requires 'value' to be a number.
> +(define (filter-phase-lacks-proper-value? record)
> +  (define decision (opensmtpd-filter-phase-decision record))
> +  (if (string=? "rewrite" decision)
> +      (if (and (number? (opensmtpd-filter-phase-value record))
> +               (eq? #f (opensmtpd-filter-phase-message record)))
> +          #f
> +          #t)
> +      #f))
> +
> +;; 'decision' "junk" or "bypass" cannot have a message or a value.
> +(define (filter-phase-has-incorrect-junk-or-bypass? record)
> +  (and
> +   (string-in-list?
> +    (opensmtpd-filter-phase-decision record)
> +    (list "junk" "bypass"))
> +   (or
> +    (opensmtpd-filter-phase-value record)
> +    (opensmtpd-filter-phase-message record))))
> +
> +(define (filter-phase-junks-after-commit? record)
> +  (and (string=? (opensmtpd-filter-phase-decision record) "junk")
> +       (string=? (opensmtpd-filter-phase-phase record) "commit")))
> +
> +;; returns #t if list is a unique list of <opensmtpd-filter> or
> <opensmtpd-filter-phase>
> +;; returns # otherwise
> +(define (list-of-unique-filter-or-filter-phase? %filters)
> +  (and (list? %filters)
> +       (not (null? %filters))
> +       ;; this list is made up of only <opensmtpd-filter-phase> or
> <opensmtpd-filter>
> +       (primitive-eval
> +        (cons 'and (map (lambda (filter)
> +                          (or (opensmtpd-filter? filter)
> +                              (opensmtpd-filter-phase? filter)))
> +                        %filters)))
> +       (not (contains-duplicate? %filters))))
> +
> +;; the sanitize procedures used for sanitizing <opensmtpd-interface>
> and
> +;; <opensmtpd-socket-configuration> fieldname 'filters'.
> +;; It primarily sanitizes <filter-phases>.  The only sanitization it
> does
> +;; for <filter>s, is no make sure there are no duplicate filter
> names.
> +(define (sanitize-filter-phases %list)
> +  ;; the order of the first two tests in this cond is important.
> +  ;; (false?) has to be 1st and (list-has-duplicates-or-non-
> filters?) has to be second.
> +  ;; You may optionally re-order the other alternates in the cond.
> +  (cond ((false? %list)
> +         #f)
> +        ((list-has-duplicates-or-non-filters? %list)
> +         (begin
> +           (display (string-append "<opensmtpd-interface> fieldname:
> 'filters' is a list, in which each unique element \n"
> +                                   "is of type <opensmtpd-filter> or
> <opensmtpd-filter-phase>.\n"))
> +           (throw 'bad! %list)))
> +        ((duplicate-filter-name? %list)
> +         (throw-error %list (list "has a duplicate filter name.\n")
> +                      #:record-name "interface"
> +                      #:fieldname "filters"))
> +        (else
> +         (let loop ([%traversing-list %list]
> +                    [%original-list %list])
> +           (if (null? %traversing-list)
> +               %original-list
> +               (cond [(opensmtpd-filter? (car %traversing-list))
> +                      (loop (cdr %traversing-list) %original-list)]
> +                     [(filter-phase-has-message-and-value? (car
> %traversing-list))
> +                      (begin
> +                        (display (string-append "<opensmtpd-filter-
> phase> cannot have defined fieldnames 'value' \n"
> +                                                "and 'message'.\n"))
> +                        (throw 'bad! (car %traversing-list)))]
> +                     [(filter-phase-decision-lacks-proper-message?
> (car %traversing-list))
> +                      (begin
> +                        (display (string-append "<opensmtpd-filter-
> phase> fieldname: 'decision' options \n"
> +                                                "\"disconnect\" and
> \"reject\" require fieldname 'message' to have an RFC \n"
> +                                                "compliant string,
> which means that the string must begin with a 4xx or 5xx status
> code.\n"))
> +                        (throw 'bad! (car %traversing-list)))]
> +                     [(filter-phase-lacks-proper-value? (car
> %traversing-list))
> +                      (begin
> +                        (display (string-append "<opensmtpd-filter-
> phase> fieldname: 'decision' option \n"
> +                                                "\"rewrite\"
> requires fieldname 'value' to have a number.\n"))
> +                        (throw 'bad! (car %traversing-list)))]
> +                     [(filter-phase-has-incorrect-junk-or-bypass?
> (car %traversing-list))
> +                      (begin
> +                        (display (string-append "<opensmtpd-filter-
> phase> fieldname 'decision' option \n"
> +                                                "\"junk\" or
> 'bypass' cannot have a defined fieldnames 'message' or 'value'.\n"))
> +                        (throw 'bad! (car %traversing-list)))]
> +                     [(filter-phase-junks-after-commit? (car
> %traversing-list))
> +                      (begin
> +                        (display (string-append "<opensmtpd-filter-
> phase> fieldname 'decision' option \n"
> +                                                "\"junk\" cannot
> junk an email during 'phase' \"commit\".\n"))
> +                        (throw 'bad! (car %traversing-list)))]
> +                     [else (loop (cdr %traversing-list) %original-
> list)]))))))
> +
> +(define* (sanitize-options-for-filter-phase-configuration %options)
> +  (if (false? %options)
> +      (throw-error #f
> +                   (list "must have at least one opensmtpd-option
> record.")
> +                   #:record-name "filter-phase"
> +                   #:fieldname "options")
> +      (let loop ((%traversing-options %options)
> +                 ;; sanitized-options is an alist that may end of
> looking like:
> +                 ;; (("for" (opensmtpd-option (option "for any")))
> +                 ;;  ("from" (opensmtpd-option (option "from
> any"))))
> +                 (%sanitized-options '()))
> +        (if (null? %traversing-options)
> +            (remove false?
> +                    (list
> +                     (assoc-ref %sanitized-options "fcrdns")
> +                     (assoc-ref %sanitized-options "rdns")
> +                     (assoc-ref %sanitized-options "src")
> +                     (assoc-ref %sanitized-options "helo")
> +                     (assoc-ref %sanitized-options "auth")
> +                     (assoc-ref %sanitized-options "mail-from")
> +                     (assoc-ref %sanitized-options "rcpt-to")))
> +            (let* ((option-record (car %traversing-options))
> +                   (option-string (opensmtpd-option-option option-
> record)))
> +              (cond ((assoc-ref %sanitized-options option-string)
> +                     ;; if we see two "rdns" (for example), throw a
> "duplicate
> +                     ;; option" error.
> +                     (throw-error-duplicate-option option-string
> option-record
> +                                                   #:record-name
> "filter-phase"))
> +                    ;; the next 4 options must have fieldname 'data'
> defined.
> +                    ((or (string=? option-string "src")
> +                         (string=? option-string "helo")
> +                         (string=? option-string "mail-from")
> +                         (string=? option-string "rcpt-to"))
> +                     (if (not (opensmtpd-table?
> +                               (opensmtpd-option-data option-
> record)))
> +                         (throw-error option-record (list "must have
> fieldname 'data' defined.\n")
> +                                      #:record-name "option"
> +                                      #:fieldname option-string)
> +                         (loop (cdr %traversing-options)
> +                               (alist-cons option-string option-
> record %sanitized-options))))
> +                    ;;fcrdns cannot have fieldname data defined
> +                    ((string=? "fcrdns" option-string)
> +                     (if (opensmtpd-option-data option-record)
> +                         (throw-error option-record (list "cannot
> have fieldname data defined.\n")
> +                                      #:record-name "option"
> +                                      #:fieldname "rdns")
> +                         (loop (cdr %traversing-options)
> +                               (alist-cons "fcrdns" option-record
> %sanitized-options))))
> +                    ;; rdns and auth cannot be made invalidly; skip
> testing them.
> +                    ((or (string=? "rdns" option-string)
> +                         (string=? "auth" option-string))
> +                     (loop (cdr %traversing-options)
> +                           (alist-cons "auth" option-record
> +                                       %sanitized-options)))
> +                    (else (throw-error option-record
> +                                       (list "has an invalid option
> name.")
> +                                       #:record-name "filter-phase"
> +                                       #:fieldname option-
> string))))))))
> +
> +(define* (throw-error var %strings
> +                      #:key
> +                      (record-name #f)
> +                      (fieldname #f))
> +  (if (and record-name fieldname)
> +      (begin
> +        (display (string-append "<opensmtpd-" record-name ">
> fieldname " fieldname " "
> +                                (apply string-append %strings)))
> +        (throw 'bad! var))
> +      (begin
> +        (display (apply string-append %strings))
> +        (throw 'bad! var))))
> +
> +;; this is used for sanitizing <opensmtpd-filter-phase> fieldname
> 'options'
> +(define (contains-duplicate? list)
> +  (if (null? list)
> +      #f
> +      (or
> +      ;; check if (car list) is in (cdr list)
> +       (primitive-eval (cons 'or
> +                                (map (lambda (var) (equal? var (car
> list)))
> +                                     (cdr list))))
> +       ;; check if (cdr list) contains duplicate
> +       (contains-duplicate? (cdr list)))))
> +
> +;; given a list and procedure, this tests that each element of list
> is of type
> +;; ie: (list-of-type? list string?) tests each list is of type
> string.
> +(define (list-of-type? list proc?)
> +  (if (and (list? list)
> +           (not (null? list)))
> +      (let loop ((list list))
> +        (if (null? list)
> +            #t
> +            (if (proc? (car list))
> +                (loop (cdr list))
> +                #f)))
> +      #f))
> +
> +(define (list-of-strings? list)
> +  (list-of-type? list string?))
> +
> +(define (list-of-unique-opensmtpd-option? list)
> +  (and (list-of-type?
> +        list opensmtpd-option?)
> +       (not (contains-duplicate? list))))
> +
> +(define (list-of-opensmtpd-ca? list)
> +  (list-of-type? list opensmtpd-ca?))
> +
> +(define (list-of-opensmtpd-pki? list)
> +  (list-of-type? list opensmtpd-pki?))
> +
> +(define (list-of-opensmtpd-interface? list)
> +  (and (list-of-type? list opensmtpd-interface?)
> +       (not (contains-duplicate? list))))
> +
> +(define (list-of-unique-opensmtpd-match? list)
> +  (and (list-of-type? list opensmtpd-match?)
> +       (not (contains-duplicate? list))))
> +
> +(define* (list-of-strings->string list
> +                                  #:key
> +                                  (string-delimiter ", ")
> +                                  (postpend "")
> +                                  (append "")
> +                                  (drop-right-number 2))
> +  (string-drop-right
> +   (string-append (let loop ((list list))
> +                    (if (null? list)
> +                        ""
> +                        (string-append append (car list) postpend
> +                                       string-delimiter
> +                                       (loop (cdr list)))))
> +                  append)
> +   drop-right-number))
> +
> +;; at the moment I cannot define this by using list-of-type?
> +;; the first (not (null? assoc-list)) prevents that.
> +(define (assoc-list? assoc-list)
> +  (list-of-type? assoc-list (lambda (pair)
> +                              (if (and (pair? pair)
> +                                       (string? (car pair))
> +                                       (string? (cdr pair)))
> +                                  #t
> +                                  #f))))
> +
> +(define* (variable->string var #:key (append "") (postpend " "))
> +  (let ((var (if (number? var)
> +                 (number->string var)
> +                 var)))
> +    (if var
> +        (string-append append var postpend)
> +        "")))
> +
> +;; this procedure takes in one argument.
> +;; if that argument is an <opensmtpd-table> whose fieldname 'values'
> is an assoc-list, then it returns
> +;; #t, #f if otherwise.
> +;; TODO should I remove these two functions?  And instead use the
> (opensmtpd-table-type) procedure?
> +(define (table-whose-data-are-assoc-list? table)
> +  (if (not (opensmtpd-table? table))
> +      #f
> +      (assoc-list? (opensmtpd-table-data table))))
> +
> +;; this procedure takes in one argument
> +;; if that argument is an <opensmtpd-table> whose fieldname 'values'
> is a list of strings, then it returns
> +;; #t, #f if otherwise.
> +(define (table-whose-data-are-a-list-of-strings? table)
> +  (if (not (opensmtpd-table? table))
> +      #f
> +      (list-of-strings? (opensmtpd-table-data table))))
> +
> +;; these next few functions help me to turn <table>s
> +;; into strings suitable to fit into "opensmtpd.conf".
> +(define (assoc-list->string assoc-list)
> +  (string-drop-right
> +   (let loop ((assoc-list assoc-list))
> +     (if (null? assoc-list)
> +         ""
> +         ;; pair is (cons "hello" "world") -> ("hello" . "world")
> +         (let ((pair (car assoc-list)))
> +           (string-append
> +            "\"" (car pair)  "\""
> +            " = "
> +            "\"" (cdr pair) "\""
> +            ", "
> +            (loop (cdr assoc-list))))))
> +   2))
> +
> +;;  The following functions convert various records into strings.
> +;;
> +;; can be of type: (quote list-of-strings) or (quote assoc-list)
> +(define (opensmtpd-table->string table)
> +  (string-append "table " (opensmtpd-table-name table) " "
> +                 (let ((type (opensmtpd-table-type table)))
> +                   (cond ((eq? type (quote list-of-strings))
> +                          (string-append "{ " (list-of-strings-
> >string (opensmtpd-table-data table)
> +                                                                    
>    #:append "\""
> +                                                                    
>    #:drop-right-number 3
> +                                                                    
>    #:postpend "\"") " }"))
> +                         ((eq? type (quote assoc-list))
> +                          (string-append "{ " (assoc-list->string
> (opensmtpd-table-data table)) " }"))
> +                         ((eq? type (quote db))
> +                          (string-append "db:" (opensmtpd-table-data
> table)))
> +                         ((eq? type (quote file))
> +                          (string-append "file:" (opensmtpd-table-
> data table)))
> +                         (else (throw 'youMessedUp table))))
> +                 " \n"))
> +
> +(define (opensmtpd-interface->string record)
> +  (string-append "listen on "
> +                 (opensmtpd-interface-interface record) " "
> +                 (let* ((hostname (opensmtpd-interface-hostname
> record))
> +                        (hostnames (if (opensmtpd-interface-
> hostnames record)
> +                                       (opensmtpd-table-name
> (opensmtpd-interface-hostnames record))
> +                                       #f))
> +                        (filters (opensmtpd-interface-filters
> record))
> +                        (filter-name (if filters
> +                                         (if (< 1 (length filters))
> +                                             (generate-filter-chain-
> name filters)
> +                                             (if (opensmtpd-filter?
> (car filters))
> +                                                 (opensmtpd-filter-
> name (car filters))
> +                                                 (opensmtpd-filter-
> phase-name (car filters))))
> +                                         #f))
> +                        (mask-src (opensmtpd-interface-mask-src
> record))
> +                        (tag (opensmtpd-interface-tag record))
> +                        (secure-connection (opensmtpd-interface-
> secure-connection record))
> +                        (port (opensmtpd-interface-port record))
> +                        (pki (opensmtpd-interface-pki record))
> +                        (auth (opensmtpd-interface-auth record))
> +                        (auth-optional (opensmtpd-interface-auth-
> optional record)))
> +                   (string-append
> +                    (if mask-src
> +                        (string-append "mask-src ")
> +                        "")
> +                    (variable->string hostname #:append "hostname ")
> +                    (variable->string hostnames #:append "hostnames
> <" #:postpend "> ")
> +                    (variable->string filter-name #:append "filter
> \"" #:postpend "\" ")
> +                    (variable->string tag #:append "tag \""
> #:postpend "\" ")
> +                    (if secure-connection
> +                        (cond ((string=? "smtps" secure-connection)
> +                               "smtps ")
> +                              ((string=? "tls" secure-connection)
> +                               "tls ")
> +                              ((string=? "tls-require" secure-
> connection)
> +                               "tls-require ")
> +                              ((string=? "tls-require-verify"
> secure-connection)
> +                               "tls-require verify "))
> +                        "")
> +                    (variable->string port #:append "port "
> #:postpend " ")
> +                    (if pki
> +                        (variable->string (opensmtpd-pki-domain pki)
> #:append "pki ")
> +                        "")
> +                    (if auth
> +                        (string-append "auth "
> +                                       (if (opensmtpd-table? auth)
> +                                           (string-append "<"
> (opensmtpd-table-name auth) "> ")
> +                                           ""))
> +                        "")
> +                    (if auth-optional
> +                        (string-append "auth-optional "
> +                                       (if (opensmtpd-table? auth-
> optional)
> +                                           (string-append "<"
> (opensmtpd-table-name auth-optional) "> ")
> +                                           ""))
> +                        "")
> +                    "\n"))))
> +
> +(define (opensmtpd-socket->string record)
> +  (string-append "listen on socket "
> +                 (let* ((filters (opensmtpd-socket-configuration-
> filters record))
> +                        (filter-name (if filters
> +                                         (if (< 1 (length filters))
> +                                             (generate-filter-chain-
> name filters)
> +                                             (if (opensmtpd-filter?
> (car filters))
> +                                                 (opensmtpd-filter-
> name (car filters))
> +                                                 (opensmtpd-filter-
> phase-name (car filters))))
> +                                         #f))
> +                        (mask-src (opensmtpd-socket-configuration-
> mask-src record))
> +                        (tag (opensmtpd-socket-configuration-tag
> record)))
> +                   (string-append
> +                    (if mask-src
> +                        (string-append "mask-src ")
> +                        "")
> +                    (variable->string filter-name #:append "filter
> \"" #:postpend "\" ")
> +                    (variable->string tag #:append "tag \""
> #:postpend "\" ")
> +                    "\n"))))
> +
> +(define (opensmtpd-relay->string record)
> +  (let ((backup (opensmtpd-relay-backup record))
> +        (backup-mx (opensmtpd-relay-backup-mx record))
> +        (helo (opensmtpd-relay-helo record))
> +        ;; helo-src can either be a string IP address or an
> <opensmtpd-table>
> +        (helo-src (if (opensmtpd-relay-helo-src record)
> +                      (if (string? (opensmtpd-relay-helo-src
> record))
> +                          (opensmtpd-relay-helo-src record)
> +                          (string-append "<\""
> +                                         (opensmtpd-table-name
> +                                          (opensmtpd-relay-src
> record))
> +                                         "\">"))
> +                      #f))
> +        (domain (if (opensmtpd-relay-domain record)
> +                    (opensmtpd-table-name
> +                     (opensmtpd-relay-domain record))
> +                    #f))
> +        (host (opensmtpd-relay-host record))
> +        (name (opensmtpd-relay-name record))
> +        (pki (if (opensmtpd-relay-pki record)
> +                 (opensmtpd-pki-domain (opensmtpd-relay-pki record))
> +                 #f))
> +        (srs (opensmtpd-relay-srs record))
> +        (tls (opensmtpd-relay-tls record))
> +        (auth (if (opensmtpd-relay-auth record)
> +                  (opensmtpd-table-name
> +                   (opensmtpd-relay-auth record))
> +                  #f))
> +        (mail-from (opensmtpd-relay-mail-from record))
> +        ;; src can either be a string IP address or an <opensmtpd-
> table>
> +        (src (if (opensmtpd-relay-src record)
> +                 (if (string? (opensmtpd-relay-src record))
> +                     (opensmtpd-relay-src record)
> +                     (string-append "<\""
> +                                    (opensmtpd-table-name
> +                                     (opensmtpd-relay-src record))
> +                                    "\">"))
> +                 #f)))
> +        
> +    (string-append
> +     "\""
> +     name
> +     "\" " "relay "
> +     ;;FIXME should I always quote the host fieldname? do I need to
> quote localhost via "localhost" ?
> +     (variable->string host #:append "host \"" #:postpend "\" ")
> +     (variable->string backup)
> +     (variable->string backup-mx #:append "backup mx ")
> +     (variable->string helo #:append "helo ")
> +     (variable->string helo-src #:append "helo-src ")
> +     (variable->string domain #:append "domain <\"" #:postpend "\">
> ")
> +     (variable->string host #:append "host ")
> +     (variable->string pki #:append "pki ")
> +     (variable->string srs)
> +     (variable->string tls #:append "tls ")
> +     (variable->string auth #:append "auth <" #:postpend "> ")
> +     (variable->string mail-from #:append "mail-from ")
> +     (variable->string src #:append "src ")
> +     "\n")))
> +
> +(define (opensmtpd-lmtp->string record)
> +  (string-append "lmtp "
> +                 (opensmtpd-lmtp-destination record)
> +                 (if (opensmtpd-lmtp-rcpt-to record)
> +                     (begin
> +                       " " (opensmtpd-lmtp-rcpt-to record))
> +                     "")))
> +
> +(define (opensmtpd-mda->string record)
> +  (string-append "mda "
> +                 (opensmtpd-mda-command record) " "))
> +
> +(define (opensmtpd-maildir->string record)
> +  (string-append "maildir "
> +                 "\""
> +                 (if (opensmtpd-maildir-pathname record)
> +                     (opensmtpd-maildir-pathname record)
> +                     "~/Maildir")
> +                 "\""
> +                 (if (opensmtpd-maildir-junk record)
> +                     " junk "
> +                     " ")))
> +
> +(define (opensmtpd-local-delivery->string record)
> +  (let ((name (opensmtpd-local-delivery-name record))
> +        (method (opensmtpd-local-delivery-method record))
> +        (alias (if (opensmtpd-local-delivery-alias record)
> +                   (opensmtpd-table-name
> +                    (opensmtpd-local-delivery-alias record))
> +                   #f))
> +        (ttl (opensmtpd-local-delivery-ttl record))
> +        (user (opensmtpd-local-delivery-user record))
> +        (userbase (if (opensmtpd-local-delivery-userbase record)
> +                      (opensmtpd-table-name
> +                       (opensmtpd-local-delivery-userbase record))
> +                      #f))
> +        (virtual (if (opensmtpd-local-delivery-virtual record)
> +                     (opensmtpd-table-name
> +                      (opensmtpd-local-delivery-virtual record))
> +                     #f))
> +        (wrapper (opensmtpd-local-delivery-wrapper record)))
> +    (string-append
> +     "\"" name "\" "
> +     (cond ((string? method)
> +            (string-append method " "))
> +           ((opensmtpd-mda? method)
> +            (opensmtpd-mda->string method))
> +           ((opensmtpd-lmtp? method)
> +            (opensmtpd-lmtp->string method))
> +           ((opensmtpd-maildir? method)
> +            (opensmtpd-maildir->string method)))
> +     ;; FIXME/TODO support specifying alias file:/path/to/alias-
> file  ?
> +     ;; I do not think that is something that I can do...
> +     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
> +     (variable->string ttl #:append "ttl ")
> +     (variable->string user #:append "user ")
> +     (variable->string userbase #:append "userbase <\"" #:postpend
> "\"> ")
> +     (variable->string virtual #:append "virtual <" #:postpend "> ")
> +     (variable->string wrapper #:append "wrapper "))))
> +
> +;; this function turns both opensmtpd-local-delivery and
> +;; opensmtpd-relay into strings.
> +(define (opensmtpd-action->string record)
> +  (string-append "action "
> +                 (cond ((opensmtpd-local-delivery? record)
> +                        (opensmtpd-local-delivery->string record))
> +                       ((opensmtpd-relay? record)
> +                        (opensmtpd-relay->string record)))
> +                 " \n"))
> +
> +;; this turns option records found in <opensmtpd-match> into
> strings.
> +(define* (opensmtpd-option->string record
> +                                                 #:key
> +                                                 (space-after-! #f))
> +  (let ((not (opensmtpd-option-not record))
> +        (option (opensmtpd-option-option record))
> +        (regex (opensmtpd-option-regex record))
> +        (data (opensmtpd-option-data record)))
> +    (string-append
> +     (if not
> +         (if space-after-!
> +             "! "
> +             "!")
> +         "")
> +     option " "
> +     (if regex
> +         "regex "
> +         "")
> +     (if data
> +         (if (opensmtpd-table? data)
> +             (string-append "<" (opensmtpd-table-name data) "> ")
> +             (string-append data " "))
> +         ""))))
> +
> +(define (opensmtpd-match->string record)
> +  (string-append "match "
> +                 (let* ((action (opensmtpd-match-action record))
> +                        (name (cond [(opensmtpd-relay? action)
> +                                     (opensmtpd-relay-name action)]
> +                                    [(opensmtpd-local-delivery?
> action)
> +                                     (opensmtpd-local-delivery-name
> action)]
> +                                    [else 'reject]))
> +                        (options (opensmtpd-match-options record)))
> +                   (string-append
> +                    (if options
> +                        (apply string-append
> +                               (map opensmtpd-option->string
> options))
> +                        "")
> +                    (if (string? name)
> +                        (string-append "action " "\"" name "\" ")
> +                        "reject ")
> +                    "\n"))))
> +
> +(define (opensmtpd-ca->string record)
> +  (string-append "ca " (opensmtpd-ca-name record) " "
> +                 "cert \"" (opensmtpd-ca-file record) "\"\n"))
> +
> +(define (opensmtpd-pki->string record)
> +  (let ((domain (opensmtpd-pki-domain record))
> +        (cert (opensmtpd-pki-cert record))
> +        (key (opensmtpd-pki-key record))
> +        (dhe (opensmtpd-pki-dhe record)))
> +    (string-append "pki " domain " " "cert \"" cert "\" \n"
> +                   "pki " domain " " "key \"" key "\" \n"
> +                   (if dhe
> +                       (string-append
> +                        "pki " domain " " "dhe " dhe "\n")
> +                       ""))))
> +
> +(define (generate-filter-chain-name list-of-filters)
> +  (string-drop-right (apply string-append
> +                            (flatten
> +                             (map (lambda (filter)
> +                                    (list
> +                                     (if (opensmtpd-filter? filter)
> +                                         (opensmtpd-filter-name
> filter)
> +                                         (opensmtpd-filter-phase-
> name filter))
> +                                     "-"))
> +                                  list-of-filters)))
> +                     1))
> +
> +;; this procedure takes in a list of <opensmtpd-filter> and
> <opensmtpd-filter-phase>,
> +;; returns a string of the form:
> +;; filter "uniquelyGeneratedName" chain chain { "filter-name",
> "filter-name2" [, ...]}
> +(define (opensmtpd-filter-chain->string list-of-filters)
> +  (string-append "filter \""
> +                 (generate-filter-chain-name list-of-filters)
> +                 "\" "
> +                 "chain {"
> +                 (string-drop-right
> +                  (apply string-append
> +                         (flatten
> +                          (map (lambda (filter)
> +                                 (list
> +                                  "\""
> +                                  (if (opensmtpd-filter? filter)
> +                                      (opensmtpd-filter-name filter)
> +                                      (opensmtpd-filter-phase-name
> filter))
> +                                  "\", "))
> +                               list-of-filters)))
> +                  2)
> +                 "}\n"))
> +
> +(define (opensmtpd-filter-phase->string record)
> +  (let ((name (opensmtpd-filter-phase-name record))
> +        (phase (opensmtpd-filter-phase-phase record))
> +        (decision (opensmtpd-filter-phase-decision record))
> +        (options (opensmtpd-filter-phase-options record))
> +        (message (opensmtpd-filter-phase-message record))
> +        (value (opensmtpd-filter-phase-value record)))
> +    (string-append "filter "
> +                   "\"" name "\" "
> +                   "phase " phase " "
> +                   "match "
> +                   (apply string-append ; turn the options into a
> string
> +                          (flatten
> +                           (map (lambda (option)
> +                                  (opensmtpd-option->string option
> #:space-after-! #f))
> +                                options)))
> +                   " "
> +                   decision " "
> +                   (if (string-in-list? decision (list "reject"
> "disconnect"))
> +                       (string-append "\"" message "\"")
> +                       "")
> +                   (if (string=? "rewrite" decision)
> +                       (string-append "rewrite " (number->string
> value))
> +                       "")
> +                   "\n")))
> +
> +;; filters elements may be <opensmtpd-filter>, <opensmtpd-filter-
> phase>,
> +;; and lists that look like (list (opensmtpd-filter...) (opensmtpd-
> filter-phase ...)
> +;; ...)
> +;; this function converts it to a string.
> +;; Consider if a user passed in a valid <opensmtpd-configuration>,
> whose total valid filters
> +;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
> +;; look like this: (we will call this list "total filters"):
> +;; (list (opensmtpd-filter
> +;;         (name "rspamd")
> +;;         (proc "rspamd"))
> +;;       (list (opensmtpd-filter-phase ; this is a listen-on, with a
> filter-chain.
> +;;               (name "dkimsign")
> +;;               ...)
> +;;               (opensmtpd-filter
> +;;                 (name "rspamd")
> +;;                 (proc "rspamd"))))
> +;;
> +;; did you notice that filter "rspamd" is listed twice?  How do you
> make sure that it is NOT
> +;; printed twice in smtpd.conf?
> +;; 1st flatten "total filters", then remove its duplicates.  Then
> print all of those filters.
> +;; 2nd now we go through "total filters", and we only print the non-
> filter-chains.
> +(define (opensmtpd-filters->list-of-strings-and-gexps filters)
> +  ;; first display the unique <opensmtpd-filter>s. and <opensmtpd-
> filter-phase>s.
> +  ;; to do this: flatten filters, then remove duplicates.
> +  (list
> +   (apply string-append
> +          (map (lambda (filter)
> +                 (if (opensmtpd-filter-phase? filter)
> +                     (opensmtpd-filter-phase->string filter)
> +                     ""))
> +               (delete-duplicates (flatten filters))))
> +   ;; print out the filter-configurations
> +   ;; would values and or call-with-values and or recieve work here?
> +   (list (map (lambda (filter)
> +                (if (opensmtpd-filter? filter)
> +                    (list "filter "
> +                          "\"" (opensmtpd-filter-name filter) "\" "
> +                          (if (opensmtpd-filter-exec filter)
> +                              "proc-exec "
> +                              "proc ")
> +                          "\"" (opensmtpd-filter-proc filter) "\""
> +                          "\n\n")
> +                    ""))
> +              (delete-duplicates (flatten filters))))
> +   ;; now we have to print the filter chains.
> +   (apply string-append
> +          (map (lambda (filter)
> +                 (cond ((list? filter)
> +                        (opensmtpd-filter-chain->string filter))
> +                       (else      ; you are a <opensmtpd-filter>
> +                        "")))
> +               filters))))
> +
> +(define (opensmtpd-configuration-listen->string string)
> +  (string-append
> +   "include \"" string "\"\n"))
> +
> +(define (opensmtpd-configuration-srs->string record)
> +  (let ((key (opensmtpd-srs-key record))
> +        (backup-key (opensmtpd-srs-backup-key record))
> +        (ttl-delay (opensmtpd-srs-ttl-delay record)))
> +    (string-append
> +     (variable->string key #:append "srs key " #:postpend "\n")
> +     (variable->string backup-key #:append "srs key backup "
> #:postpend "\n")
> +     (variable->string ttl-delay #:append "srs ttl " #:postpend
> "\n")
> +     "\n")))
> +
> +;; TODO make sure all options here work!  I just fixed limit-max-
> rcpt!
> +(define (opensmtpd-smtp->string record)
> +  (let ((ciphers (opensmtpd-smtp-ciphers record))
> +        (limit-max-mails (opensmtpd-smtp-limit-max-mails record))
> +        (limit-max-rcpt (opensmtpd-smtp-limit-max-rcpt record))
> +        (max-message-size (opensmtpd-smtp-max-message-size record))
> +        (sub-addr-delim (opensmtpd-smtp-sub-addr-delim record)))
> +    (string-append
> +     (variable->string ciphers #:append "smtp ciphers " #:postpend
> "\n")
> +     (variable->string limit-max-mails #:append "smtp limit max-
> mails " #:postpend "\n")
> +     (variable->string limit-max-rcpt #:append "smtp limit max-rcpt
> " #:postpend "\n")
> +     (variable->string max-message-size #:append "smtp max-message-
> size " #:postpend "\n")
> +     (variable->string sub-addr-delim #:append "smtp sub-addr-delim
> " #:postpend "\n")
> +     "\n")))
> +
> +(define (opensmtpd-configuration-queue->string record)
> +  (let ((compression (opensmtpd-queue-compression record))
> +        (encryption (opensmtpd-queue-encryption record))
> +        (ttl-delay (opensmtpd-queue-ttl-delay record)))
> +    (string-append
> +     (if compression
> +         "queue compression\n"
> +         "")
> +     (if encryption
> +         (string-append
> +          "queue encryption "
> +          (if (not (boolean? encryption))
> +              encryption
> +              "")
> +          "\n")
> +         "")
> +     (if ttl-delay
> +         (string-append "queue ttl" ttl-delay "\n")
> +         ""))))
> +
> +;; build a list of <opensmtpd-action> from
> +;; opensmtpd-configuration-matches, which is a list of <opensmtpd-
> match>.
> +;; Each <opensmtpd-match> has a fieldname 'action', which accepts an
> <opensmtpd-action>.
> +(define (get-opensmtpd-actions record)
> +  (define opensmtpd-actions
> +    (let loop ((list (opensmtpd-configuration-matches record)))
> +      (if (null? list)
> +          '()
> +          (cons (opensmtpd-match-action (car list))
> +                (loop (cdr list))))))
> +  (delete-duplicates (append opensmtpd-actions)))
> +
> +;; build a list of opensmtpd-pkis from
> +;; opensmtpd-configuration-listen-ons and
> +;; get-opensmtpd-actions
> +(define (get-opensmtpd-pkis record)
> +  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT
> have an opensmtpd-relay?
> +  ;; I think so.  And if it did NOT have a relay configuration, then
> action-pkis would be '() when
> +  ;; it needs to be #f.  because if the opensmtpd-configuration has
> NO pkis, then this function will
> +  ;; return '(), when it should return #f.  If it returns '(), then
> opensmtpd-configuration-fieldname->string will
> +  ;; print the string "\n" instead of ""
> +  (define action-pkis
> +    (let loop1 ((list (get-opensmtpd-actions record)))
> +      (if (null? list)
> +          '()
> +          (if (and (opensmtpd-relay? (car list))
> +                   (opensmtpd-relay-pki (car list)))
> +              (cons (opensmtpd-relay-pki (car list))
> +                    (loop1 (cdr list)))
> +              (loop1 (cdr list))))))
> +  ;; FIXME/TODO/maybe/wishlist
> +  ;; this could be #f aka left blank. aka there are no listen-ons
> records with pkis.
> +  ;; aka there are no lines in the configuration like:
> +  ;; listen on eth0 tls pki smtp.gnucode.me in that case the
> smtpd.conf will have an extra "\n"
> +  (define listen-on-pkis
> +    (let loop2 ((list (opensmtpd-configuration-listen-ons record)))
> +      (if (null? list)
> +          '()
> +          (if (opensmtpd-interface-pki (car list))
> +              (cons (opensmtpd-interface-pki (car list))
> +                    (loop2 (cdr list)))
> +              (loop2 (cdr list))))))
> +  (delete-duplicates (append action-pkis listen-on-pkis)))
> +
> +;; takes in a <opensmtpd-configuration> and returns a list whose
> elements are <opensmtpd-filter>,
> +;; <opensmtpd-filter-phase>, and a filter-chain.
> +;; It returns a list of <opensmtpd-filter> and/or <opensmtpd-filter-
> phase>
> +;; here's an example of what this procedure might return:
> +;; (list (opensmtpd-filter...) (opensmtpd-filter-phase ...)
> +;;       (openmstpd-filter ...) (opensmtpd-filter-phase ...)
> +;;       ;; this next list is a filter-chain.
> +;;       (list (opensmtpd-filter-phase ...) (opensmtpd-filter...)))
> +;;
> +;; This procedure handles filter chains a little odd.
> +(define (get-opensmtpd-filters record)
> +  (define list-of-listen-on-records (if (opensmtpd-configuration-
> listen-ons record)
> +                                        (opensmtpd-configuration-
> listen-ons record)
> +                                        '()))
> +
> +  (define listen-on-socket-filters
> +    (if (opensmtpd-socket-configuration-filters (opensmtpd-
> configuration-listen-on-socket record))
> +        (opensmtpd-socket-configuration-filters (opensmtpd-
> configuration-listen-on-socket record))
> +        '()))
> +
> +  (delete-duplicates
> +   (append (remove boolean?
> +                   (map-in-order (lambda (listen-on-record) ; get
> the filters found in the <listen-on-record>s
> +                                   (if (and (opensmtpd-interface-
> filters listen-on-record)
> +                                            (= 1 (length (opensmtpd-
> interface-filters
> +                                                          listen-on-
> record))))
> +                                       (car (opensmtpd-interface-
> filters listen-on-record))
> +                                       (opensmtpd-interface-filters
> listen-on-record)))
> +                                 list-of-listen-on-records))
> +           listen-on-socket-filters)))
> +
> +(define (flatten . lst)
> +  "Return a list that recursively concatenates all sub-lists of
> LST."
> +  (define (flatten1 head out)
> +    (if (list? head)
> +        (fold-right flatten1 out head)
> +        (cons head out)))
> +  (fold-right flatten1 '() lst))
> +
> +;; This function takes in a record, or list, or anything, and
> returns
> +;; a list of <opensmtpd-table>s assuming the thing you passed into
> it had
> +;; any <opensmtpd-table>s.
> +;;
> +;; is object record? call func on it's fieldnames
> +;; is object list? loop through it's fieldnames calling func on it's
> records
> +;; is object #f or string? or '()? -> #f
> +(define (get-opensmtpd-tables value)
> +  (delete-duplicates
> +   (remove boolean? (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2
> 3)
> +                     (cond ((opensmtpd-table? value)
> +                            value)
> +                           ((record? value)
> +                            (let* ((record-type (record-type-
> descriptor value))
> +                                   (list-of-record-fieldnames
> (record-type-fields record-type)))
> +                              (map (lambda (fieldname)
> +                                     (get-opensmtpd-tables ((record-
> accessor record-type fieldname) value)))
> +                                   list-of-record-fieldnames)))
> +                           ((and (list? value) (not (null? value)))
> +                            (map get-opensmtpd-tables value))
> +                           (else #f))))))
> +
> +(define (opensmtpd-configuration-fieldname->string record fieldname-
> accessor record->string)
> +  (if (fieldname-accessor record)
> +      (begin
> +        (string-append
> +         (list-of-records->string (fieldname-accessor record)
> record->string) "\n"))
> +      ""))
> +
> +(define (list-of-records->string list-of-records record->string)
> +  (string-append
> +   (cond ((not (list? list-of-records))
> +          (record->string list-of-records))
> +         (else
> +          (let loop ([list list-of-records])
> +            (if (null? list)
> +                ""
> +                (string-append
> +                 (record->string (car list))
> +                 (loop (cdr list)))))))))
> +
> +(define (opensmtpd-configuration->string record)
> +  (string-append
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-bounce
> +                                              (lambda (%bounce)
> +                                                (if %bounce
> +                                                    (list-of-
> strings->string %bounce)
> +                                                    "")))
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-smtp
> +                                              opensmtpd-smtp-
> >string)
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-srs
> +                                              opensmtpd-
> configuration-srs->string)
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-queue
> +                                              opensmtpd-
> configuration-queue->string)
> +   ;; write out the mta-max-deferred
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-mta-max-deferred
> +    (lambda (var)
> +      (string-append "mta max-deferred "
> +                     (number->string (opensmtpd-configuration-mta-
> max-deferred record)) "\n")))
> +   ;;write out all the tables
> +   (opensmtpd-configuration-fieldname->string record get-opensmtpd-
> tables opensmtpd-table->string)
> +   ;; write out all the cas
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-cas opensmtpd-ca->string)
> +   ;; write out all the pkis
> +   (opensmtpd-configuration-fieldname->string record get-opensmtpd-
> pkis opensmtpd-pki->string)
> +   ;; write all of the listen-on-records
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-listen-ons
> +                                              opensmtpd-interface-
> >string)
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-listen-on-socket
> +                                              opensmtpd-socket-
> >string)
> +   ;; write all the actions
> +   (opensmtpd-configuration-fieldname->string record get-opensmtpd-
> actions
> +                                              opensmtpd-action-
> >string)
> +   ;; write all of the matches
> +   (opensmtpd-configuration-fieldname->string record opensmtpd-
> configuration-matches opensmtpd-match->string)))
> +
> +;; FIXME/TODO should I use format here srfi-28 ?
> +;; web.scm nginx does a (format #f "string" "another string")
> +;; this could be a list like (list (file-append opensmtpd-dkimsign
> "/libexec/filter") "-d gnucode.me -s /path/to/selector.cert")
> +;; Then opensmtpd-configuration->mixed-text-file could be rewritten
> to be something like
> +;; (mixed-text-file (eval `(string-append (opensmtpd-configuration-
> fieldname->string ...)) (gnu services mail)))
> +(define (opensmtpd-configuration->mixed-text-file record)
> +  ;; should I use this named let, or should I give this a name, or
> not use it at all...
> +  ;; eg: (write-all-fieldnames (list (cons fieldname fieldname-
> >string) (cons fieldname2 fieldname->string)))
> +  ;; (let loop ([list (list (cons opensmtpd-configuration-includes
> (lambda (string)
> +  ;;                                                                
> (string-append
> + 
> ;;                                                                 
> "include \"" string "\"\n")))
> +  ;;                        (cons opensmtpd-configuration-smtp
> opensmtpd-smtp->string)
> +  ;;                        (cons opensmtpd-configuration-srs
> opensmtpd-srs->string))])
> +  ;;   (if (null? list)
> +  ;;       ""
> +  ;;       (string-append (opensmtpd-configuration-fieldname->string
> record
> +  ;;                                                                
> (caar list)
> +  ;;                                                                
> (cdar list))
> +  ;;                      (loop (cdr list)))))
> +
> +  (apply mixed-text-file "smtpd.conf"
> +         ;; write out the includes
> +         (flatten (list
> +                   (opensmtpd-configuration-fieldname->string record
> opensmtpd-configuration-includes
> +                                                             
> opensmtpd-configuration-listen->string)
> +                   ;; TODO should I change the below line of code
> into these two lines of code?
> +                   ;;(opensmtpd-configuration-fieldname->string
> record get-opensmtpd-filters-and-filter-phases opensmtpd-filter-and-
> filter-phase->string)
> +                   ;;(opensmtpd-configuration-fieldname->string
> record get-opensmtpd-filter-chains opensmtpd-filter-chain->string)
> +                   ;; write out all the filters
> +                   (opensmtpd-filters->list-of-strings-and-gexps
> (get-opensmtpd-filters record))
> +                   (opensmtpd-configuration->string record)))))
> +
> +
>  (define %default-opensmtpd-config-file
>    (plain-file "smtpd.conf" "
>  listen on lo
> @@ -1668,7 +3724,7 @@ (define %default-opensmtpd-config-file
>  match from local for any action outbound
>  "))
>  
> -(define opensmtpd-shepherd-service
> +(define (opensmtpd-shepherd-service config)
>    (match-lambda
>      (($ <opensmtpd-configuration> package config-file)
>       (list (shepherd-service
> @@ -1677,7 +3733,8 @@ (define opensmtpd-shepherd-service
>              (documentation "Run the OpenSMTPD daemon.")
>              (start (let ((smtpd (file-append package
> "/sbin/smtpd")))
>                       #~(make-forkexec-constructor
> -                        (list #$smtpd "-f" #$config-file)
> +                        (list #$smtpd "-f" (or #$config-file
> +                                               #$(opensmtpd-
> configuration->mixed-text-file config)))
>                          #:pid-file "/var/run/smtpd.pid")))
>              (stop #~(make-kill-destructor)))))))
>  
> @@ -1700,10 +3757,11 @@ (define %opensmtpd-accounts
>           (home-directory "/var/empty")
>           (shell (file-append shadow "/sbin/nologin")))))
>  
> -(define opensmtpd-activation
> +(define (opensmtpd-activation config)
>    (match-lambda
>      (($ <opensmtpd-configuration> package config-file)
> -     (let ((smtpd (file-append package "/sbin/smtpd")))
> +     (let ((smtpd (file-append package "/sbin/smtpd"))
> +           (configuration (opensmtpd-configuration->mixed-text-file
> config)))
>         #~(begin
>             (use-modules (guix build utils))
>             ;; Create mbox and spool directories.
> @@ -1711,7 +3769,12 @@ (define opensmtpd-activation
>             (mkdir-p "/var/spool/smtpd")
>             (chmod "/var/spool/smtpd" #o711)
>             (mkdir-p "/var/spool/mail")
> -           (chmod "/var/spool/mail" #o711))))))
> +           (chmod "/var/spool/mail" #o711)
> +           (display (string-append "checking syntax of "
> +                                   (or
> +                                    #$config-file
> +                                    #$configuration)
> +                                   "\n")))))))
>  
>  (define %opensmtpd-pam-services
>    (list (unix-pam-service "smtpd")))
> diff --git a/gnu/tests/mail.scm b/gnu/tests/mail.scm
> index f13751b72f..1bac9f50a2 100644
> --- a/gnu/tests/mail.scm
> +++ b/gnu/tests/mail.scm
> @@ -37,6 +37,7 @@ (define-module (gnu tests mail)
>    #:use-module (guix gexp)
>    #:use-module (guix store)
>    #:use-module (ice-9 ftw)
> +  #:use-module (srfi srfi-64)
>    #:export (%test-opensmtpd
>              %test-exim
>              %test-dovecot
> @@ -165,6 +166,360 @@ (define %test-opensmtpd
>     (description "Send an email to a running OpenSMTPD server.")
>     (value (run-opensmtpd-test))))
>  
> +;; trying to create a bad record, should result in an error.
> +;; this function should be able return, instead it should throw an
> error
> +(define (create-bad-record record)
> +  ;; TODO why is this not working
> +  (with-output-to-port (%make-void-port "w")
> +    (lambda () (when record #f))))
> +
> +;; if this caller function is reached, then trying to create the bad
> record
> +;; resulted in an error.  So return true.
> +(define (return-true error arg)
> +  #t)
> +
> +;; two filters with the same name
> +(define (bad-interface1)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (interface "lo")
> +    (filters (list
> +              (opensmtpd-filter
> +               (name "dkimsign")
> +               (exec #t)
> +               (proc (list (file-append opensmtpd-filter-dkimsign
> "/libexec/opensmtpd/filter-dkimsign")
> +                           " -d gnucode.me -s 2021-09-22 -c
> relaxed/relaxed -k "
> +                           "rando string"
> +                           "/etc/dkim/private.key "
> +                           "user nobody group nogroup")))
> +              (opensmtpd-filter
> +               (name "dkimsign")
> +               (exec #t)
> +               (proc (list (file-append opensmtpd-filter-dkimsign
> "/libexec/opensmtpd/filter-dkimsign")
> +                           " -d gnucode.me -s 2021-09-22 -c
> relaxed/relaxed -k "
> +                           "/etc/dkim/private.key "
> +                           "user nobody group nogroup"))))))))
> +
> +;; duplicate filter names
> +(define (bad-interface2)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (filters (list
> +              (opensmtpd-filter-phase
> +               (name "src")
> +               (phase "connect")
> +               (options
> +                (list
> +                 (opensmtpd-option
> +                  (option "fcrdns")
> +                  (not #t))))
> +               (decision "junk"))
> +              (opensmtpd-filter-phase
> +               (name "src")
> +               (phase "helo")
> +               (options
> +                (list
> +                 (opensmtpd-option
> +                  (option "rdns")
> +                  (not #t))))
> +               (decision "junk")))))))
> +
> + ;; improper phase name
> +(define (bad-filter-phase1)
> +    (create-bad-record
> +     (opensmtpd-filter-phase
> +      (name "filter")
> +      (phase "wrongString")
> +      (decision "bypass")
> +      (options
> +       (list
> +        (opensmtpd-option
> +         (option "auth")))))))
> +
> +;; decision reject requires you to have a
> +;; corresponding fieldname 'message' with value of string.
> +(define (bad-filter-phase2)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (filters (list
> +              (opensmtpd-filter-phase
> +               (name "src")
> +               (phase "connect")
> +               (options
> +                (list
> +                 (opensmtpd-option
> +                  (option "src")
> +                  (data (opensmtpd-table
> +                         (name "src-table")
> +                         (data (list "cat" "hat")))))))
> +               (decision "reject")))))))
> +
> +;; message needs to start with 4xx or 5xx
> +(define (bad-filter-phase3)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (filters (list
> +              (opensmtpd-filter-phase
> +               (name "src")
> +               (phase "connect")
> +               (options
> +                (list
> +                 (opensmtpd-option
> +                  (option "src")
> +                  (data (opensmtpd-table
> +                         (name "src-table")
> +                         (data (list "cat" "hat")))))))
> +               (decision "reject")
> +               (message "322 Bad data!")))))))
> +
> + ;; there needs to be a value here.  rewrite requires a value!
> +(define (bad-filter-phase4)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (filters
> +     (list
> +      (opensmtpd-filter-phase
> +       (name "noFRDNS")
> +       (phase "commit")
> +       (options (list (opensmtpd-option
> +                       (option "fcrdns")
> +                       (not #t))))
> +       (decision "rewrite"))
> +      )))))
> +
> +;; fieldname 'decision' with value "junk" or "bypass", then
> fieldname 'message' and 'value'
> +;; must NOT be defined
> +(define (bad-filter-phase5)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (filters
> +     (list
> +      (opensmtpd-filter-phase
> +       (name "noFRDNS")
> +       (phase "commit")
> +       (options (list (opensmtpd-option
> +                       (option "fcrdns")
> +                       )))
> +       (decision "junk")
> +       (message "This is not a good email.")))))))
> +
> +;; you cannot junk on phase commit.  You need to use an eariler
> phase.
> +(define (bad-filter-phase6)
> +  (create-bad-record
> +   (opensmtpd-interface
> +    (filters
> +     (list
> +      (opensmtpd-filter-phase
> +       (name "junk-after-commit")
> +       (options (list (opensmtpd-option
> +                       (option "fcrdns"))))
> +       (phase "commit")
> +       (decision "junk")))))))
> +
> +;; TODO fix this test
> +;; two fcrdns options records
> +(define (bad-filter-phase7)
> +  (create-bad-record
> +   (opensmtpd-filter-phase
> +    (name "invalid-fcrdns")
> +    (phase "connect")
> +    (options
> +     (list (opensmtpd-option
> +            (option "fcrdns")
> +            (not #t))
> +           (opensmtpd-option
> +            (option "fcrdns")
> +            (not #f))))
> +    (decision "reject")
> +    (message "422 No valid fcrdns."))))
> +
> +;; option src requires a table
> +;; TODO maybe check for other options requiring a table
> +(define (bad-filter-phase8)
> +  (create-bad-record
> +   (opensmtpd-filter-phase
> +    (name "filter")
> +    (phase "helo")
> +    (decision "bypass")
> +    (options
> +     (list
> +      (opensmtpd-option
> +       (option "src")))))))
> +
> +;; option fcrdns cannot have data defined.
> +(define (bad-filter-phase9)
> +  (create-bad-record
> +   (opensmtpd-filter-phase
> +    (name "filter")
> +    (phase "helo")
> +    (decision "bypass")
> +    (options
> +     (list
> +      (opensmtpd-option
> +       (option "fcrdns")
> +       (data (opensmtpd-table
> +               (name "table")
> +               (data (list "hello" "cat"))))))))))
> +
> +
> +;; this should be (list ...) instead of '( ...)
> +(define (bad-match1)
> +  (create-bad-record
> +   (opensmtpd-match
> +    (options
> +     '((opensmtpd-option
> +        (option "for any"))))
> +    (action
> +     (opensmtpd-relay)))))
> +
> +
> +;; duplcate "for" options
> +(define (bad-match2)
> +  (create-bad-record
> +   (opensmtpd-match
> +            (options (list
> +                      (opensmtpd-option
> +                       (option "for any"))
> +                      (opensmtpd-option
> +                       (option "for local"))))
> +            (action
> +             (opensmtpd-relay
> +              (name "relay"))))))
> +
> +;; duplicate froms
> +(define (bad-match3)
> +  (create-bad-record
> +   (opensmtpd-match
> +    (options (list
> +              (opensmtpd-option
> +               (option "from any"))
> +              (opensmtpd-option
> +               (option "from auth"))))
> +    (action
> +     (opensmtpd-relay
> +      (name "relay"))))))
> +
> +;; rcpt-to must have a data field.
> +(define (bad-match4)
> +  (create-bad-record
> +   (opensmtpd-match
> +    (options (list
> +              (opensmtpd-option
> +               (option "rcpt-to"))))
> +    (action
> +     (opensmtpd-relay
> +      (name "relay"))))))
> +
> +;; option 'tls' cannot have fieldname
> +;; 'data' defined.
> +(define (bad-match5)
> +  (create-bad-record
> +   (opensmtpd-match
> +    (options (list
> +              (opensmtpd-option
> +               (option "tls")
> +               (data "hello"))))
> +    (action
> +     (opensmtpd-relay
> +      (name "relay"))))))
> +
> +;; for any cannot have data
> +;; or regex defined
> +(define (bad-match6)
> +  (create-bad-record
> +   (opensmtpd-match
> +    (options (list
> +              (opensmtpd-option
> +               (option "for any")
> +               (regex #t))))
> +    (action
> +     (opensmtpd-relay
> +      (name "relay"))))))
> +
> +;; match needs an action
> +(define (bad-match7)
> +  (create-bad-record
> +   (opensmtpd-match
> +    (options (list
> +              (opensmtpd-option
> +               (option "from auth")))))))
> +
> +(define (run-opensmtpd-record-sanitation-test)
> +                                        ;(with-output-to-port
> (%make-void-port "w")
> +                                        ;  (lambda ()
> +  (test-begin "run-opensmtpd-record-sanitation-test")
> +
> +  ;; TODO fix me!
> +  (test-assert "Test <interface> fieldname 'filters' has two filters
> with the same name."
> +    (catch #t bad-interface1 return-true))
> +
> +  (test-assert "Test <interface> cannot have two filters with the
> same name."
> +               (catch #t bad-interface2 return-true))
> +
> +  (test-assert "Test <filter-phase> fieldname 'phase' the right
> string."
> +    (catch #t bad-filter-phase1 return-true))
> +
> +  (test-assert "Test <filter-phase> fieldname 'decision' w/ value
> \"reject\" and \"disconnect\" requires a 'message'."
> +    (catch #t bad-filter-phase2 return-true))
> +
> +  (test-assert (string-append  "Test <filter-phase> fieldname
> 'decision' "
> +                               "w/ value \"reject\" and
> \"disconnect\" requires a 'message'."
> +                               " The message must begin with 4xx or
> 5xx.")
> +    (catch #t bad-filter-phase3 return-true))
> +
> +  (test-assert "Test <filter-phase> fieldname 'rewrite' requires
> fieldname 'value' to have a number."
> +    (catch #t bad-filter-phase4 return-true))
> +
> +  (test-assert (string-append "Test <filter-phase> fieldname
> 'decision' with values 'junk' or 'bypass', "
> +                             "then fieldname 'message' and 'value'
> must be blank.")
> +    (catch #t bad-filter-phase5 return-true))
> +
> +  (test-assert "You cannot junk an email on phase commit."
> +    (catch #t bad-filter-phase6 return-true))
> +
> +  ;; TODO fix me!
> +  (test-assert "Test <filter-phase> has 2 duplicate options."
> +    (catch #t bad-filter-phase7 return-true))
> +
> +  (test-assert "Test <filter-phase> option 'src' requires a table."
> +    (catch #t bad-filter-phase8 return-true))
> +
> +  ;; TODO fix me!
> +  (test-assert "Test <filter-phase> option 'fcrdns' cannot have a
> table."
> +    (catch #t bad-filter-phase9 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> fieldname 'options' should
> not be quoted."
> +    (catch #t bad-match1 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> has duplicate 'for' options."
> +    (catch #t bad-match2 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> has duplicate 'from'
> options."
> +    (catch #t bad-match3 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> option 'rcpt' must have
> data."
> +    (catch #t bad-match4 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> option 'tls' cannot have
> fieldname 'data' defined."
> +    (catch #t bad-match5 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> option 'for any' cannot have
> fieldname 'data' defined."
> +    (catch #t bad-match6 return-true))
> +
> +  (test-assert "Test <opensmtpd-match> needs fieldname 'action'
> needs to be defined."
> +    (catch #t bad-match7 return-true))
> +
> +  (test-end "run-opensmtpd-record-sanitation-test"))
> +
> +(define %test-opensmtpd-record-sanitation
> +  (system-test
> +   (name "opensmtpdRecordSanitation")
> +   (description
> +    (string-append "<opensmtpd> has numerous sanity checks.\n"
> +                   "This checks that invalid configurations, return
> an\n"
> +                   "appropriate error.\n"))
> +   (value (run-opensmtpd-record-sanitation-test))))
> +
>  
>  (define %exim-os
>    (simple-operating-system
> 
> base-commit: 4b3493ed0156709a924f31ef4c9a5efa0815dfe8

Cheers

^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [Patch master v2] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-10-24 17:30 ` [bug#56046] [Patch master v2] services (opensmtpd): " Joshua Branson via Guix-patches via
  2022-10-24 18:28   ` Liliana Marie Prikler
@ 2022-10-24 22:18   ` jbranso--- via Guix-patches via
  1 sibling, 0 replies; 23+ messages in thread
From: jbranso--- via Guix-patches via @ 2022-10-24 22:18 UTC (permalink / raw)
  To: Liliana Marie Prikler, 56046

October 24, 2022 2:29 PM, "Liliana Marie Prikler" <liliana.prikler@gmail.com> wrote:

> Am Montag, dem 24.10.2022 um 13:30 -0400 schrieb Joshua Branson:
> 
> Cheers

Thanks for the speedy response and quick review!

I also forgot to mention that the service is actually fairly use-able now!

<opensmtpd-filter> takes in a list of strings and gexps.  With a little
work you can use s-expressions to configure dkimsigning.

And it should be possible to integrate bogofilter, but I have not figured
that out yet.....


Thanks,

Joshua




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH opensmtpd-records v3] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-10-24 18:28   ` Liliana Marie Prikler
@ 2022-12-23 13:52     ` Joshua Branson via Guix-patches via
  2022-12-26 19:34       ` Liliana Marie Prikler
  0 siblings, 1 reply; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-12-23 13:52 UTC (permalink / raw)
  To: 56046; +Cc: liliana.prikler, Joshua Branson

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain; charset=y, Size: 184956 bytes --]

From: Joshua Branson <jbranso@dismail.de>

This is V3 of my opensmtp records configuration. Hopefully soon, I will have
this WIP service is guixrus, so more people can easily play with it.

https://git.sr.ht/~whereiseveryone/guixrus

BUT the new milestone is this, I am now actually able to use opensmtpd on my
gnucode.me account! So that is pretty awesome!

Here is a link to my server config:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/linode-locke-lamora-current-config.scm

The best place to find documentation for this service is here:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd-records-documentation.txt


Openmstpd-configuration may only be configured by a config-file that
uses the smtpd.conf syntax.  This patch, enables one to configure
opensmtpd by using record types.

* gnu/services/mail.scm:
(opensmtpd-table,
opensmtpd-ca,
opensmtpd-pki,
opensmtpd-action-local-delivery,
opensmtpd-maildir,
opensmtpd-mda,
opensmtpd-lmtp,
opensmtpd-relay,
opensmtpd-option,
opensmtpd-filter-phase,
opensmtpd-filter,
opensmtpd-interface,
opensmtpd-socket,
opensmtpd-match,
opensmtpd-smtp,
opensmtpd-srs,
opensmtpd-queue, and
opensmtpd-configuration): New records.

(false?, is-value-right-type, add-comma-or-string,
list-of-procedures->string, string-in-list?, my-sanitize,
opensmtpd-filter-chain?, throw-error-duplicate-option,
sanitize-list-of-options-for-match, sanitize-filters,
list-has-duplicates-or-non-filters?,
filter-phase-has-message-and-value?,
filter-phase-decision-lacks-proper-message?,
filter-phase-lacks-proper-value?,
filter-phase-has-incorrect-junk-or-bypass?,
filter-phase-junks-after-commit?,
list-of-unique-filter-or-filter-phase?, throw-error,
contains-duplicate?, list-of-type?, list-of-strings?,
list-of-unique-opensmtpd-option?,
list-of-opensmtpd-ca?,
list-of-opensmtpd-pki?,
list-of-opensmtpd-listen-on?,
list-of-unique-opensmtpd-match?, list-of-strings->string,
assoc-list? assoc-list, variable->string,
tables-data-are-assoc-list?,
tables-data-are-a-list-of-strings?,
table-data-are-a-nested-list-of-strings?,
assoc-list->string,
opensmtpd-table->string,
opensmtpd-listen-on->string,
opensmtpd-listen-on-socket->string,
opensmtpd-action-relay->string,
opensmtpd-lmtp->string,
opensmtpd-mda->string,
opensmtpd-maildir->string,
opensmtpd-action-local-delivery->string,
opensmtpd-action->string, opensmtpd-option->string,
opensmtpd-match->string,
opensmtpd-ca->string, opensmtpd-pki->string,
generate-filter-chain-name, opensmtpd-filter-chain->string,
opensmtpd-filter-phase->string, opensmtpd-filters->string,
opensmtpd-listen->string,
opensmtpd-srs->string,
opensmtpd-smtp->string,
opensmtpd-queue->string, get-opensmtpd-actions,
get-opensmtpd-pkis, get-opensmtpd-filters, flatten,
get-opensmtpd-tables, opensmtpd-fieldname->string,
list-of-records->string, opensmtpd->mixed-text-file): New
procedures.

* gnu/tests/mail.scm : new tests for various opensmtpd records.

* doc/guix.texi (OpenSMTPD Service): Added documentation for the
new records for opensmtpd.
---
 doc/guix.texi         | 1065 ++++++++++++++++-
 gnu/services/mail.scm | 2560 ++++++++++++++++++++++++++++++++++++++++-
 gnu/tests/mail.scm    |  713 ++++++++++++
 3 files changed, 4310 insertions(+), 28 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 535c8cdfc3..879a2ad233 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -25407,16 +25407,66 @@ could instantiate a dovecot service like this:
 @end lisp
 
 @subsubheading OpenSMTPD Service
+@cindex opensmtpd
 
 @deffn {Scheme Variable} opensmtpd-service-type
-This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
-service, whose value should be an @code{opensmtpd-configuration} object
-as in this example:
+OpenSMTPD is an easy-to-use mail transfer agent (MTA).  OpenSMTPD
+@strong{listens} for incoming mail and @strong{matches} the mail to
+@strong{actions}. The following records represent those stages:
 
-@lisp
-(service opensmtpd-service-type
-         (opensmtpd-configuration
-           (config-file (local-file "./my-smtpd.conf"))))
+@multitable {aaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @strong{listens}
+@tab @code{<opensmtpd-interface>}
+@item
+@tab @code{<opensmtpd-socket>}
+@item
+@tab
+@item @strong{matches}
+@tab @code{<opensmtpd-match>}
+@item
+@tab
+@item @strong{actions}
+@tab @code{<opensmtpd-local-delivery>}
+@item
+@tab @code{<opensmtpd-relay>}
+@end multitable
+
+Additionally, each @code{<opensmtpd-interface>} and
+@code{<opensmtpd-socket>} may use a list of @code{<opensmtpd-filter>},
+and/or @code{<opensmtpd-filter-phase>} records to filter
+email/spam. Also numerous records' fieldnames use
+@code{<opensmtpd-table>} records to hold lists or key value pairs of
+data.  Be sure to read the @code{<opensmtpd-table>} section to learn the
+differance between a @code{mapping table} and a @code{list table}.
+
+Finally, both @code{<opensmtpd-match>} and
+@code{<opensmtpd-filter-phase>} use @code{<opensmtpd-option>} to
+configure various options.
+
+A simple example opensmtpd configuration is below:
+
+@lisp
+(let ((smtp.gnu.org (opensmtpd-pki
+                        (domain "smtp.gnu.org")
+                        (cert "file.cert")
+                        (key "file.key"))))
+  (service opensmtpd-service-type
+           (opensmtpd-configuration
+            (interfaces (list
+                         (opensmtpd-interface
+                          (pki smtp.gnu.org))
+                         (opensmtpd-interface
+                          (pki smtp.gnu.org)
+                          (secure-connection "smtps"))))
+            (matches (list
+                      (opensmtpd-match
+                       (action
+                        (opensmtpd-local-delivery
+                         (name "local-delivery"))))
+                      (opensmtpd-match
+                       (action
+                        (opensmtpd-relay
+                         (name "relay")))))))))
 @end lisp
 @end deffn
 
@@ -25425,7 +25475,7 @@ Data type representing the configuration of opensmtpd.
 
 @table @asis
 @item @code{package} (default: @var{opensmtpd})
-Package object of the OpenSMTPD SMTP server.
+Package object of the OpenSMTPD server.
 
 @item @code{config-file} (default: @code{%default-opensmtpd-config-file})
 File-like object of the OpenSMTPD configuration file to use.  By default
@@ -25433,14 +25483,1013 @@ it listens on the loopback network interface, and allows for mail from
 users and daemons on the local machine, as well as permitting email to
 remote servers.  Run @command{man smtpd.conf} for more information.
 
+@item @code{bounce} (default: @code{(list "4h")})
+@code{bounce} is a list of strings, which send warning messages to the
+envelope sender when temporary delivery failures cause a message to
+remain in the queue for longer than a specified delay. Each delay option
+is a string parameter beginning with a positive decimal integer and a
+unit, which can be 's', 'm', 'h', or 'd'. At most four delay parameters
+can be specified.
+
+@item @code{interfaces} default:
+@lisp
+(list
+  (opensmtpd-interface
+    (interface "lo")
+    (port 25)))
+@end lisp
+@code{interfaces} is a list of @code{<opensmtpd-interface>} records.
+This list details what interfaces and ports OpenSMTPD listens on as well as
+other options.
+
+@item @code{socket} (default: @code{(opensmtpd-socket)})
+Listens for incoming connections on the Unix domain socket.
+
+@item @code{includes} (default: @code{#f})
+@code{includes} is a list of string filenames. Each filename's contents is
+additional configuration that is inserted into the top of the configuration
+file.  Run @code{man smtpd.conf} for more information.
+
+@item @code{matches} default:
+@lisp
+(list (opensmtpd-match
+       (action (opensmtpd-local-delivery
+                (name "local")
+                (method "mbox")
+                (options
+                 (list
+                  (opensmtpd-option
+                   (option "for local")))))))
+      (opensmtpd-match
+       (action (opensmtpd-relay
+                (name "outbound")))
+       (options
+        (list
+         (opensmtpd-option
+          (option "from local"))
+         (opensmtpd-option
+          (option "for any"))))))
+@end lisp
+@code{matches} is a list of @code{<opensmtpd-match>} records, which
+matches incoming mail and sends it to a correspending action. The match
+records are evaluated sequentially, with the first match winning.
+Therefore @emph{the order that you arrange your matches is important}.
+It's a good idea to put specific matches first and an all emcompassing
+match (like @code{(option "for any")}) @strong{last}. If an incoming
+mail does not match any match records, then it is rejected.
+
+@item @code{mta-max-deferred} (default: @code{100})
+When delivery to a given host is suspended due to temporary failures, cache
+at most number envelopes for that host such that they can be delivered as
+soon as another delivery succeeds to that host. The default is 100.
+
+@item @code{queue} (default: @code{#f})
+@code{queue} expects an @code{<opensmtpd-queue>} record. With it, one may
+compress and encrypt queue-ed emails as well as set the default expiration
+time for temporarily undeliverable messages.
+
+@item @code{smtp} (default: @code{#f})
+@code{smtp} expects an @code{<opensmtpd-smtp>} record, which lets one
+specifiy how large email may be along with other settings.
+
+@item @code{srs} (default: @code{#f})
+@code{srs} expects an @code{<opensmtpd-srs>} record, which lets one set
+up SRS, the Sender Rewritting Scheme.
+
 @item @code{setgid-commands?} (default: @code{#t})
 Make the following commands setgid to @code{smtpq} so they can be
 executed: @command{smtpctl}, @command{sendmail}, @command{send-mail},
 @command{makemap}, @command{mailq}, and @command{newaliases}.
 @xref{Setuid Programs}, for more information on setgid programs.
+
 @end table
 @end deftp
 
+@itemize
+@item Data Type: opensmtpd-interface
+Data type representing the configuration of an
+@code{<opensmtpd-interface>}. It listens on the fieldname
+@code{interface} for incoming connections, using the same syntax as
+@code{ifconfig}. The interface parameter may also be an string interface
+group, an string IP address, or a string domain name. Listening can
+optionally be restricted to a specific address via the fieldname
+@code{family}, which can be either @code{"inet4"} or @code{"inet6"}.
+
+@itemize
+@item @code{interface} (default: @code{"lo"})
+
+The string interface to listen for incoming connections.  This string
+may be an interface group, an IP address, or a domain name. These
+interfaces can usually be found by the command @code{ip link}.
+
+@item @code{family} (default: @code{#f})
+
+Only listen on a specific address family.  Valid strings are
+@code{"inet4"} or @code{"inet6"}, which will only listen on IPv4 or IPv6
+respectfully.  If @code{(family #f)}, then opensmtpd will listen on both
+IPv4 and IPv6.
+
+@item @code{auth} (default: @code{#f})
+Support SMTPAUTH: clients may only start SMTP transactions after
+successful authentication. If @code{auth} is @code{#t}, then users are
+authenticated against their own normal login credentials. Alternatively
+@code{auth} may be a @code{mapping table} that maps usernames to
+encrypted passwords.  The password can be encrypted via the
+@code{smtpctl} @code{encrypt} subcommand.
+
+@item @code{auth-optional} (default: @code{#f})
+Support SMTPAUTH optionally: clients need not authenticate, but may do
+so.  This allows the @code{<opensmtpd-interface>} to both accept
+incoming mail from untrusted senders and permit outgoing mail from
+authenticated users. It can be used in situations where it is not
+possible to listen on a separate port (usually the submission port, 587)
+for users to authenticate.  This option also accepts a @code{mapping
+table} that maps usernames to encrypted passwords.
+
+@item @code{filters} (default: @code{#f})
+A list of one or many @code{<opensmtpd-filter>} or
+@code{<opensmtpd-filter-phase>} records. The filters are applied
+sequentially. These records listen and filter on connections handled by this
+listener.
+
+@item @code{hostname} (default: @code{#f})
+Change the default server name in the greeting banner instead of the
+default one.
+
+@item @code{hostnames} (default: @code{#f})
+Override the server name for specific addresses. Use a @code{mapping
+table} that maps string IP addresses to string hostnames. If the address
+on which the connection arrives appears in the mapping, the associated
+hostname is used.
+
+@item @code{mask-src} (default: @code{#f})
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{disable-dsn} (default: @code{#f})
+When @code{#t}, then disable the DSN (Delivery Status Notification) extension.
+
+@item @code{pki} (default: @code{#f})
+For secure connections, use an @code{<opensmtpd-pki>} record to prove a
+mail server's identity.
+
+@item @code{port} (default: @code{25})
+Listen on the integer port instead of the default port of 25.
+
+@item @code{proxy-v2} (default: @code{#f})
+If @code{#t}, then support the PROXYv2 protocol, rewriting appropriately source
+address received from proxy.
+
+@item @code{received-auth} (default: @code{#f})
+If @code{#t}, then in “Received” headers, report whether the session was
+authenticated and by which local user.
+
+@item @code{senders} (default: @code{#f})
+Look up the authenticated user in the supplied @code{mapping table} to
+find the email addresses that user is allowed to submit mail as.
+
+@item @code{masquerade} (default: @code{#f})
+@code{masquerade}, is used in conjunction with @code{senders}.  If
+@code{#t}, then the From header is rewritten to match the sender
+provided in the SMTP session.  If @code{senders} is @code{#false}, then
+@code{masquerade} cannot be @code{#t}.
+
+@item @code{secure-connection} (default: @code{#f})
+This is a string of one of these options:
+
+@multitable {aaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"smtps"}
+@tab Support SMTPS, by default on port 465.
+@item @code{"tls"}
+@tab Support STARTTLS, by default on port 25.
+@item @code{"tls-require"}
+@tab Like @code{"tls"}, but force clients to
+@item
+@tab establish a secure connection before being
+@item
+@tab allowed to start an SMTP transaction.
+@item @code{"tls-require-verify"}
+@tab Like @code{"tls-require"}, but clients must
+@item
+@tab also provide a valid certificate
+@item
+@tab to establish an SMTP session.
+@end multitable
+
+@item @code{tag} (default: @code{#f})
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-socket
+Data type representing the configuration of an
+@code{<opensmtpd-socket>}. Listen for incoming SMTP connections on the
+Unix domain socket @samp{/var/run/smtpd.sock}. This is done by default,
+even if the record is absent.
+
+@itemize
+@item @code{filters} (default: @code{#f})
+A list of one or many @code{<opensmtpd-filter>} or
+@code{<opensmtpd-filter-phase>} records. These filter incoming
+connections handled by this listener.
+
+@item @code{mask-src} (default: @code{#f})
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{tag} (default: @code{#f})
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-match
+@cindex opensmtpd-match
+This data type represents the configuration of an
+@code{<opensmtpd-match>} record.
+
+If at least one mail envelope matches the options of one match record,
+receive the incoming message, put a copy into each matching envelope,
+and atomically save the envelopes to the mail spool for later processing
+by the respective @code{<opensmtpd-action>} found in fieldname
+@code{action}.  Here is an example @code{opensmtpd-match}
+record.
+
+@lisp
+(opensmtpd-match
+ (action (opensmtpd-local-delivery
+          (name "receive")
+          (method (opensmtpd-maildir
+                   (pathname "/home/%@{rcpt.user@}/Maildir")
+                   (junk #t)))
+          (virtual (opensmtpd-table
+                    (name "virt")
+                    (data '(("carmen" . "carmen@@gnu.org")))))))
+ (options (list (opensmtpd-option
+                 (option "from any"))
+                (opensmtpd-option
+                 (option "for domain")
+                 (data (opensmtpd-table
+                        (name "domain-table")
+                        (data (list "gnu.org" "fsf.org"))))))))
+@end lisp
+
+@itemize
+@item @code{action} (default: @code{#f})
+
+If mail matches this match configuration, then do this action. Valid values
+include @code{<opensmtpd-local-delivery>} or
+@code{<opensmtpd-relay>}.
+
+@item @code{options} (default: @code{#f})
+The fieldname @code{option} is a list of unique
+@code{<opensmtpd-option>} records.
+
+There are some mutually exclusive options: there can be only one ``for''
+and only one ``from'' option.
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@headitem for
+@tab from
+@item only use one of the following:
+@tab only use one of the following:
+@item @code{"for any"}
+@tab @code{"from any"}
+@item @code{"for local"}
+@tab @code{"from auth"}
+@item @code{"for domain"}
+@tab @code{"from local"}
+@item @code{"for rcpt-to"}
+@tab @code{"from mail-from"}
+@item
+@tab @code{"from socket"}
+@item
+@tab @code{"from src"}
+@end multitable
+
+Additionally, some options require additional data via
+@code{<opensmtpd-option>}'s fieldname @code{data}.  The following list
+will explain the below syntax.
+
+@itemize
+@item @code{"for any"}
+This option only requires fieldname @code{option} to have the string
+@code{"for any"}:
+
+@lisp
+      (opensmtpd-option
+       (option "for any"))
+@end lisp
+
+@item @code{"tag"} _tag_
+This option only requires fieldname @code{option} to have the string
+@code{"tag"} with a string in fieldname @code{data}:
+
+@lisp
+      (opensmtpd-option
+       (option "tag")
+       (data "this-tag"))
+@end lisp
+
+@item @code{"for rcpt"} _domain_ | <list table>
+This option requires fieldname @code{data} to have a string domain or
+@code{list table}:
+
+@lisp
+      (opensmtpd-option
+       (option "for rcpt")
+       (data "gnu.org"))
+@end lisp
+
+OR
+
+@lisp
+      (opensmtpd-option
+       (option "for rcpt")
+       (data (list "gnu.org" "fsf.org")))
+@end lisp
+@end itemize
+
+The following matching options are supported and can all be negated (via not
+#t). The options that support a table (anything surrounded with '<' and '>'
+eg: <table>), also support specifying regex via (regex #t).
+
+@itemize
+@item @code{"for any"}
+Specify that session may address any destination.
+
+@item @code{"for local"}
+Specify that session may address any local domain.  This is the default,
+and may be omitted.
+
+@item @code{"for domain"} _domain_ | <domain>
+Specify that session may address the string _domain_ or
+@code{list table} <domain>.
+
+@item @code{"for rcpt-to"} _recipient_ | <recipient>
+Specify that session may address the string _recipient_ or list table
+<recipient>.
+
+@item @code{"from any"}
+Specify that session may originate from any source.
+
+@item @code{"from auth"}
+Specify that session may originate from any authenticated user, no matter
+the source IP address.
+
+@item @code{"from auth"} _user_ | <user>
+Specify that the session may originate from authenticated _user_ or
+@code{list table} <user>, no matter the source IP address.
+
+@item @code{"from local"}
+Specify that session may only originate from a local IP address, or from
+the local enqueuer.  This is the default, and may be omitted.
+
+@item @code{"from mail-from"} _sender_ | <sender>
+Specify that session may originate from _sender_ or @code{list table}
+<sender>, no matter the source IP address.
+
+@item @code{"from rdns"}
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS@.
+
+@item @samp{"from rdns"} _hostname_ | <hostname>
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS matching string _hostname_ or @code{list table}
+<hostname>.
+
+@item @samp{"from socket"}
+Specify that session may only originate from the local enqueuer.
+
+@item @code{"from src"} _address_ | <address>
+Specify that session may only originate from string _address_ or
+@code{list table} <address> which can be a specific address or a subnet
+expressed in CIDR-notation.
+
+@item @code{"auth"}
+Matches transactions which have been authenticated.
+
+@item @code{"auth"} _username_ | <username>
+Matches transactions which have been authenticated for string _user_ or
+@code{list table} <username>.
+
+@item @code{"helo"} _helo-name_ | <helo-name>
+Specify that session's HELO / EHLO should match the string _helo-name_
+or @code{list table} <helo-name>.
+
+@item @code{"mail-from"} _sender_ | <sender>
+Specify that transactions's MAIL FROM should match the string _sender_
+or @code{list table} <sender>.
+
+@item @code{"rcpt-to"} _recipient_ | <recipient>
+Specify that transaction's RCPT TO should match the string _recipient_
+or @code{list table} <recipient>.
+
+@item @code{"tag"} _tag_
+Matches transactions tagged with the given tag.
+
+@item @code{"tls"}
+Specify that transaction should take place in a TLS channel.
+@end itemize
+
+@end itemize
+
+@item Data Type: opensmtpd-local-delivery
+This data type represents the configuration of an
+@code{<opensmtpd-local-delivery>} record.
+
+@itemize
+@item @code{name} (default: @code{#f})
+@code{name} is the string name of the relay action.
+
+@item @code{method} (default: @code{"mbox"})
+The email delivery option.  Valid options are:
+
+@itemize
+@item @code{"mbox"}
+Deliver the message to the user's mbox with mail.local(8).
+
+@item @code{"expand-only"}
+Only accept the message if a delivery method was specified in an aliases
+or .forward file.
+
+@item @code{"forward-only"}
+Only accept the message if the recipient results in a remote address after
+the processing of aliases or forward file.
+
+@item @code{<opensmtpd-lmtp>}
+Deliver the message to an LMTP server at @code{<opensmtpd-lmtp>}'s
+fieldname @code{destination}. The location may be expressed as string
+host:port or as a UNIX socket. Optionally, @code{<opensmtpd-lmtp>}'s
+fieldname @code{rcpt-to} might be specified to use the recipient email
+address (after expansion) instead of the local user in the LMTP session
+as RCPT TO.
+
+@item @code{<opensmtpd-maildir>}
+Deliver the message to the maildir in
+@code{<opensmtpd-maildir>}'s fieldname @code{pathname} if specified,
+or by default to @code{"~/Maildir"}.
+
+The pathname may contain format specifiers that are expanded before use
+(see the below section about Format Specifiers).
+
+If @code{<opensmtpd-maildir>}'s record fieldname @code{junk} is @code{#t},
+then message will be moved to the ‘Junk’ folder if it contains a positive
+‘X-Spam’ header. This folder will be created under fieldname @code{pathname} if
+it does not yet exist.
+
+@item @code{<opensmtpd-mda>}
+Delegate the delivery to the @code{<opensmtpd-mda>}'s fieldname
+@code{command} (type string) that receives the message on its standard input.
+
+The @code{command} may contain format specifiers that are expanded before use
+(see Format Specifiers).
+@end itemize
+
+@item @code{alias} (default: @code{#f})
+Use the @code{mapping table} for aliases expansion.
+
+@item @code{ttl} (default: @code{#f})
+@code{ttl} is a string specify how long a message may remain in the queue.  It's
+format is @code{n@{s|m|h|d@}}.  eg: @code{"4m"} is four minutes.
+
+@item @code{user} (default: @code{#f} )
+@code{user} is the string username for performing the delivery, to be looked up
+with getpwnam(3).
+
+This is used for virtual hosting where a single username is in charge of
+handling delivery for all virtual users.
+
+This option is not usable with the mbox delivery method.
+
+@item @code{userbase} (default: @code{#f})
+@code{userbase} is an @code{<opensmtpd-table>} record for mapping user
+lookups instead of the getpwnam(3) function.
+
+The fieldnames @code{user} and @code{userbase} are mutually exclusive.
+
+@item @code{virtual} (default: @code{#f})
+@code{virtual} is an @code{<opensmtpd-table>} record is used for virtual
+expansion.
+@end itemize
+
+@item Data Type: opensmtpd-relay
+This data type represents the configuration of an
+@code{<opensmtpd-relay>} record.
+
+@itemize
+@item @code{name} (default: @code{#f})
+@code{name} is the string name of the relay action.
+
+@item @code{backup} (default: @code{#f})
+When @code{#t}, operate as a backup mail exchanger delivering messages to any
+mail exchanger with higher priority.
+
+@item @code{backup-mx} (default: @code{#f})
+Operate as a backup mail exchanger delivering messages to any mail exchanger
+with higher priority than mail exchanger identified as string name.
+
+@item @code{helo} (default: @code{#f})
+Advertise string heloname as the hostname to other mail exchangers during
+the HELO phase.
+
+@item @code{helo-src} (default: @code{#f} )
+ Use the mapping @code{<opensmtpd-table>} to look up a hostname
+matching the source address, to advertise during the HELO phase.
+
+@item @code{domain} (default: @code{#f})
+Do not perform MX lookups but look up destination domain in an
+@code{<opensmtpd-table>} and use matching relay url as relay host.
+
+@item @code{host} (default: @code{#f})
+Do not perform MX lookups but relay messages to the relay host described by
+the string relay-url. The format for relay-url is
+@samp{[proto://[label@@]]host[:port]}. The following protocols are available:
+
+@multitable {aaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{smtp}
+@tab Normal SMTP session with opportunistic STARTTLS (the default).
+@item @code{smtp+tls}
+@tab Normal SMTP session with mandatory STARTTLS@.
+@item @code{smtp+notls}
+@tab Plain text SMTP session without TLS@.
+@item @code{lmtp}
+@tab LMTP session.  port is required.
+@item @code{smtps}
+@tab SMTP session with forced TLS on connection, default port is
+@item
+@tab 465.
+@end multitable
+
+Unless noted, port defaults to 25.
+
+The label corresponds to an entry in a credentials table, as documented in
+@code{man table}. It is used with the @code{"smtp+tls"} and @code{"smtps"} protocols for
+authentication. Server certificates for those protocols are verified by
+default.
+
+@item @code{pki} (default: @code{#f})
+For secure connections, use the certificate associated with
+@code{<opensmtpd-pki>} (declared in a pki directive) to prove the
+client's identity to the remote mail server.
+
+@item @code{srs} (default: @code{#f})
+If @code{#t}, then when relaying a mail resulting from a forward, use the Sender
+Rewriting Scheme to rewrite sender address.
+
+@item @code{tls} (default: @code{#f}) boolean or string ``no-verify''
+When @code{#t}, Require TLS to be used when relaying, using mandatory STARTTLS by
+default. When used with a smarthost, the protocol must not be
+@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not require a valid
+certificate.
+
+@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table>}
+Use the alist @code{<opensmtpd-table>} for connecting to relay-url
+using credentials. This option is usable only with fieldname @code{host} option.
+
+@item @code{mail-from} (default: @code{#f}) string
+Use the string mailaddress as MAIL FROM address within the SMTP transaction.
+
+@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-table>}
+Use the string or @code{<opensmtpd-table>} sourceaddr for the
+source IP address, which is useful on machines with multiple interfaces. If
+the list contains more than one address, all of them are used in such a way
+that traffic is routed as efficiently as possible.
+@end itemize
+
+@item Data Type: opensmtpd-filter
+This data type represents the configuration of an
+@code{<opensmtpd-filter>}. This is the filter record one should use
+if they want to use an external package to filter email eg: rspamd or
+spamassassin.
+
+@itemize
+@item @code{name} (default: @code{#f})
+The string name of the filter.
+
+@item @code{proc} (default: @code{#f})
+The string command or process name.  If @code{proc-exec} is @code{#t}, @code{proc} is
+treated as a command to execute.  Otherwise, it is a process name.
+
+@item @code{proc-exec} (default: @code{#f})
+If @code{#t}, then execute the command in @code{proc}.
+@end itemize
+
+@item Data Type: opensmtpd-filter-phase
+This data type represents the configuration of an
+@code{<opensmtpd-filter-phase>}.
+
+In a regular workflow, @code{smtpd(8)} may accept or reject a message
+based only on the content of envelopes. Its decisions are about the
+handling of the message, not about the handling of an active session.
+
+Filtering extends the decision making process by allowing
+@code{smtpd(8)} to stop at each phase of an SMTP session, check that
+options are met, then decide if a session is allowed to move forward.
+
+With filtering via an @code{<opensmtpd-filter-phase>} record, a
+session may be interrupted at any phase before an envelope is complete. A
+message may also be rejected after being submitted, regardless of whether the
+envelope was accepted or not.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+The string name of the filter phase.
+
+@item @code{phase-name} (default: @code{#f})
+The string name of the phase. Valid values are:
+
+@multitable {aaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"connect"}
+@tab upon connection, before a banner is displayed
+@item @code{"helo"}
+@tab after HELO command is submitted
+@item @code{"ehlo"}
+@tab after EHLO command is submitted
+@item @code{"mail-from"}
+@tab after MAIL FROM command is submitted
+@item @code{"rcpt-to"}
+@tab after RCPT TO command is submitted
+@item @code{"data"}
+@tab after DATA command is submitted
+@item @code{"commit"}
+@tab after message is fully is submitted
+@end multitable
+
+@item @code{options} (default @code{#f})
+A list of unique @code{<opensmtpd-option>} records.
+
+At each phase, various options, specified by a list of
+@code{<opensmtpd-option>}, may be checked. The
+@code{<opensmtpd-option>}'s fieldname @code{option} values of:
+@code{"fcrdns"}, @code{"rdns"}, and @code{"src"} data are available in
+all phases, but other data must have been already submitted before they
+are available. Options with a @code{<table>} next to them require the
+@code{<opensmtpd-option>}'s fieldname @code{data} to be an
+@code{<opensmtpd-table>}. There are the available options:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"fcrdns"}
+@tab forward-confirmed reverse DNS is valid
+@item @code{"rdns"}
+@tab session has a reverse DNS
+@item @code{"rdns"} <table>
+@tab session has a reverse DNS in table
+@item @code{"src"} <table>
+@tab source address is in table
+@item @code{"helo"} <table>
+@tab helo name is in table
+@item @code{"auth"}
+@tab session is authenticated
+@item @code{"auth"} <table>
+@tab session username is in table
+@item @code{"mail-from"} <table>
+@tab sender address is in table
+@item @code{"rcpt-to"} <table>
+@tab recipient address is in table
+@end multitable
+
+These conditions may all be negated by setting
+@code{(opensmtpd-option (bool #f))}.
+
+Any conditions that require a table may indicate that tables include regexs
+setting @code{(opensmtpd-option (regex #t))}.
+
+@item @code{decision}
+A string decision to be taken. Some decisions require an @code{message}
+or @code{value}.  The value and message may be put in the
+@code{<opensmtpd-option>}'s fieldname @code{data}.  Valid strings are:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"bypass"}
+@tab the session or transaction bypasses filters
+@item @code{"disconnect"} message
+@tab the session is disconnected with message
+@item @code{"junk"}
+@tab the session or transaction is junked,
+@item
+@tab  i.e., an ‘X-Spam: yes’ header is added to
+@item
+@tab any messages
+@item @code{"reject"} message
+@tab the command is rejected with message
+@item @code{"rewrite"} value
+@tab the command parameter is rewritten with value
+@end multitable
+
+Decisions that involve a message require that the message be RFC valid,
+meaning that they should either start with a 4xx or 5xx status code.
+Descisions can be taken at any phase, though junking can only happen before
+a message is committed.
+
+@item @code{message} (default @code{#f})
+A string message beginning with a 4xx or 5xx status code.
+
+@item @code{value} (default: @code{#f})
+A number value.  @code{value} and @code{message} are mutually exclusive.
+@end itemize
+
+@item Data Type: opensmtpd-option
+This data type represents the configuration of an
+@code{<opensmtpd-option>}, which is used by
+@code{<opensmtpd-filter-phase>} and @code{<opensmtpd-match>}
+to match various options for email.
+
+@itemize
+@item @code{option} (default @code{#f}) string
+
+A string option to be taken. Some options require the fieldname
+@code{data} to have a string or an @code{<opensmtpd-table>}. When the
+option record is used inside of an @code{<opensmtpd-filter-phase>}, then
+valid strings for fieldname @code{option} are:
+
+@itemize
+@item @code {"fcrdns"}
+@item @code {"rdns"}
+@item @code {"src"}
+@item @code {"helo"}
+@item @code {"auth"}
+@item @code {"mail-from"}
+@item @code {"rcpt-to"}
+@end itemize
+
+When @code{<opensmtpd-option>} is used inside of an
+@code{<opensmtpd-match>}, then valid strings for fieldname @code{option}
+are:
+
+@itemize
+@item @code {"for"}
+@item @code {"for any"}
+@item @code {"for local"}
+@item @code {"for domain"}
+@item @code {"for rcpt-to"}
+@item @code {"from any"}
+@item @code {"from auth"}
+@item @code {"from local"}
+@item @code {"from mail-from"}
+@item @code {"from rdns"}
+@item @code {"from socket"}
+@item @code {"from src"}
+@item @code {"auth"}
+@item @code {"helo"}
+@item @code {"mail-from"}
+@item @code {"rcpt-to"}
+@item @code {"tag"}
+@item @code {"tls"}
+@end itemize
+
+@item @code{data} (default @code{#f}) string | @code{<opensmtpd-table>}
+Some options require a string or @code{<opensmtpd-table>} to be
+present. One would specify that table here.
+
+@item @code{regex} (default: @code{#f}) boolean
+Any options using a table may indicate that tables hold regular
+expressions by setting this option to @code{#t}.
+
+@item @code{bool} (default: @code{#t}) boolean
+When @code{(bool #f)}, this option record is negated.
+@end itemize
+
+@item Data Type: opensmtpd-table
+This data type represents the configuration of an
+@code{<opensmtpd-table>}.
+
+@itemize
+@item @code{name} (default @code{#f})
+@code{name} is the name of the @code{<opensmtpd-table>} record.
+
+@item @code{data} (default: @code{#f}) string | list | alist | nested-list
+@code{data} expects a string, a list of strings, an alist of strings, or
+a nested list of strings.
+eg:
+
+@itemize
+
+@item string
+@lisp
+(data "dev@@gnu.org")
+@end lisp
+
+A table of this type is called a @code{string table}.
+
+@item list
+@lisp
+(data (list ("gnu.org" "fsf.org")))
+@end lisp
+
+A table of this type is called a @code{list table}.
+
+@item alist
+@lisp
+(data '(("james" . "$encryptedPassword")
+        ("jennifer" . "$encryptedPassword2)))
+@end lisp
+
+A table of this type is called a @code{mapping table}.
+
+@item nested-list
+@lisp
+(data '(("user1" "root@@gnu.org" "admin@@gnu.org")
+        ("user2" "james@@guix.gnu.org" "sarah@@fsf.org")))
+@end lisp
+
+A table of this type is also called a @code{mapping table}.
+
+@end itemize
+@end itemize
+
+@item Data Type: opensmtpd-pki
+This data type represents the configuration of an
+@code{<opensmtpd-pki>}.
+
+@itemize
+@item @code{domain} (default @code{#f})
+@code{domain} is the string name of the @code{<opensmtpd-pki>} record.
+
+@item @code{cert} (default: @code{#f})
+@code{cert} (default: @code{#f})
+
+@code{cert} is the string certificate filename to use for this pki.
+
+@item @code{key} (default: @code{#f})
+@code{key} is the string certificate falename to use for this pki.
+
+@item @code{dhe} (default: @code{"none"})
+Specify the DHE string parameter to use for DHE cipher suites with host
+pkiname. Valid parameter values are @code{"none"}, @code{"legacy"}, or
+@code{"auto"}. For @code{"legacy"}, a fixed key length of 1024 bits is
+used, whereas for @code{"auto"}, the key length is determined
+automatically. The default is @code{"none"}, which disables DHE cipher
+suites.
+@end itemize
+
+@item Data Type: opensmtpd-maildir
+@itemize
+@item @code{pathname} (default: @code{"~/Maildir"})
+Deliver the message to the maildir if pathname if specified, or by default
+to @code{"~/Maildir"}.
+
+The pathname may contain format specifiers that are expanded before use
+(see FORMAT SPECIFIERS).
+
+@item @code{junk} (default: @code{#f})
+If the junk argument is @code{#t}, then the message will be moved to the @samp{‘Junk’}
+folder if it contains a positive @samp{‘X-Spam’} header. This folder will be
+created under pathname if it does not yet exist.
+@end itemize
+
+@item Data Type: opensmtpd-mda
+This record lets you delegate the delivery to a command that receives
+the message on its standard input.
+
+@itemize
+@item @code{name}
+The string name for this MDA command.
+
+@item @code{command}
+The command to that delivers the mail.
+
+The command may contain format specifiers that are expanded before use (see
+FORMAT SPECIFIERS).
+@end itemize
+
+@item Data Type: opensmtpd-queue
+@itemize
+@item @code{compression} (default @code{#f})
+Store queue files in a compressed format. This may be useful to save disk
+space.
+
+@item @code{encryption} (default @code{#f})
+Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If no key is specified, it is
+read with getpass(3). If the string stdin or a single dash (‘-’) is given
+instead of a key, the key is read from the standard input.
+
+@item @code{ttl-delay} (default @code{#f})
+Set the default expiration time for temporarily undeliverable messages,
+given as a positive decimal integer followed by a unit s, m, h, or d. The
+default is four days (@code{"4d"}).
+@end itemize
+
+@item Data Type: opensmtpd-smtp
+Data type representing an @code{<opensmtpd-smtp>} record.
+
+@itemize
+@item @code{ciphers} (default: @code{#f})
+Set the control string for SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default is
+         ``HIGH:!aNULL:!MD5''.
+
+@item @code{limit-max-mails} (default: @code{100})
+Limit the number of messages to count for each sessio
+
+@item @code{limit-max-rcpt} (default: @code{1000})
+Limit the number of recipients to count for each transaction.
+
+@item @code{max-message-size} (default: @code{35M})
+Reject messages larger than size, given as a positive number of bytes or as
+a string to be parsed with scan@math{_scaled}(3).
+
+@item @code{sub-addr-delim character} (default: @code{+})
+When resolving the local part of a local email address, ignore the ASCII
+character and all characters following it. This is helpful for email
+filters. @samp{"admin+bills@@gnu.org"} is the same email address as
+@samp{"admin@@gnu.org"}. BUT an email filter can filter emails addressed to first
+email address into a 'Bills' email folder.
+@end itemize
+
+@item Data Type: opensmtpd-srs
+Use this record to set up the Sender Rewriting Scheme (SRS).
+
+@itemize
+@item @code{key} (default: @code{#f})
+Set the secret key to use for SRS, the Sender Rewriting Scheme.
+
+@item @code{backup-key} (default: @code{#f})
+Set a backup secret key to use as a fallback for SRS@. This can be used to
+implement SRS key rotation.
+
+@item @code{ttl-delay} (default: @code{"4d"})
+Set the time-to-live delay for SRS envelopes. After this delay, a bounce
+reply to the SRS address will be discarded to limit risks of forged
+addresses.
+@end itemize
+
+@item Format Specifiers
+Some configuration records support expansion of their parameters at
+runtime. Such records (for example
+@code{<opensmtpd-maildir>}, @code{<opensmtpd-mda>}) may use
+format specifiers which are expanded before delivery or relaying. The
+following formats are currently supported:
+
+@multitable {aaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{sender@}}
+@tab sender email address, may be empty string
+@item @samp{%@{sender.user@}}
+@tab user part of the sender email address, may be empty
+@item @samp{%@{sender.domain@}}
+@tab domain part of the sender email address, may be empty
+@item @samp{%@{rcpt@}}
+@tab recipient email address
+@item @samp{%@{rcpt.user@}}
+@tab user part of the recipient email address
+@item @samp{%@{rcpt.domain@}}
+@tab domain part of the recipient email address
+@item @samp{%@{dest@}}
+@tab recipient email address after expansion
+@item @samp{%@{dest.user@}}
+@tab user part after expansion
+@item @samp{%@{dest.domain@}}
+@tab domain part after expansion
+@item @samp{%@{user.username@}}
+@tab local user
+@item @samp{%@{user.directory@}}
+@tab home directory of the local user
+@item @samp{%@{mbox.from@}}
+@tab name used in mbox From separator lines
+@item @samp{%@{mda@}}
+@tab mda command, only available for mda wrappers
+@end multitable
+
+Expansion formats also support partial expansion using the optional bracket notations
+with substring offset.  For example, with recipient domain @samp{“example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt.domain[0]@}}
+@tab expands to “e”
+@item @samp{%@{rcpt.domain[1]@}}
+@tab expands to “x”
+@item @samp{%@{rcpt.domain[8:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[-3:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[0:6]@}}
+@tab expands to “example”
+@item @samp{%@{rcpt.domain[0:-4]@}}
+@tab expands to “example”
+@end multitable
+
+In addition, modifiers may be applied to the token.  For example, with recipient
+@samp{“User+Tag@@Example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt:lowercase@}}
+@tab expands to “user+tag@@example.org”
+@item @samp{%@{rcpt:uppercase@}}
+@tab expands to “USER+TAG@@EXAMPLE.ORG”
+@item @samp{%@{rcpt:strip@}}
+@tab expands to “User@@Example.org”
+@item @samp{%@{rcpt:lowercasestrip@}}
+@tab expands to “user@@example.org”
+@end multitable
+
+For security concerns, expanded values are sanitized and potentially dangerous
+characters are replaced with ‘:’. In situations where they are desirable, the
+“raw” modifier may be applied. For example, with recipient
+@samp{“user+t?g@@example.org”}:
+
+@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt@}}
+@tab expands to “user+t:g@@example.org”
+@item @samp{%@{rcpt:raw@}}
+@tab expands to “user+t?g@@example.org”
+@end multitable
+@end itemize
+
 @subsubheading Exim Service
 
 @cindex mail transfer agent (MTA)
diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index 43f144a42d..4175cab375 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -35,6 +35,10 @@ (define-module (gnu services mail)
   #:use-module (gnu packages admin)
   #:use-module (gnu packages dav)
   #:use-module (gnu packages tls)
+  #:use-module (guix i18n)
+  #:use-module (guix diagnostics)
+  #:use-module (guix ui)
+  #:use-module (guix utils)
   #:use-module (guix records)
   #:use-module (guix packages)
   #:use-module (guix gexp)
@@ -58,10 +62,149 @@ (define-module (gnu services mail)
             mailbox-configuration
             namespace-configuration
 
+            opensmtpd-table
+            opensmtpd-table?
+            opensmtpd-table-name
+            opensmtpd-table-data
+
+            opensmtpd-ca
+            opensmtpd-ca?
+            opensmtpd-ca-name
+            opensmtpd-ca-file
+
+            opensmtpd-pki
+            opensmtpd-pki?
+            opensmtpd-pki-domain
+            opensmtpd-pki-cert
+            opensmtpd-pki-key
+            opensmtpd-pki-dhe
+
+            opensmtpd-local-delivery
+            opensmtpd-local-delivery?
+            opensmtpd-local-delivery-method
+            opensmtpd-local-delivery-alias
+            opensmtpd-local-delivery-ttl
+            opensmtpd-local-delivery-user
+            opensmtpd-local-delivery-userbase
+            opensmtpd-local-delivery-virtual
+            opensmtpd-local-delivery-wrapper
+
+            opensmtpd-maildir
+            opensmtpd-maildir?
+            opensmtpd-maildir-pathname
+            opensmtpd-maildir-junk
+
+            opensmtpd-mda
+            opensmtpd-mda-name
+            opensmtpd-mda-command
+
+            opensmtpd-lmtp
+            opensmtpd-lmtp-destination
+            opensmtpd-lmtp-rcpt
+
+            opensmtpd-relay
+            opensmtpd-relay?
+            opensmtpd-relay-name
+            opensmtpd-relay-backup
+            opensmtpd-relay-backup-mx
+            opensmtpd-relay-helo
+            opensmtpd-relay-domain
+            opensmtpd-relay-host
+            opensmtpd-relay-pki
+            opensmtpd-relay-srs
+            opensmtpd-relay-tls
+            opensmtpd-relay-auth
+            opensmtpd-relay-mail-from
+            opensmtpd-relay-src
+
+            opensmtpd-option
+            opensmtpd-option?
+            opensmtpd-option-option
+            opensmtpd-option-bool
+            opensmtpd-option-regex
+            opensmtpd-option-data
+
+            opensmtpd-filter-phase
+            opensmtpd-filter-phase?
+            opensmtpd-filter-phase-name
+            opensmtpd-filter-phase-phase
+            opensmtpd-filter-phase-options
+            opensmtpd-filter-phase-decision
+            opensmtpd-filter-phase-message
+            opensmtpd-filter-phase-value
+
+            opensmtpd-filter
+            opensmtpd-filter?
+            opensmtpd-filter-name
+            opensmtpd-filter-proc
+
+            opensmtpd-interface
+            opensmtpd-interface?
+            opensmtpd-interface-interface
+            opensmtpd-interface-family
+            opensmtpd-interface-auth
+            opensmtpd-interface-auth-optional
+            opensmtpd-interface-filters
+            opensmtpd-interface-hostname
+            opensmtpd-interface-hostnames
+            opensmtpd-interface-mask-src
+            opensmtpd-interface-disable-dsn
+            opensmtpd-interface-pki
+            opensmtpd-interface-port
+            opensmtpd-interface-proxy-v2
+            opensmtpd-interface-received-auth
+            opensmtpd-interface-senders
+            opensmtpd-interface-masquerade
+            opensmtpd-interface-secure-connection
+            opensmtpd-interface-tag
+
+            opensmtpd-socket
+            opensmtpd-socket?
+            opensmtpd-socket-filters
+            opensmtpd-socket-mask-src
+            opensmtpd-socket-tag
+
+            opensmtpd-match
+            opensmtpd-match?
+            opensmtpd-match-action
+            opensmtpd-match-options
+
+            opensmtpd-smtp
+            opensmtpd-smtp?
+            opensmtpd-smtp-ciphers
+            opensmtpd-smtp-limit-max-mails
+            opensmtpd-smtp-limit-max-rcpt
+            opensmtpd-smtp-max-message-size
+            opensmtpd-smtp-sub-addr-delim character
+
+            opensmtpd-srs
+            opensmtpd-srs?
+            opensmtpd-srs-key
+            opensmtpd-srs-backup-key
+            opensmtpd-srs-ttl-delay
+
+            opensmtpd-queue
+            opensmtpd-queue?
+            opensmtpd-queue-compression
+            opensmtpd-queue-encryption
+            opensmtpd-queue-ttl-delay
+
             opensmtpd-configuration
             opensmtpd-configuration?
+            opensmtpd-package
+            opensmtpd-config-file
+            opensmtpd-configuration-bounce
+            opensmtpd-configuration-cas
+            opensmtpd-configuration-interfaces
+            opensmtpd-configuration-socket
+            opensmtpd-configuration-includes
+            opensmtpd-configuration-matches
+            ;;opensmtpd-configuration-mda-wrappers
+            opensmtpd-configuration-mta-max-deferred
+            opensmtpd-configuration-srs
+            opensmtpd-configuration-smtp
+            opensmtpd-configuration-queue
             opensmtpd-service-type
-            %default-opensmtpd-config-file
 
             mail-aliases-service-type
 
@@ -1641,22 +1784,2351 @@ (define (generate-dovecot-documentation)
        (listeners unix-listener-configuration fifo-listener-configuration
                   inet-listener-configuration))
       (protocol-configuration ,protocol-configuration-fields))
-  'dovecot-configuration))
+   'dovecot-configuration))
 
 \f
-;;;
 ;;; OpenSMTPD.
 ;;;
+;;; This next bit of code helps me create my own sanitizer functions.
+
+;; some fieldnames have a default value of #f, which is ok.  They cannot have
+;; a value of #t.
+;; for example opensmtpd-table-data can be #f, BUT NOT true.
+;; my/sanitize procedure tests values to see if they are of the right kind.
+;; procedure false? is needed to allow fields like 'values' to be blank,
+;; (empty), or #f BUT also have a value like a list of strings.
+(define (false? var)
+  (eq? #f var))
+
+;; TODO I have to have this procedure, or I need to change my/sanitize
+;; procedure.
+(define (my-file-exists? file)
+  (and (string? file)
+       (access? file F_OK)))
+
+;; This procedure takes in a var and a list of procedures.  It loops through
+;; list of procedures passing in var to each.
+;; if one procedure returns #t, the function returns true.  Otherwise #f.
+;; TODO for fun rewrite this using map
+;; If I rewrote it in map, then it may help with sanitizing.
+;; eg: I could then potentially easily sanitize vars with lambda procedures.
+(define (is-value-right-type? var list-of-procedures record fieldname)
+  (if (null? list-of-procedures)
+      #f
+      (if ((car list-of-procedures) var)
+          #t
+          (is-value-right-type? var (cdr list-of-procedures) record
+                                fieldname))))
+
+;; converts strings like this:
+;; "apple, ham, cherry" -> "apple, ham, or cherry"
+;; "pineapple" -> "pinneapple".
+;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
+(define (add-comma-or string)
+  (define last-comma-location (string-rindex string #\,))
+  (if last-comma-location
+      (if (string-contains string ", or" last-comma-location)
+          string
+          (string-replace string ", or" last-comma-location
+                          (+ 1 last-comma-location)))
+      string))
+
+
+(define (list-of-procedures->string procedures)
+  (define string
+    (let loop ((procedures procedures))
+      (if (null? procedures)
+          ""
+          (begin
+            (string-append
+             (cond ((eq? false? (car procedures))
+                    "#f, ")
+                   ((eq? boolean? (car procedures))
+                    "a boolean, ")
+                   ((eq? string? (car procedures))
+                    "a string, ")
+                   ((eq? integer? (car procedures))
+                    "an integer, ")
+                   ((eq? list-of-strings? (car procedures))
+                    "a list of strings, ")
+                   ((eq? assoc-list? (car procedures))
+                    "an association list of strings, ")
+                   ((eq? nested-list? (car procedures))
+                    "a nested-list of strings, ")
+                   ((eq? opensmtpd-pki? (car procedures))
+                    "an <opensmtpd-pki> record, ")
+                   ((eq? opensmtpd-table? (car procedures))
+                    "an <opensmtpd-table> record, ")
+                   ((eq? list-of-opensmtpd-match? (car procedures))
+                    "a list of unique <opensmtpd-match> records, ")
+                   ((eq? list-of-strings-or-gexps? (car procedures))
+                    "a list of strings or gexps, ")
+                   ;; TODO can I remove the next two procedures?
+                   ;; tables-data-are-a* ?  I think I can.
+                   ((eq? tables-data-are-assoc-list? (car procedures))
+                    (string-append
+                     "an <opensmtpd-table> record whose fieldname 'data' are "
+                     "an assoc-list.\nFor example: (opensmtpd-table  "
+                     "(name \"hostnames\") , "
+                     "(data '((\"124.394.23.1\" . \"gnu.org\"))))"))
+                   ((eq? tables-data-are-a-list-of-strings?
+                         (car procedures))
+                    (string-append
+                     "on <opensmtpd-table> record whose fieldname 'data' is "
+                     "a list of strings.\n"
+                     "For example: (opensmtpd-table (name \"domains\") , "
+                     "(data (list \"gnu.org\" \"guix.gnu.org\")))"))
+                   ((eq? my-file-exists? (car procedures))
+                    "a file, ")
+                   (else "has an incorrect value, "))
+             (loop (cdr procedures)))))))
+  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
+
+(define (list-of-strings-or-gexps? list)
+  (and (list? list)
+       (cond ((null? list)
+              #t)
+             ((or (string? (car list))
+                  (gexp? (car list))
+                  (local-file? (car list))
+                  (file-append? (car list))
+                  (plain-file? (car list))
+                  (computed-file? (car list))
+                  (program-file? (car list)))
+              (list-of-strings-or-gexps? (cdr list)))
+             (else #f))))
+
+(define (my/sanitize var record fieldname list-of-procedures)
+  (define try-string
+    (string-append "Try " (list-of-procedures->string list-of-procedures)))
+  (if (is-value-right-type? var list-of-procedures record fieldname)
+      var
+      (begin
+        (cond ((string? var)
+               (report-error (G_ "(~a \"~a\") is invalid.~%") fieldname var))
+              ((or (number? var) (boolean? var))
+              (report-error (G_ "(~a ~a) is invalid.~%") fieldname var) )
+              (else
+               (report-error (G_ "(~a ...) is invalid.~%Value is: ~a~%")
+                             fieldname var)))
+        (display-hint (G_ try-string))
+        (throw 'bad! var))))
+
+;;; The Opensmtpd records.
+
+;; Some example opensmtpd-tables:
+;;
+;;  (opensmtpd-table (name "root accounts")
+;;                   (data '(("joshua" . "root@dismail.de")
+;;                           ("joshua" . "postmaster@dismail.de"))))
+;;  (opensmtpd-table (name "root accounts")
+;;                   (data (list "mysite.me" "your-site.com")))
+;;  TODO: How am I supporting file: or db: tables?
+;;  Perhaps I should just automatically convert the table to a database table
+;;  if the data gets large enough.  What would be sufficently large enough?
+(define-record-type* <opensmtpd-table>
+  opensmtpd-table make-opensmtpd-table
+  opensmtpd-table?
+  (name opensmtpd-table-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table" "name"
+                                 (list string?)))))
+  ;; FIXME Support an aliasing table as described here:
+  ;; https://man.openbsd.org/table.5
+  ;; One may have to use the record file for this.  I don't think tables
+  ;; support a table like this:
+  ;; table "name" { joshua = joshua@gnucode.me,joshua@gnu-hurd.com, \
+  ;;    joshua@propernaming.org, root = root@gnucode.me }
+  ;; If values is an absolute filename, then it will use said filename to
+  ;; house the table info. filename must be an absolute filename.
+  (data opensmtpd-table-data
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-table" "data"
+                                   (list list-of-strings? assoc-list?
+                                         nested-list?))))))
+
+(define-record-type* <opensmtpd-ca>
+  opensmtpd-ca make-opensmtpd-ca
+  opensmtpd-ca?
+  (name opensmtpd-ca-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca" "name" (list string?)))))
+  (file opensmtpd-ca-file
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca" "file"
+                                 (list my-file-exists?))))))
+
+(define-record-type* <opensmtpd-pki>
+  opensmtpd-pki make-opensmtpd-pki
+  opensmtpd-pki?
+  (domain opensmtpd-pki-domain
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-pki" "domain"
+                                   (list string?)))))
+  ;; TODO/FIXME this should probably be a list of files.  The opensmtpd
+  ;; documentation says that you could have a list of files:
+  ;;
+  ;; pki pkiname cert certfile
+  ;; Associate certificate file certfile with host pkiname, and use that file
+  ;; to prove the identity of the mail server to clients.  pkiname is the
+  ;; server's name, derived from the default hostname or set using either
+  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/mailname
+  ;; or using the hostname directive.  If a fallback certificate or SNI is
+  ;; wanted, the ‘*’ wildcard may be used as pkiname.
+
+  ;; A certificate chain may be created by appending one or many certificates,
+  ;; including a Certificate Authority certificate, to certfile.  The creation
+  ;; of certificates is documented in starttls(8).
+  (cert opensmtpd-pki-cert
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-pki" "cert"
+                                 (list my-file-exists?)))))
+  (key opensmtpd-pki-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-pki" "key"
+                                (list my-file-exists?)))))
+  ; todo sanitize this. valid parameters are "none", "legacy", or "auto".
+  (dhe opensmtpd-pki-dhe
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-dhe" "dhe"
+                                (list false? string?))))))
+
+(define-record-type* <opensmtpd-lmtp>
+  opensmtpd-lmtp make-opensmtpd-lmtp
+  opensmtpd-lmtp?
+  (destination opensmtpd-lmtp-destination
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-lmtp" "destination"
+                                        (list string?)))))
+  (rcpt-to opensmtpd-lmtp-rcpt-to
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-lmtp" "rcpt-to"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-mda>
+  opensmtpd-mda make-opensmtpd-mda
+  opensmtpd-mda?
+  (name opensmtpd-mda-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-mda" "name"
+                                 (list string?)))))
+  ;; TODO should I allow this command to be a gexp?
+  (command opensmtpd-mda-command
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-mda" "command"
+                                    (list string?))))))
+
+(define-record-type* <opensmtpd-maildir>
+  opensmtpd-maildir make-opensmtpd-maildir
+  opensmtpd-maildir?
+  (pathname opensmtpd-maildir-pathname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-maildir" "pathname"
+                                     (list false? string?)))))
+  (junk opensmtpd-maildir-junk
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-maildir" "junk"
+                                 (list boolean?))))))
+
+(define-record-type* <opensmtpd-local-delivery>
+  opensmtpd-local-delivery make-opensmtpd-local-delivery
+  opensmtpd-local-delivery?
+  (name opensmtpd-local-delivery-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-local-delivery" "name"
+                                 (list string?)))))
+  (method opensmtpd-local-delivery-method
+          (default "mbox")
+          (sanitize (lambda (var)
+                      (define fieldname "method")
+                      (define options (list "mbox" "expand-only"
+                                            "forward-only"))
+                      (define options-plus-records
+                            (append options (list "(opensmtpd-lmtp ...)"
+                                                  "(opensmtpd-maildir ...)"
+                                                  "(opensmtpd-mda ...)")))
+                      (cond ((or (opensmtpd-lmtp? var)
+                                 (opensmtpd-maildir? var)
+                                 (opensmtpd-mda? var)
+                                 (member var options))
+                             var)
+                            (else
+                             (begin
+                               (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                             fieldname var)
+                               (display-hint
+                                (G_ (hint-string
+                                     var
+                                     options-plus-records
+                                     #:fieldname fieldname)))
+                               (throw 'bad! var)))))))
+  (alias opensmtpd-local-delivery-alias
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-local-delivery" "alias"
+                                  (list false?
+                                        tables-data-are-assoc-list?)))))
+  (ttl opensmtpd-local-delivery-ttl
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-local-delivery" "ttl"
+                                (list false? string?)))))
+  (user opensmtpd-local-delivery-user
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-local-delivery" "user"
+                                 (list false? string?)))))
+  (userbase opensmtpd-local-delivery-userbase
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-local-delivery" "userbase"
+                                (list false?
+                                      tables-data-are-assoc-list?)))))
+  (virtual opensmtpd-local-delivery-virtual
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-local-delivery" "virtual"
+                                    (list
+                                     false?
+                                     tables-data-are-assoc-list?)))))
+  (wrapper opensmtpd-local-delivery-wrapper
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-local-delivery" "wrapper"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-relay>
+  opensmtpd-relay make-opensmtpd-relay
+  opensmtpd-relay?
+  (name opensmtpd-relay-name
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "name"
+                                 (list string?))))
+        (default #f))
+  (backup opensmtpd-relay-backup ;; boolean
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "backup"
+                                   (list boolean?)))))
+  (backup-mx opensmtpd-relay-backup-mx ;; string mx name
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-relay" "backup-mx"
+                                      (list false? string?)))))
+  (helo opensmtpd-relay-helo
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "helo"
+                                 (list false? string?))))
+        (default #f))
+  (helo-src opensmtpd-relay-helo-src
+        (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "helo-src"
+                                   (list false? string?
+                                         tables-data-are-assoc-list?))))
+        (default #f))
+  (domain opensmtpd-relay-domain
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "domain"
+                                   (list false? opensmtpd-table?))))
+          (default #f))
+  (host opensmtpd-relay-host
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "host"
+                                 (list false? string?))))
+        (default #f))
+  (pki opensmtpd-relay-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "pki"
+                                (list false? opensmtpd-pki?)))))
+  (srs opensmtpd-relay-srs
+       (default #f)
+       (lambda (var)
+         (my/sanitize var "opensmtpd-relay" "srs"
+                      (list boolean?))))
+  (tls opensmtpd-relay-tls
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "tls"
+                                (list false? string?)))))
+  ;; the table here looks like:
+  ;; label1    user:password
+  ;; label2    user2:password2
+  ;; It is documented in the credentials table in man table
+  (auth opensmtpd-relay-auth
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "auth"
+                                 (list false?
+                                       tables-data-are-assoc-list?))))
+        (default #f))
+  (mail-from opensmtpd-relay-mail-from
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-relay" "mail-from"
+                                      (list false? string?))))
+             (default #f))
+  ;; string "127.0.0.1" or "<interface>" or "<table of IP addresses>"
+  ;; TODO should I do some sanitizing to make sure that the string?
+  ;; here is actually an IP address or a valid interface?
+  (src opensmtpd-relay-src
+       (sanitize
+        (lambda (var)
+          (my/sanitize var "opensmtpd-relay" "src"
+                       (list false? string?
+                             tables-data-are-a-list-of-strings?))))
+       (default #f)))
+
+;; this record is used by <opensmtpd-filter-phase> &
+;; <opensmtpd-match>
+(define-record-type* <opensmtpd-option>
+  opensmtpd-option make-opensmtpd-option
+  opensmtpd-option?
+  (option opensmtpd-option-option
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-option" "option"
+                                   (list string?)))))
+  (bool opensmtpd-option-bool
+       (default #t)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-option" "not"
+                                (list boolean?)))))
+  (regex opensmtpd-option-regex
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option" "regex"
+                                  (list boolean?)))))
+  (data opensmtpd-option-data
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option" "data"
+                                  (list false? string? opensmtpd-table?))))))
+
+(define-record-type* <opensmtpd-filter-phase>
+  opensmtpd-filter-phase make-opensmtpd-filter-phase
+  opensmtpd-filter-phase?
+  (name opensmtpd-filter-phase-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter-phase" "name"
+                                 (list string?)))))
+  (phase opensmtpd-filter-phase-phase ;; string
+              (default #f)
+              (sanitize
+               (lambda (var)
+                 (define options
+                   (list "connect" "helo" "ehlo" "mail-from"
+                         "rcpt-to" "data" "commit"))
+                 (define fieldname "phase")
+                 (if (and (string? var)
+                          (member var options))
+                     var
+                     (begin
+                       (report-error
+                        (G_
+                         "(opensmtpd-filter-phase ... (~a \"~a\")) is invalid.~%")
+                        fieldname var)
+                       (display-hint
+                        (G_ (hint-string var options
+                                         #:fieldname fieldname)))
+                       (throw 'bad! var))))))
+  (options opensmtpd-filter-phase-options
+           (default #f)
+           (sanitize
+            (lambda (var)
+              (cond
+               ((false? var)
+                (report-error (G_ ""))
+                (display "(opensmtpd-filter-phase (options #f)) is invalid.\n")
+                (display-hint
+                 (G_ "Try a list of (opensmtpd-option) records.\n"))
+                (throw 'bad! #f))
+               ((not (list-of-opensmtpd-option? var))
+                (report-error (G_ ""))
+                (display "(opensmtpd-filter-phase (options ...) is invalid.\n")
+                (display-hint
+                 (G_ "Try a list of (opensmtpd-option) records.\n"))
+                (throw 'bad! var))
+               (else (sanitize-options-for-filter-phase var))))))
+  (decision opensmtpd-filter-phase-decision
+            (default #f)
+            (sanitize
+             (lambda (var)
+               (define options
+                 (list "bypass" "disconnect"
+                       "reject" "rewrite" "junk"))
+               (define fieldname "decision")
+               (if (and (string? var)
+                        (member var options))
+                   var
+                   (begin
+                     (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                   fieldname var)
+                     (display-hint (G_ (hint-string var options
+                                                    #:fieldname fieldname)))
+                     (throw 'bad! var))))))
+  (message opensmtpd-filter-phase-message
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase" "message"
+                                    (list false? string?)))))
+  (value opensmtpd-filter-phase-value
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-filter-phase" "value"
+                                  (list false? number?))))))
+
+(define-record-type* <opensmtpd-filter>
+  opensmtpd-filter make-opensmtpd-filter
+  opensmtpd-filter?
+  (name opensmtpd-filter-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "name"
+                                 (list string?)))))
+  (exec opensmtpd-filter-exec
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "exec"
+                                 (list boolean?)))))
+  ;; a string like "rspamd" or the command to start it like
+  ;; "/path/to/rspamd --option=arg --2nd-option=arg2"
+  ;; OR a list of strings and/or geps.
+  (proc opensmtpd-filter-proc
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-filter" "proc"
+                                      (list string?
+                                            list-of-strings-or-gexps?))))))
+
+;; There is another type of filter that opensmtpd supports, which is a
+;; filter chain. A filter chain is a list of <opensmtpd-filter-phase>s
+;; and/or <opensmtpd-filter>s. This lets you apply several filters under
+;; one filter name.  I could have defined a record type for it, but the
+;; record would only have had two fields: name and list-of-filters.
+;; Why write that as a record?  It makes the user of this service harder.
+;; Instead, just define it as a list, and if a user wants an interface
+;; to make multiple filters, he just appends to the 'filters' fieldname.
+;;
+;; returns #t if list is a unique list of <opensmtpd-filter> or
+;; <opensmtpd-filter-phase>
+;; returns # otherwise
+(define (opensmtpd-filter-chain? %filters)
+  (and (list-of-unique-filter-or-filter-phase? %filters)
+       (< 1 (length %filters))))
+
+(define-record-type* <opensmtpd-interface>
+  opensmtpd-interface make-opensmtpd-interface
+  opensmtpd-interface?
+  ;; interface may be an IP address, interface group, or domain name
+  (interface opensmtpd-interface-interface
+             (default "lo")
+             (sanitize (lambda (var)
+                         (my/sanitize var "interface" "interface"
+                                      (list string?)))))
+  (family opensmtpd-interface-family
+          (default #f)
+          (sanitize
+           (lambda (var)
+             (define options (list "inet4" "inet6"))
+             (define fieldname "family")
+             (cond
+              ((eq? #f var) ;; var == #f
+               var)
+              ((and (string? var)
+                    (member var options))
+               var)
+              (else
+               (begin
+                 (report-error (G_ "(~a \"~a\") is invalid.~%") fieldname var)
+                 (display-hint (G_ (hint-string var options
+                                                #:fieldname fieldname)))
+                 (throw 'bad! var)))))))
+  (auth opensmtpd-interface-auth
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "auth"
+                                 (list boolean?
+                                       tables-data-are-assoc-list?)))))
+  (auth-optional opensmtpd-interface-auth-optional
+                 (default #f)
+                 (sanitize
+                  (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "auth-optional"
+                                 (list boolean?
+                                       tables-data-are-assoc-list?)))))
+  ;; TODO add a ca entry?
+  ;; string FIXME/TODO sanitize this to support a gexp.  That way way the
+  ;; includes directive can include my hacky scheme code that I use
+  ;; for opensmtpd-dkimsign.
+  (filters opensmtpd-interface-filters
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-socket-and-interfaces-filters var))))
+  (hostname opensmtpd-interface-hostname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-interface" "hostname"
+                                     (list false? string?)))))
+  (hostnames opensmtpd-interface-hostnames
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-interface" "hostnames"
+                                      (list
+                                       false?
+                                       tables-data-are-assoc-list?)))))
+  (mask-src opensmtpd-interface-mask-src
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-interface" "mask-src"
+                                     (list boolean?)))))
+  (disable-dsn opensmtpd-interface-disable-dsn
+          (default #f))
+  (pki opensmtpd-interface-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "pki"
+                                (list false? opensmtpd-pki?)))))
+  (port opensmtpd-interface-port
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "port"
+                                 (list false? integer?)))))
+  (proxy-v2 opensmtpd-interface-proxy-k2
+            (default #f))
+  (received-auth opensmtpd-interface-received-auth
+                 (default #f))
+  (senders opensmtpd-interface-senders
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-interface" "senders"
+                                    (list false?
+                                          tables-data-are-assoc-list?))))
+           (default #f))
+  (masquerade opensmtpd-interface-masquerade
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-interface" "masquerade"
+                                       (list boolean?))))
+              (default #f))
+  (secure-connection opensmtpd-interface-secure-connection
+                     (default #f)
+                     (sanitize
+                      (lambda (var)
+                        (define options
+                          (list "smtps" "tls" "tls-require"
+                                "tls-require-verify"))
+                        (define fieldname "secure-connection")
+                        (cond ((boolean? var)
+                               var)
+                              ((and (string? var)
+                                    (member var options))
+                               var)
+                              (else
+                               (begin
+                                 (report-error
+                                  (G_ "(~a \"~a\") is invalid.~%")
+                                  fieldname var)
+                                 (display-hint
+                                  (G_ (hint-string var options
+                                                   #:fieldname fieldname)))
+                                 (throw 'bad! var)))))))
+  (tag opensmtpd-interface-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+(define-record-type* <opensmtpd-socket>
+  opensmtpd-socket make-opensmtpd-socket
+  opensmtpd-socket?
+  ;; false or <opensmtpd-filter> or list of <opensmtpd-filter>
+  (filters opensmtpd-socket-filters
+           (sanitize (lambda (var)
+                       (sanitize-socket-and-interfaces-filters
+                        var
+                        #:socket-or-interface "socket")))
+          (default #f))
+  (mask-src opensmtpd-socket-mask-src
+            (default #f)
+            (my/sanitize var "opensmtpd-interface" "mask-src"
+                                (list false? boolean?)))
+  (tag opensmtpd-socket-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+
+(define-record-type* <opensmtpd-match>
+  opensmtpd-match make-opensmtpd-match
+  opensmtpd-match?
+  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
+  ;;is #t, then the match record will be a reject match record.
+  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action 'reject))
+  ;; To do this, I will also have to 'reject' mutually exclusive.
+  ;; AND an match with 'reject' can have no action defined.
+  (action opensmtpd-match-action
+          (default #f)
+          (sanitize
+           (lambda (var)
+             (define fieldname "action")
+             (if (or (opensmtpd-relay? var)
+                     (opensmtpd-local-delivery? var)
+                     (eq? (quote reject) var))
+                 var
+                 (begin
+                   (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                 fieldname var)
+                   (display-hint
+                    (G_ "Try an (opensmtpd-relay) record,
+(opensmtpd-local-delivery) record, or (quote reject)."))
+                   (throw 'bad! var))))))
+  (options opensmtpd-match-options
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-options-for-opensmtpd-match var)))))
+
+(define-record-type* <opensmtpd-smtp>
+  opensmtpd-smtp make-opensmtpd-smtp
+  opensmtpd-smtp?
+  (ciphers opensmtpd-smtp-ciphers
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-smtp" "ciphers"
+                                    (list false? string?)))))
+  (limit-max-mails opensmtpd-smtp-limit-max-mails
+                   (default #f)
+                   (sanitize (lambda (var)
+                               (my/sanitize var "opensmtpd-smtp"
+                                            "limit-max-mails"
+                                            (list false? integer?)))))
+  (limit-max-rcpt opensmtpd-smtp-limit-max-rcpt
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp"
+                                           "limit-max-rcpt"
+                                           (list false? integer?)))))
+  ;; TODO the user could enter in "zebra" which would break the config.
+  ;; I should sanitize the string to make sure it looks like "50M".
+  (max-message-size opensmtpd-smtp-max-message-size
+                    (default #f)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-smtp"
+                                             "max-message-size"
+                                             (list false? integer?
+                                                   string?)))))
+  ;; FIXME/TODO the sanitize function of sub-addr-delim should accept a
+  ;; string of length one not string?
+  (sub-addr-delim opensmtpd-smtp-sub-addr-delim
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp"
+                                           "sub-addr-delim"
+                                           (list false? integer? string?))))))
+
+(define-record-type* <opensmtpd-srs>
+  opensmtpd-srs make-opensmtpd-srs
+  opensmtpd-srs?
+  (key opensmtpd-srs-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-srs" "key"
+                                (list false? boolean? my-file-exists?)))))
+  (backup-key opensmtpd-srs-backup-key
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-srs" "backup-key"
+                                       (list false? integer?
+                                             my-file-exists?)))))
+  ;; TODO the user could set the string to be "zebra", which would break
+  ;; the config.
+  (ttl-delay opensmtpd-srs-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-srs" "ttl-delay"
+                                      (list false? string?))))))
+
+(define-record-type* <opensmtpd-queue>
+  opensmtpd-queue make-opensmtpd-queue
+  opensmtpd-queue?
+  (compression opensmtpd-queue-compression
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-queue" "compression"
+                                        (list boolean?)))))
+  (encryption opensmtpd-queue-encryption
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-queue" "encryption"
+                                       (list boolean? string?
+                                             my-file-exists?)))))
+  ;; TODO the user could set the string to be "zebra", which would break
+  ;; the config.
+  (ttl-delay opensmtpd-queue-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-queue" "ttl-delay"
+                                      (list false? string?))))))
 
 (define-record-type* <opensmtpd-configuration>
   opensmtpd-configuration make-opensmtpd-configuration
   opensmtpd-configuration?
-  (package     opensmtpd-configuration-package
-               (default opensmtpd))
+  (package opensmtpd-configuration-package
+           (default opensmtpd))
   (config-file opensmtpd-configuration-config-file
-               (default %default-opensmtpd-config-file))
+               (default #f))
+  ;; FIXME/TODO should I include a admd authservid entry?
+  (bounce opensmtpd-configuration-bounce
+          (default #f)
+          (sanitize
+           (lambda (var)
+             (cond ((false? var)
+                    var)
+                   ((and (list? var)
+                         (>= 4 (length var))
+                         (<= 1 (length var))
+                         (list-of-strings? var)
+                         (every (lambda (str)
+                                  (and (<= 2 (string-length str))
+                                       ;; last character of str is 's' or 'm'
+                                       ;; or 'h' or 'd'.
+                                       (member (string-take-right str 1)
+                                               (list "s" "m" "h" "d"))
+                                       ;; first part of str is an integer.
+                                       (integer?
+                                        (string->number
+                                         (string-take str
+                                                      (- (string-length str)
+                                                         1 ))))))
+                                var))
+                    var)
+                   (else
+                    ;; FIXME TODO I am getting a warning that says
+                    ;; possibly wrong number of arguments to `G_'
+                    ;; is one of the below lines to blame?
+                    (if (string? var)
+                        (report-error (G_ "(bounce \"~a\") is invalid.\n") var)
+                        (report-error (G_ "(bounce ~a) is invalid.\n") var))
+                    (display-hint (G_ "Try (bounce (list \"30m\" \"2h\"))\n"))
+                    (throw 'bad! var))))))
+  (cas opensmtpd-configuration-cas
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "cas"
+                                (list false? list-of-opensmtpd-ca?)))))
+
+  ;; list of many records of type opensmtpd-interface
+  (interfaces opensmtpd-configuration-interfaces
+              (default (list (opensmtpd-interface)))
+              (sanitize
+               (lambda (var)
+                 ;; This makes sure that no opensmtpd-interface is like this:
+                 ;; (opensmtpd-interface (senders #f) (masquerade #t)), which
+                 ;; is a syntax error.
+                 (define (correct-senders? interface)
+                   (not
+                    (and (not (opensmtpd-interface-senders interface))
+                         (opensmtpd-interface-masquerade interface))))
+
+                 (define fieldname "interface")
+
+                 ;; TODO rework this sanitize bit, so that if someone writes:
+                 ;; (opensmtpd-interface (senders #f) (masquerade #t)), they
+                 ;; get a proper error.
+                 ;; (report-error
+                 ;;  (G_ "((senders #f) & (masquerade #t)) is invalid.\n"))
+                 (if (and (list-of-interface? var)
+                          (every correct-senders? var)
+                          (not (contains-duplicate? var)))
+                     var
+                     (begin
+                       (display "<opensmtpd-configuration> fieldname ")
+                       (display  "'interface' may be #f or a list of records")
+                       (display "\n of unique <opensmtpd-interface>.\n")
+                       (throw 'bad! var))))))
+  (socket opensmtpd-configuration-socket
+                    (default #f)
+                    (sanitize
+                     (lambda (var)
+                       (define fieldname "socket")
+                       (if (or (opensmtpd-socket? var)
+                               (false? var))
+                           var
+                           (begin
+                             (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                           fieldname var)
+                             (display-hint
+                              (G_
+                               (string-append "Try an ("
+                                              fieldname
+                                              " (opensmtpd-socket ...)) .\n")))
+                             (throw 'bad! var))))))
+  ;; list of strings of absolute path names
+  (includes opensmtpd-configuration-includes
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-configuration" "includes"
+                                     (list false? list-of-strings? gexp?)))))
+  (matches opensmtpd-configuration-matches
+           (default (list (opensmtpd-match
+                           (action (opensmtpd-local-delivery
+                                    (name "local")
+                                    (method "mbox")))
+                           (options (list
+                                     (opensmtpd-option
+                                      (option "for local")))))
+                          (opensmtpd-match
+                           (action (opensmtpd-relay
+                                    (name "outbound")))
+                           (options (list
+                                     (opensmtpd-option
+                                      (option "from local"))
+                                     (opensmtpd-option
+                                      (option "for any")))))))
+           ;; TODO perhaps I should sanitize this function like I sanitized
+           ;; the 'filters'. For example, you could have two different.
+           ;; actions, one for local delivery and one for remote,
+           ;; with the same name.
+           ;; It might be a bit complicated to do this.
+           ;; I might just let smtpd figure out if the user made a silly
+           ;; mistake by having two different actions with the same name.
+           (sanitize (lambda (var)
+                       var
+                       (my/sanitize var "opensmtpd-configuration" "matches"
+                                    (list list-of-opensmtpd-match?)))))
+  ;; list of many records of type mda-wrapper
+  ;; TODO/FIXME support using gexps here
+  ;; eg (list "name" gexp)
+  ;; TODO what are mda-wrappers for?  How do I use this fieldname?
+  ;; (mda-wrappers opensmtpd-configuration-mda-wrappers
+  ;;               (default #f)
+  ;;               (sanitize (lambda (var)
+  ;;                           (my/sanitize var
+  ;;                                        "opensmtpd-configuration"
+  ;;                                        "mda-wrappers"
+  ;;                                        (list false? string?)))))
+  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
+                    (default 100)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-configuration"
+                                             "mta-max-deferred"
+                                             (list number?)))))
+  (queue opensmtpd-configuration-queue
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-configuration" "queue"
+                                  (list false? opensmtpd-queue?)))))
+  (smtp opensmtpd-configuration-smtp
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-configuration" "smtp"
+                                 (list false? opensmtpd-smtp?)))))
+  (srs opensmtpd-configuration-srs
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "srs"
+                                (list false? opensmtpd-srs?)))))
   (setgid-commands? opensmtpd-setgid-commands? (default #t)))
 
+;; this help procedure is used 3 or 4 times by
+;; sanitize-options-for-opensmtpd-match
+(define* (throw-error-duplicate-option option error-arg
+                                       #:key (record-name "match"))
+  (throw-error error-arg
+               (list
+                (string-append "(opensmtpd-" record-name
+                               ") (options ...)) can only have one \n"
+                               "(opensmtpd-option (option \"" option
+                               "\")) record, but more are present. \n"))
+               #:duplicate-option #t))
+
+;; this procedure sanitizes the fieldname opensmtpd-match-options
+(define* (sanitize-options-for-opensmtpd-match %options)
+  (define option-list (list "for any" "for local" "for domain"
+                            "for rcpt-to" "from any" "from auth"
+                            "from local" "from mail-from" "from rdns"
+                            "from socket" "from src" "auth" "helo"
+                            "mail-from" "rcpt-to" "tag" "tls"))
+  (when (not (list-of-opensmtpd-option? %options))
+    (report-error (G_ ""))
+    (display
+     (string-append "(opensmtpd-match (options ...)) is a list of unique"
+                    " (opensmtpd-option ...) records.\nIt's value is: "))
+    (display %options)
+    (display "\n")
+    (throw 'bad! %options))
+
+  (let loop ((%traversing-options %options)
+             ;; sanitized-options is an alist that may end of looking
+             ;; like:
+             ;; (("for" (opensmtpd-option (option "for any")))
+             ;;  ("from" (opensmtpd-option (option "from any")))
+             ;;  ("tag (opensmtpd-option (option "tag") (data "tag")))
+             (%sanitized-options '())
+             (option-record (if (null? %options)
+                                '()
+                                (car %options)))
+             (option-string (if (null? %options)
+                                '()
+                                (opensmtpd-option-option
+                                 (car %options)))))
+
+    (cond
+     ((null? %traversing-options)
+      %options)
+     ;; error if option-string is invalid option
+     ((not (member option-string option-list))
+      (report-error (G_ "(opensmtpd-match \"~a\")) is invalid.\n")
+                    option-string)
+      (display-hint (G_ ""))
+      (display (hint-string option-string option-list #:fieldname "option"))
+      (throw 'bad! option-string))
+     ;; error, if duplicate option
+     ((assoc-ref %sanitized-options option-string)
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-match (options ...)) can "
+                              "only have one (opensmtpd-option (option "
+                              "\"" option-string "\")), but more "
+                              " \n are present.\n"))
+      (display-hint
+       (format #f (G_ "Try removing one (opensmtpd-option (option \"~a\")).~%")
+        option-string))
+      (throw 'bad! option-record))
+     ;; error, if duplicate from or duplicate for option
+     ((or
+       (if (and (string=? "for" (substring option-string 0 3))
+                (assoc-ref %sanitized-options "for"))
+           #t
+           #f)
+       (if (and (>= (length (string->list option-string)) 4)
+                (string=? "from" (substring option-string 0 4))
+                (assoc-ref %sanitized-options "from"))
+           #t
+           #f))
+      (throw-error %options
+                   (list "(opensmtpd-match (options ...)) can only have one"
+                         " (option \"for ...\") and one (option \"from ...\")"
+                         "\nBut (option \"" option-string "\") and (option \""
+                         (opensmtpd-option-option
+                          (if (assoc-ref %sanitized-options "for")
+                              (assoc-ref %sanitized-options "for")
+                              (assoc-ref %sanitized-options "from")))
+                         "\") are present.\n")
+                   #:hint-strings
+                   (list "Try removing one "
+                         (if (string=? "for" (substring option-string 0 3))
+                             "(opensmtpd-option (option \"for ...\"))"
+                             "(opensmtpd-option (option \"from ...\"))")
+                         " record.\n")))
+     ;; these 3 options must have fieldname data defined.
+     ((and (member option-string
+                   (list "helo" "mail-from" "rcpt-to"))
+           (not (opensmtpd-option-data option-record)))
+      (report-error (G_ ""))
+      (display (string-append "(option \"" option-string
+                              "\") must have (data ...) of type string or an "
+                              "(opensmtpd-table ...) record.\n"))
+      (throw 'bad! option-string))
+     ;; fieldname data must be a string.
+     ((and (string=? "tag" option-string)
+           (not (string? (opensmtpd-option-data option-record))))
+      (throw-error option-record
+                   (list "(opensmtpd-match ... (option \"tag\"))"
+                         " must have a 'data' of type string.\n")))
+     ((or (string=? "tls" option-string)
+          (string=? "for" (substring option-string 0 3))
+          (string=? "from" (substring option-string 0 4)))
+      ;; let's test the "for" and "from" options now.
+      (cond
+       ;; the options in this list cannot define 'data' or 'regex'
+       ;; fieldnames.
+       ((and (member option-string (list "for local" "for any"
+                                         "from any" "from local"
+                                         "from socket" "tls"))
+             (or (opensmtpd-option-data option-record)
+                 (opensmtpd-option-regex option-record)))
+        (report-error (G_ ""))
+        (display (string-append "When (openmstpd-option (option \""
+                                option-string "\") ...), "
+                                "then (data ...) and (regex ...) "
+                                "must be #f. \n"))
+        (throw 'bad! option-record))
+       ;; the options in this list must have a data field of type
+       ;; string or tables-data-are-a-list-of-strings?
+       ((and (member option-string
+                     (list "for domain" "for rcpt-to"
+                           "from mail-from" "from src"))
+             (or (false? (opensmtpd-option-data option-record))
+                 (tables-data-are-assoc-list?
+                  (opensmtpd-option-data option-record))))
+        (throw-error option-record
+                     (list "When (openmstpd-option (option \""
+                           option-string "\") ...) \n"
+                           "then (data ...) must be a string or an \n"
+                           "(opensmtpd-table ....) record whose "
+                           "'data' is a list of strings.\n")))
+       (else
+        (loop (cdr %traversing-options)
+              (alist-cons
+               (cond ((string=? "for" (substring option-string 0 3))
+                      "for")
+                     ((string=? "tls" option-string)
+                      "tls")
+                     (else "from"))
+               option-record
+               %sanitized-options)
+              ;;option-record
+              (if (null? (cdr %traversing-options))
+                  '()
+                  (car (cdr %traversing-options)))
+              ;; option-string
+              (if (null? (cdr %traversing-options))
+                  '()
+                  (opensmtpd-option-option
+                   (car (cdr %traversing-options))))))))
+     ;; TODO if auth's 'data' is an assoc-list table, then
+     ;; it IS invalid!
+     ;; option-string = 'auth' cannot be made invalidly,
+     ;; do not test for it.
+     (else
+      (loop (cdr %traversing-options)
+            (alist-cons option-string option-record
+                        %sanitized-options)
+            ;;option-record
+            (if (null? (cdr %traversing-options))
+                '()
+                (car (cdr %traversing-options)))
+            ;; option-string
+            (if (null? (cdr %traversing-options))
+                '()
+                (opensmtpd-option-option
+                 (car (cdr %traversing-options)))))))))
+
+(define (filter-phase-has-message-and-value? record)
+  (and (opensmtpd-filter-phase-message record)
+       (opensmtpd-filter-phase-value record)))
+
+;; return #t if phase needs a message. Or if the message did not start
+;; with a 4xx or 5xx status code. otherwise #f
+(define (filter-phase-decision-lacks-proper-message? record)
+  (define decision (opensmtpd-filter-phase-decision record))
+  (if (member decision (list "disconnect" "reject"))
+      ;; this message needs to be RFC compliant, meaning
+      ;; that it need to start with 4xx or 5xx status code
+      (cond ((eq? #f (opensmtpd-filter-phase-message record))
+             #t)
+            ((string? (opensmtpd-filter-phase-message record))
+             (let ((number (string->number
+                            (substring
+                             (opensmtpd-filter-phase-message record) 0 3))))
+               (if (and (number? number)
+                        (and (< number 600) (> number 399)))
+                   #f
+                   #t))))
+      #f))
+
+;; 'decision' "rewrite" requires 'value' to be a number.
+(define (filter-phase-lacks-proper-value? record)
+  (define decision (opensmtpd-filter-phase-decision record))
+  (if (string=? "rewrite" decision)
+      (if (and (number? (opensmtpd-filter-phase-value record))
+               (eq? #f (opensmtpd-filter-phase-message record)))
+          #f
+          #t)
+      #f))
+
+;; 'decision' "junk" or "bypass" cannot have a message or a value.
+(define (filter-phase-has-incorrect-junk-or-bypass? record)
+  (and
+   (member
+    (opensmtpd-filter-phase-decision record)
+    (list "junk" "bypass"))
+   (or
+    (opensmtpd-filter-phase-value record)
+    (opensmtpd-filter-phase-message record))))
+
+(define (filter-phase-junks-after-commit? record)
+  (and (string=? "junk" (opensmtpd-filter-phase-decision record))
+       (string=? "commit" (opensmtpd-filter-phase-phase record))))
+
+;; returns #t if list is a unique list of <opensmtpd-filter> or
+;; <opensmtpd-filter-phase> returns # otherwise
+;; only opensmtpd-filter-chain? uses this function, and opensmtpd-filter-chain
+;; is NEVER actually used.
+;; I could possibly remove it.
+(define (list-of-unique-filter-or-filter-phase? %filters)
+  (and (list? %filters)
+       (not (null? %filters))
+       ;; this list is made up of only <opensmtpd-filter-phase>
+       ;; or <opensmtpd-filter>
+       (every (lambda (filter)
+                (or (opensmtpd-filter? filter)
+                    (opensmtpd-filter-phase? filter)))
+              %filters)
+       ;; each filter-name is unique.
+       (not (duplicate-filter-name %filters))))
+
+(define (filters->list-of-filter-names %filters)
+  (map (lambda (filter)
+         (cond ((opensmtpd-filter-phase? filter)
+                (opensmtpd-filter-phase-name filter))
+               (else (opensmtpd-filter-name filter))))
+       %filters))
+
+(define (duplicate-string-in-list strings)
+  (define first-string (car strings))
+  (cond ((null? (cdr strings))
+         #f)
+        ((any (lambda (element)
+                (if (string=? element first-string)
+                    element
+                    #f))
+              (cdr strings))
+         first-string)
+        (else (duplicate-string-in-list (cdr strings)))))
+
+(define (duplicate-filter-name %filters)
+  (define filter-names (filters->list-of-filter-names %filters))
+  (duplicate-string-in-list filter-names))
+
+;; the sanitize procedures used for sanitizing each <opensmtpd-interface> and
+;; <opensmtpd-socket> fieldname 'filters'.
+;; It primarily sanitizes <filter-phases>.  The only sanitization it does
+;; for <filter>s, is no make sure there are no duplicate filter names.
+
+(define* (sanitize-socket-and-interfaces-filters
+          %filters
+          #:key (socket-or-interface "interface"))
+
+  ;; if there are two filters with the same name, store that name here.
+  (define the-duplicate-filter-name
+    (if (not %filters)
+        #f
+        (duplicate-filter-name %filters)))
+
+  (define %filter-phases
+    (if (not %filters)
+        '()
+        (remove opensmtpd-filter? %filters)))
+  ;; the order of the first two tests in this cond is important.
+  ;; (false?) has to be 1st and (duplicate-filter-filter-name) has to be
+  ;; second. You may optionally re-order the other alternates in the cond.
+  (cond ((false? %filters)
+         #f)
+        (the-duplicate-filter-name
+         (report-error (G_ ""))
+         (display (string-append
+                   "(opensmtpd-" socket-or-interface
+                   " (filters ...)) has a duplicate filter name: \""
+                   the-duplicate-filter-name "\".\n"))
+         (throw 'bad! %filters))
+        (else
+         (let loop ((%traversing-list %filter-phases)
+                    (fieldname (if (null? %filter-phases)
+                                   '()
+                                   (opensmtpd-filter-phase-decision
+                                    (car %filter-phases)))))
+           (cond
+            ((null? %traversing-list)
+             %filters)
+            ((opensmtpd-filter? (car %traversing-list))
+             (loop (cdr %traversing-list)
+                   (if (null? (cdr %traversing-list))
+                       '()
+                       (opensmtpd-filter-phase-decision
+                        (car (cdr %traversing-list))))))
+            ((filter-phase-has-message-and-value?
+              (car %traversing-list))
+             (report-error (G_ ""))
+             (display
+              (string-append "(opensmtpd-filter-phase ...) cannot define "
+                             "fieldnames 'value' \n and 'message'.\n")))
+            ((filter-phase-decision-lacks-proper-message?
+              (car %traversing-list))
+             (cond
+              ((string? fieldname)
+               (report-error
+                (G_ "(decision \"~a\") with (message ...) is invalid.~%")
+                fieldname))
+              ((or (integer? fieldname) (boolean? fieldname))
+               (report-error
+                (G_ "(decision ~a) with (message ...) is invalid.~%")
+                fieldname))
+              (else
+               (report-error
+                (G_ "(~a ...\") with (message ...) is invalid.~%... is ~a")
+                fieldname)))
+             (display-hint
+              (G_ (string-append "Try (opensmtpd-filter-phase "
+                                 "(message \"406 Not acceptable.\") "
+                                 "(decision \"" fieldname "\")).\n")))
+             (throw 'bad! (car %traversing-list)))
+            ((filter-phase-lacks-proper-value? (car %traversing-list))
+             (begin
+               (report-error (G_ ""))
+               (display
+                (string-append
+                 "(opensmtpd-filter-phase (decision \"rewrite\")"
+                 "\n\t\t(value ...)) must be a number.\n"))
+               (display-hint (G_ "Try (value 5)."))
+               (throw 'bad! (car %traversing-list))))
+            ((filter-phase-has-incorrect-junk-or-bypass?
+              (car %traversing-list))
+             (begin
+               (report-error (G_ ""))
+               (display
+                (string-append "(opensmtpd-filter-phase (decision \""
+                               (opensmtpd-filter-phase-decision
+                                (car %traversing-list))
+                               "\") cannot define (message ...) or "
+                               "(value ...).\n"))
+               (throw 'bad! (car %traversing-list))))
+            ((filter-phase-junks-after-commit? (car %traversing-list))
+             (begin
+               (report-error (G_ ""))
+               (display
+                (string-append
+                 "(opensmtpd-filter-phase (decision \"junk\")\n\t\t "
+                 "(phase \"commit\")) is invalid.\n"))
+               (display-hint
+                (G_ (string-append "You cannot junk an email during phase "
+                                   "\"commit\". Try (phase \"data\").\n")))
+               (throw 'bad! (car %traversing-list))))
+            (else (loop (cdr %traversing-list)
+                        (if (null? (cdr %traversing-list))
+                            '()
+                            (opensmtpd-filter-phase-decision
+                             (car (cdr %traversing-list)))))))))))
+
+(define* (sanitize-options-for-filter-phase %options)
+  (define option-list
+    (list "fcrdns" "rdns" "src" "helo" "auth" "mail-from" "rcpt-to"))
+  (let loop ((%traversing-options %options)
+             ;; sanitized-options is an alist that may end of looking like:
+             ;; (("fcrdns" (opensmtpd-option (option "fcrdns")))
+             ;;  ("auth" (opensmtpd-option (option "auth"))))
+             (%sanitized-options '())
+             (option-record (if (null? %options)
+                                '()
+                                (car %options)))
+             (option-string (if (null? %options)
+                                '()
+                                (opensmtpd-option-option (car %options)))))
+    (cond
+     ((null? %traversing-options)
+      %options)
+     ;; error if option-string is invalid option
+     ((not (member option-string option-list))
+      (report-error
+       (G_ "(opensmtpd-filter-phase (option \"~a\")) is invalid.\n")
+       option-string)
+      (display-hint (G_ ""))
+      (display (hint-string option-string option-list
+                            #:fieldname "option"))
+      (throw 'bad! option-string))
+
+     ;; if we see two "rdns" (for example), throw a
+     ;; "duplicate option" error.
+     ((assoc-ref %sanitized-options option-string)
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-filter-phase (options ...)) can "
+                              "only have one\n (opensmtpd-option (option \""
+                              option-string "\")), but more are present.\n"))
+      (display-hint
+       (format #f (G_ "Try removing one (option \"~a\").~%") option-string))
+      (throw 'bad! option-record))
+
+     ;; the next 4 options must have fieldname 'data' defined.
+     ((and (member option-string
+                   (list "src" "helo" "mail-from" "rcpt-to"))
+           (not (opensmtpd-table? (opensmtpd-option-data option-record))))
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-filter-phase ... " "(option \""
+                              option-string "\")) must define (data ...).\n"))
+      (display-hint (G_ "Try defining (data (opensmtpd-table ...).\n"))
+      (throw 'bad! option-record))
+     ;;fcrdns cannot have fieldname data defined
+     ((and (string=? "fcrdns" option-string)
+           (opensmtpd-option-data option-record))
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-option \"" option-string "\") "
+                              "cannot define (data ...).\n"))
+      (display-hint (G_ ""))
+      (display "Try removing (data ...).\n")
+      (throw 'bad! option-record))
+     ;; rdns and auth cannot be made invalidly.
+     ;; skip testing them.
+     (else (loop (cdr %traversing-options)
+                 (alist-cons option-string option-record
+                             %sanitized-options)
+                 ;; option-record
+                 (if (null? (cdr %traversing-options))
+                     '()
+                     (car (cdr %traversing-options)))
+                 ;; option-string
+                 (if (null? (cdr %traversing-options))
+                     '()
+                     (opensmtpd-option-option
+                      (car (cdr %traversing-options)))))))))
+
+(define* (throw-error var %strings
+                      #:key
+                      (record-name #f)
+                      (duplicate-option #f)
+                      (fieldname #f)
+                      (hint-strings #f))
+  (cond ((and record-name fieldname)
+         (cond ((or (string? var))
+                (report-error (G_ "(~a \"~a\") is invalid.~%") fieldname var))
+               ((boolean? var)
+                (report-error (G_ "(~a ~a) is invalid.~%") fieldname var))
+               ((number? var)
+                (report-error (G_ "(~a ~a) is invalid.~%") fieldname
+                              (number->string var)))
+               (else
+                (report-error (G_ "(~a ...) is invalid.~%Its value is: ~a~%")
+                              fieldname var)))
+         (display-hint (G_ (string-append "(opensmtpd-" record-name
+                                          " (fieldname " fieldname "...)) "
+                                          (apply string-append %strings))))
+         (throw 'bad! var))
+        ((list? hint-strings)
+         (report-error (G_ ""))
+         (display (apply string-append %strings))
+         (display-hint (G_ (apply string-append hint-strings)))
+         (throw 'bad! var))
+        ;; display the output for throw-error-duplicate-option
+        (duplicate-option
+         (report-error (G_ ""))
+         (display (apply string-append %strings))
+         (display-hint
+          (format #f
+                  (G_ "Try removing one (opensmtpd-option \"~a\") option.\n")
+                               var))
+         (throw 'bad! var))
+        (else
+         (report-error (G_ ""))
+         (display (apply string-append %strings))
+         (throw 'bad! var))))
+
+;; if strings is (list "auth" "for any" "from local")
+;; Then this will return "Try \"auth\", \"for any\", or \"from local\".
+(define (try-string strings)
+  (string-append "Try "
+                 (let loop ((strings strings))
+                   (cond ((= 1 (length strings))
+                          (string-append
+                           "or \"" (car strings) "\".\n"))
+                         (else
+                          (string-append
+                           "\"" (car strings) "\", "
+                           (loop (cdr strings))))))))
+
+;; suppose string is "for anys"
+;; and strings is (list "for any" "for local" "for domain")
+;; then hint-string will return "Did you mean "for any"?"
+(define* (hint-string string strings
+                      #:key (fieldname #f))
+  (define str (string-closest string strings))
+  (if (not str)
+      (try-string strings)
+      (if fieldname
+          (string-append "Did you mean (" fieldname " \""
+                         str "\") ?\n")
+          (string-append "Did you mean  \"" str "\" ?\n"))))
+
+;; this is used for sanitizing <opensmtpd-filter-phase> fieldname 'options'
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+      ;; check if (car list) is in (cdr list)
+      (any (lambda (var)
+             (equal? var (car list)))
+           (cdr list))
+       ;; check if (cdr list) contains duplicate
+       (contains-duplicate? (cdr list)))))
+
+(define* (variable->string var #:key (append "") (postpend " "))
+  (let ((var (if (number? var)
+                 (number->string var)
+                 var)))
+    (if var
+        (string-append append var postpend)
+        "")))
+
+;;; Various functions to check that lists are of the appropriate type.
+
+;; given a list and procedure, this tests that each element of list is of type
+;; ie: (list-of-type? list string?) tests each list is of type string.
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ((list list))
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+
+(define (list-of-strings? list)
+  (list-of-type? list string?))
+
+(define (list-of-interface? list)
+  (list-of-type? list opensmtpd-interface?))
+
+(define (list-of-opensmtpd-option? list)
+  (list-of-type?
+   list opensmtpd-option?))
+
+(define (list-of-opensmtpd-ca? list)
+  (list-of-type? list opensmtpd-ca?))
+
+(define (list-of-opensmtpd-pki? list)
+  (list-of-type? list opensmtpd-pki?))
+
+(define (list-of-opensmtpd-match? list)
+  (list-of-type? list opensmtpd-match?))
+
+(define* (list-of-strings->string list
+                                  #:key
+                                  (string-delimiter ", ")
+                                  (postpend "")
+                                  (append "")
+                                  (drop-right-number 2))
+  (string-drop-right
+   (string-append (let loop ((list list))
+                    (if (null? list)
+                        ""
+                        (string-append append (car list) postpend
+                                       string-delimiter
+                                       (loop (cdr list)))))
+                  append)
+   drop-right-number))
+
+;; TODO I should probably change this to alist, because that's what this is.
+(define (assoc-list? assoc-list)
+  (list-of-type? assoc-list
+                 (lambda (pair)
+                   (and (pair? pair)
+                        (string? (car pair))
+                        (string? (cdr pair))
+                        (<= 1 (string-length (car pair)))
+                        (<= 1 (string-length (cdr pair)))))))
+
+(define (nested-list? list)
+  (every (lambda (element)
+           (and
+            (list-of-strings? element)
+            (< 1 (length element))))
+         list))
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table> whose fieldname 'values' is
+;; an assoc-list, then it returns #t, #f if otherwise.
+(define (tables-data-are-assoc-list? table)
+  (if (not (opensmtpd-table? table))
+      #f
+      (assoc-list? (opensmtpd-table-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table> whose fieldname 'values' is a
+;; list of strings, then it returns #t, #f if otherwise.
+(define (tables-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table? table))
+      #f
+      (and (list-of-strings? (opensmtpd-table-data table)))))
+
+;; This procedures takes in an <opensmtpd-table>
+;; if that table a list of lists of strings eg:
+;; (list (list "cat") (list "dog"))
+;; then this returns #t, otherwise false.
+(define (tables-data-are-a-nested-list-of-strings? table)
+  (cond ((false? (opensmtpd-table-data table))
+         #f)
+        ((not (list? (opensmtpd-table-data table)))
+         #f)
+        (else
+         (nested-list? (opensmtpd-table-data table)))))
+
+;;; The following functions convert various records into strings.
+
+;; these next few functions help me to turn <table>s
+;; into strings suitable to fit into "opensmtpd.conf".
+(define (assoc-list->string assoc-list)
+  (string-drop-right
+   (let loop ((assoc-list assoc-list))
+     (if (null? assoc-list)
+         ""
+         ;; pair is (cons "hello" "world") -> ("hello" . "world")
+         (let ((pair (car assoc-list)))
+           (string-append
+            "\"" (car pair)  "\""
+            " = "
+            "\"" (cdr pair) "\""
+            ", "
+            (loop (cdr assoc-list))))))
+   2))
+
+;; can be of type: (quote list-of-strings) or (quote assoc-list)
+;;  this will output a string that looks like:
+;;  table <"mytable"> { "ludo"="ludo@gnu.org" }
+(define (opensmtpd-table->string table)
+  (string-append "table \"" (opensmtpd-table-name table) "\" "
+                 (cond ((tables-data-are-a-list-of-strings? table)
+                        (string-append "{ "
+                                       (list-of-strings->string
+                                        (opensmtpd-table-data table)
+                                        #:append "\""
+                                        #:drop-right-number 3
+                                        #:postpend "\"") " }"))
+                       ((tables-data-are-assoc-list? table)
+                        (string-append "{ "
+                                       (assoc-list->string
+                                        (opensmtpd-table-data table)) " }"))
+                       (else (throw 'youMessedUp table)))
+                 " \n"))
+
+;; will output something like:
+;; <"mytable">
+(define (opensmtpd-table-name->string table)
+  (string-append "<\"" (opensmtpd-table-name table) "\">"))
+
+(define (opensmtpd-interface->string record)
+  (string-append
+   "listen on "
+   (opensmtpd-interface-interface record) " "
+   (let* ((hostname (opensmtpd-interface-hostname record))
+          (hostnames (if (opensmtpd-interface-hostnames record)
+                         (opensmtpd-table-name
+                          (opensmtpd-interface-hostnames record))
+                         #f))
+          (filters (opensmtpd-interface-filters record))
+          (filter-name (if filters
+                           (if (< 1 (length filters))
+                               (generate-filter-chain-name filters)
+                               (if (opensmtpd-filter? (car filters))
+                                   (opensmtpd-filter-name (car filters))
+                                   (opensmtpd-filter-phase-name
+                                    (car filters))))
+                           #f))
+          (mask-src (opensmtpd-interface-mask-src record))
+          (tag (opensmtpd-interface-tag record))
+          (senders (opensmtpd-interface-senders record))
+          (masquerade (opensmtpd-interface-masquerade record))
+          (secure-connection (opensmtpd-interface-secure-connection record))
+          (port (opensmtpd-interface-port record))
+          (pki (opensmtpd-interface-pki record))
+          (auth (opensmtpd-interface-auth record))
+          (auth-optional (opensmtpd-interface-auth-optional record)))
+     (string-append
+      (if mask-src
+          (string-append "mask-src ")
+          "")
+      (variable->string hostname #:append "hostname ")
+      (variable->string hostnames #:append "hostnames <" #:postpend "> ")
+      (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+      (variable->string tag #:append "tag \"" #:postpend "\" ")
+      (if secure-connection
+          (cond ((string=? "smtps" secure-connection)
+                 "smtps ")
+                ((string=? "tls" secure-connection)
+                 "tls ")
+                ((string=? "tls-require" secure-connection)
+                 "tls-require ")
+                ((string=? "tls-require-verify" secure-connection)
+                 "tls-require verify "))
+          "")
+      (if senders
+          (string-append "senders <\"" (opensmtpd-table-name senders) "\"> "
+           (if masquerade
+               "masquerade "
+               ""))
+          "")
+      (variable->string port #:append "port " #:postpend " ")
+      (if pki
+          (variable->string (opensmtpd-pki-domain pki) #:append "pki ")
+          "")
+      (if auth
+          (string-append "auth "
+                         (if (opensmtpd-table? auth)
+                             (string-append
+                              (opensmtpd-table-name->string auth))
+                             ""))
+          "")
+      (if auth-optional
+          (string-append "auth-optional "
+                         (if (opensmtpd-table? auth-optional)
+                             (string-append
+                              "<\""
+                              (opensmtpd-table-name->string auth-optional)
+                              "\">")
+                             ""))
+          "")
+      "\n"))))
+
+(define (opensmtpd-socket->string record)
+  (string-append
+   "listen on socket "
+   (let* ((filters (opensmtpd-socket-filters record))
+          (filter-name (if filters
+                           (if (< 1 (length filters))
+                               (generate-filter-chain-name filters)
+                               (if (opensmtpd-filter? (car filters))
+                                   (opensmtpd-filter-name (car filters))
+                                   (opensmtpd-filter-phase-name
+                                    (car filters))))
+                           #f))
+          (mask-src (opensmtpd-socket-mask-src record))
+          (tag (opensmtpd-socket-tag record)))
+     (string-append
+      (if mask-src
+          (string-append "mask-src ")
+          "")
+      (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+      (variable->string tag #:append "tag \"" #:postpend "\" ")
+      "\n"))))
+
+(define (opensmtpd-relay->string record)
+  (let ((backup (opensmtpd-relay-backup record))
+        (backup-mx (opensmtpd-relay-backup-mx record))
+        (helo (opensmtpd-relay-helo record))
+        ;; helo-src can either be a string IP address or an <opensmtpd-table>
+        (helo-src (if (opensmtpd-relay-helo-src record)
+                      (if (string? (opensmtpd-relay-helo-src record))
+                          (opensmtpd-relay-helo-src record)
+                          (string-append "<\""
+                                         (opensmtpd-table-name
+                                          (opensmtpd-relay-src record))
+                                         "\">"))
+                      #f))
+        (domain (if (opensmtpd-relay-domain record)
+                    (opensmtpd-table-name
+                     (opensmtpd-relay-domain record))
+                    #f))
+        (host (opensmtpd-relay-host record))
+        (name (opensmtpd-relay-name record))
+        (pki (if (opensmtpd-relay-pki record)
+                 (opensmtpd-pki-domain (opensmtpd-relay-pki record))
+                 #f))
+        (srs (opensmtpd-relay-srs record))
+        (tls (opensmtpd-relay-tls record))
+        (auth (if (opensmtpd-relay-auth record)
+                  (opensmtpd-table-name
+                   (opensmtpd-relay-auth record))
+                  #f))
+        (mail-from (opensmtpd-relay-mail-from record))
+        ;; src can either be a string IP address or an <opensmtpd-table>
+        (src (if (opensmtpd-relay-src record)
+                 (if (string? (opensmtpd-relay-src record))
+                     (opensmtpd-relay-src record)
+                     (string-append "<\""
+                                    (opensmtpd-table-name
+                                     (opensmtpd-relay-src record))
+                                    "\">"))
+                 #f)))
+
+    (string-append
+     "\""
+     name
+     "\" " "relay "
+     ;;FIXME should I always quote the host fieldname?
+     ;; do I need to quote localhost via "localhost" ?
+     (variable->string host #:append "host \"" #:postpend "\" ")
+     (variable->string backup)
+     (variable->string backup-mx #:append "backup mx ")
+     (variable->string helo #:append "helo ")
+     (variable->string helo-src #:append "helo-src ")
+     (variable->string domain #:append "domain <\"" #:postpend "\"> ")
+     (variable->string host #:append "host ")
+     (variable->string pki #:append "pki ")
+     (variable->string srs)
+     (variable->string tls #:append "tls ")
+     (variable->string auth #:append "auth <\"" #:postpend "\"> ")
+     (variable->string mail-from #:append "mail-from ")
+     (variable->string src #:append "src ")
+     "\n")))
+
+(define (opensmtpd-lmtp->string record)
+  (string-append "lmtp "
+                 (opensmtpd-lmtp-destination record)
+                 (if (opensmtpd-lmtp-rcpt-to record)
+                     (begin
+                       " " (opensmtpd-lmtp-rcpt-to record))
+                     "")))
+
+(define (opensmtpd-mda->string record)
+  (string-append "mda "
+                 (opensmtpd-mda-command record) " "))
+
+(define (opensmtpd-maildir->string record)
+  (string-append "maildir "
+                 "\""
+                 (if (opensmtpd-maildir-pathname record)
+                     (opensmtpd-maildir-pathname record)
+                     "~/Maildir")
+                 "\""
+                 (if (opensmtpd-maildir-junk record)
+                     " junk "
+                     " ")))
+
+(define (opensmtpd-local-delivery->string record)
+  (let ((name (opensmtpd-local-delivery-name record))
+        (method (opensmtpd-local-delivery-method record))
+        (alias (if (opensmtpd-local-delivery-alias record)
+                   (opensmtpd-table-name
+                    (opensmtpd-local-delivery-alias record))
+                   #f))
+        (ttl (opensmtpd-local-delivery-ttl record))
+        (user (opensmtpd-local-delivery-user record))
+        (userbase (if (opensmtpd-local-delivery-userbase record)
+                      (opensmtpd-table-name
+                       (opensmtpd-local-delivery-userbase record))
+                      #f))
+        (virtual (if (opensmtpd-local-delivery-virtual record)
+                     (opensmtpd-table-name
+                      (opensmtpd-local-delivery-virtual record))
+                     #f))
+        (wrapper (opensmtpd-local-delivery-wrapper record)))
+    (string-append
+     "\"" name "\" "
+     (cond ((string? method)
+            (string-append method " "))
+           ((opensmtpd-mda? method)
+            (opensmtpd-mda->string method))
+           ((opensmtpd-lmtp? method)
+            (opensmtpd-lmtp->string method))
+           ((opensmtpd-maildir? method)
+            (opensmtpd-maildir->string method)))
+     ;; FIXME/TODO support specifying alias file:/path/to/alias-file  ?
+     ;; I do not think that is something that I can do...
+     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
+     (variable->string ttl #:append "ttl ")
+     (variable->string user #:append "user ")
+     (variable->string userbase #:append "userbase <\"" #:postpend "\"> ")
+     (variable->string virtual #:append "virtual <\"" #:postpend "\"> ")
+     (variable->string wrapper #:append "wrapper "))))
+
+;; this function turns both opensmtpd-local-delivery and
+;; opensmtpd-relay into strings.
+(define (opensmtpd-action->string record)
+  (string-append "action "
+                 (cond ((opensmtpd-local-delivery? record)
+                        (opensmtpd-local-delivery->string record))
+                       ((opensmtpd-relay? record)
+                        (opensmtpd-relay->string record)))
+                 " \n"))
+
+;; this turns option records found in <opensmtpd-match> into strings.
+(define* (opensmtpd-option->string record
+                                                 #:key
+                                                 (space-after-! #f))
+  (let ((bool (opensmtpd-option-bool record))
+        (option (opensmtpd-option-option record))
+        (regex (opensmtpd-option-regex record))
+        (data (opensmtpd-option-data record)))
+    (string-append
+     (if (false? bool)
+         (if space-after-!
+             "! "
+             "!")
+         "")
+     option " "
+     (if regex
+         "regex "
+         "")
+     (if data
+         (if (opensmtpd-table? data)
+             (string-append
+              (opensmtpd-table-name->string data) " ")
+             (string-append data " "))
+         ""))))
+
+(define (opensmtpd-match->string record)
+  (string-append "match "
+                 (let* ((action (opensmtpd-match-action record))
+                        (name (cond ((opensmtpd-relay? action)
+                                     (opensmtpd-relay-name action))
+                                    ((opensmtpd-local-delivery? action)
+                                     (opensmtpd-local-delivery-name action))
+                                    (else 'reject)))
+                        (options (opensmtpd-match-options record)))
+                   (string-append
+                    (if options
+                        (apply string-append
+                               (map opensmtpd-option->string options))
+                        "")
+                    (if (string? name)
+                        (string-append "action " "\"" name "\" ")
+                        "reject ")
+                    "\n"))))
+
+(define (opensmtpd-ca->string record)
+  (string-append "ca " (opensmtpd-ca-name record) " "
+                 "cert \"" (opensmtpd-ca-file record) "\"\n"))
+
+(define (opensmtpd-pki->string record)
+  (let ((domain (opensmtpd-pki-domain record))
+        (cert (opensmtpd-pki-cert record))
+        (key (opensmtpd-pki-key record))
+        (dhe (opensmtpd-pki-dhe record)))
+    (string-append "pki " domain " " "cert \"" cert "\" \n"
+                   "pki " domain " " "key \"" key "\" \n"
+                   (if dhe
+                       (string-append
+                        "pki " domain " " "dhe " dhe "\n")
+                       ""))))
+
+(define (generate-filter-chain-name list-of-filters)
+  (string-drop-right (apply string-append
+                            (flatten
+                             (map (lambda (filter)
+                                    (list
+                                     (if (opensmtpd-filter? filter)
+                                         (opensmtpd-filter-name filter)
+                                         (opensmtpd-filter-phase-name filter))
+                                     "-"))
+                                  list-of-filters)))
+                     1))
+
+(define (opensmtpd-filter->list-of-strings-and-gexps record)
+  (list "filter "
+        "\"" (opensmtpd-filter-name record) "\" "
+        (if (opensmtpd-filter-exec record)
+            "proc-exec "
+            "proc ")
+        "\"" (opensmtpd-filter-proc record) "\""
+        "\n\n"))
+
+;; this procedure takes in a list of <opensmtpd-filter> and
+;; <opensmtpd-filter-phase>. It returns a string of the form:
+;; filter "uniqueName" chain chain { "filter-name", "filter-name2" [, ...]}
+(define (opensmtpd-filter-chain->string list-of-filters)
+  (string-append "filter \""
+                 (generate-filter-chain-name list-of-filters)
+                 "\" "
+                 "chain {"
+                 (string-drop-right
+                  (apply string-append
+                         (flatten
+                          (map (lambda (filter)
+                                 (list
+                                  "\""
+                                  (if (opensmtpd-filter? filter)
+                                      (opensmtpd-filter-name filter)
+                                      (opensmtpd-filter-phase-name filter))
+                                  "\", "))
+                               list-of-filters)))
+                  2)
+                 "}\n\n"))
+
+(define (opensmtpd-filter-phase->string record)
+  (let ((name (opensmtpd-filter-phase-name record))
+        (phase (opensmtpd-filter-phase-phase record))
+        (decision (opensmtpd-filter-phase-decision record))
+        (options (opensmtpd-filter-phase-options record))
+        (message (opensmtpd-filter-phase-message record))
+        (value (opensmtpd-filter-phase-value record)))
+    (string-append "filter "
+                   "\"" name "\" "
+                   "phase " phase " "
+                   "match "
+                   (apply string-append ; turn the options into a string
+                          (flatten
+                           (map (lambda (option)
+                                  (opensmtpd-option->string
+                                   option #:space-after-! #f))
+                                options)))
+                   " "
+                   decision " "
+                   (if (member decision (list "reject" "disconnect"))
+                       (string-append "\"" message "\"")
+                       "")
+                   (if (string=? "rewrite" decision)
+                       (string-append "rewrite " (number->string value))
+                       "")
+                   "\n\n")))
+
+;; in the next procedure, the variable 'filters' is a list of
+;; <opensmtpd-filter>, <opensmtpd-filter-phase>, and filter chains, which are
+;; lists that look like:
+;; (list (opensmtpd-filter ...) (opensmtpd-filter-phase ...)
+;;       (opensmtpd-filter-phase ...) (opensmtpd-filter ...))
+;; This function converts (get-opensmtpd-filters <opensmtpd-configuration>)
+;; to a string.
+;; Consider if a user passed in a valid <opensmtpd-configuration>,
+;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
+;; (list (opensmtpd-filter
+;;         (name "rspamd")
+;;         (proc "rspamd"))
+;;       ;; this is a listen-on, with a filter-chain.
+;;       (list (opensmtpd-filter-phase
+;;               (name "dkimsign")
+;;               ...)
+;;               (opensmtpd-filter
+;;                 (name "rspamd")
+;;                 (proc "rspamd"))))
+;;
+;; (we will call the above list "total filters"):
+;; did you notice that filter "rspamd" is listed twice?  Once by itself, and
+;; once again in a filter chain. How do you make sure that it is NOT printed
+;; twice in smtpd.conf?
+;; 1st flatten "total filters", then remove its duplicates so that we
+;; may print the <opensmtpd-filter>s and <opensmtpd-filter-phase>s.
+;; 2nd now we go through "total filters", and we only print the filter-chains.
+(define (opensmtpd-filters->list-of-strings-and-gexps filters)
+  ;; first print the unique <opensmtpd-filter-phase>s and <opensmtpd-filter>s.
+  ;; then print the filter-chains.
+  ;; to do this: flatten filters, then remove duplicates.
+  (flatten
+   (list
+    ;; TODO for funsies, try to figure out how to list the filter-phases and
+    ;; filters in one go.  I tried it earlier, and it broke the service.
+    ;; Why?
+    ;;
+
+    ;; print the filter-phases
+    (apply string-append
+           (map (lambda (filter)
+                  (cond ((opensmtpd-filter-phase? filter)
+                         (opensmtpd-filter-phase->string filter))
+                        (else "")))
+                (delete-duplicates (flatten filters))))
+
+    ;; list the filters that may be gexps
+    (map (lambda (filter)
+           (cond ((opensmtpd-filter? filter)
+                  (opensmtpd-filter->list-of-strings-and-gexps filter))
+                 (else "")))
+         (delete-duplicates (flatten filters)))
+
+     ;; now we have to print the filter chains.
+    (apply string-append
+           (map (lambda (filter)
+                  (cond ((list? filter)
+                         (opensmtpd-filter-chain->string filter))
+                        (else            ; you are a <opensmtpd-filter>
+                         "")))
+                filters)))))
+
+(define (opensmtpd-configuration-includes->string string)
+  (string-append
+   "include \"" string "\"\n"))
+
+(define (opensmtpd-configuration-srs->string record)
+  (let ((key (opensmtpd-srs-key record))
+        (backup-key (opensmtpd-srs-backup-key record))
+        (ttl-delay (opensmtpd-srs-ttl-delay record)))
+    (string-append
+     (variable->string key #:append "srs key " #:postpend "\n")
+     (variable->string backup-key #:append "srs key backup " #:postpend "\n")
+     (variable->string ttl-delay #:append "srs ttl " #:postpend "\n")
+     "\n")))
+
+;; TODO make sure all options here work!  I just fixed limit-max-rcpt!
+(define (opensmtpd-smtp->string record)
+  (let ((ciphers (opensmtpd-smtp-ciphers record))
+        (limit-max-mails (opensmtpd-smtp-limit-max-mails record))
+        (limit-max-rcpt (opensmtpd-smtp-limit-max-rcpt record))
+        (max-message-size (opensmtpd-smtp-max-message-size record))
+        (sub-addr-delim (opensmtpd-smtp-sub-addr-delim record)))
+    (string-append
+     (variable->string ciphers #:append "smtp ciphers " #:postpend "\n")
+     (variable->string limit-max-mails
+                       #:append "smtp limit max-mails " #:postpend "\n")
+     (variable->string limit-max-rcpt
+                       #:append "smtp limit max-rcpt " #:postpend "\n")
+     (variable->string max-message-size
+                       #:append "smtp max-message-size " #:postpend "\n")
+     (variable->string sub-addr-delim
+                       #:append "smtp sub-addr-delim " #:postpend "\n")
+     "\n")))
+
+(define (opensmtpd-configuration-queue->string record)
+  (let ((compression (opensmtpd-queue-compression record))
+        (encryption (opensmtpd-queue-encryption record))
+        (ttl-delay (opensmtpd-queue-ttl-delay record)))
+    (string-append
+     (if compression
+         "queue compression\n"
+         "")
+     (if encryption
+         (string-append
+          "queue encryption "
+          (if (not (boolean? encryption))
+              encryption
+              "")
+          "\n")
+         "")
+     (if ttl-delay
+         (string-append "queue ttl" ttl-delay "\n")
+         ""))))
+
+;; build a list of <opensmtpd-action> from
+;; opensmtpd-configuration-matches, which is a list of <opensmtpd-match>.
+;; Each <opensmtpd-match> has a fieldname 'action', which accepts
+;; an <opensmtpd-action>.
+(define (get-opensmtpd-actions record)
+  (define opensmtpd-actions
+    (let loop ((list (opensmtpd-configuration-matches record)))
+      (if (null? list)
+          '()
+          (cons (opensmtpd-match-action (car list))
+                (loop (cdr list))))))
+  (delete-duplicates (append opensmtpd-actions)))
+
+;; build a list of opensmtpd-pkis from
+;; opensmtpd-configuration-interfaces and
+;; get-opensmtpd-actions
+(define (get-opensmtpd-pkis record)
+  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT have an
+  ;; opensmtpd-relay?
+  ;; I think so.  And if it did NOT have a relay configuration, then
+  ;; action-pkis would be '() when it needs to be #f.  because if the
+  ;; opensmtpd-configuration has NO pkis, then this function will
+  ;; return '(), when it should return #f.  If it returns '(), then
+  ;; opensmtpd-configuration-fieldname->string will
+  ;; print the string "\n" instead of ""
+  (define action-pkis
+    (let loop1 ((list (get-opensmtpd-actions record)))
+      (if (null? list)
+          '()
+          (if (and (opensmtpd-relay? (car list))
+                   (opensmtpd-relay-pki (car list)))
+              (cons (opensmtpd-relay-pki (car list))
+                    (loop1 (cdr list)))
+              (loop1 (cdr list))))))
+  ;; FIXME/TODO/maybe/wishlist
+  ;; this could be #f aka left blank. aka there are no interface records
+  ;; with pkis. aka there are no lines in the configuration like:
+  ;; listen on eth0 tls pki smtp.gnucode.me
+  ;; in that case the smtpd.conf will have an extra "\n"
+  (define listen-on-pkis
+    (let loop2 ((list (opensmtpd-configuration-interfaces record)))
+      (if (null? list)
+          '()
+          (if (opensmtpd-interface-pki (car list))
+              (cons (opensmtpd-interface-pki (car list))
+                    (loop2 (cdr list)))
+              (loop2 (cdr list))))))
+  (delete-duplicates (append action-pkis listen-on-pkis)))
+
+;; takes in a <opensmtpd-configuration> and returns a list whose
+;; elements are <opensmtpd-filter>, <opensmtpd-filter-phase>,
+;; and a filter-chain.
+;; It returns a list of <opensmtpd-filter> and/or <opensmtpd-filter-phase>
+;; here's an example of what this procedure might return:
+;; (list (opensmtpd-filter...) (opensmtpd-filter-phase ...)
+;;       (openmstpd-filter ...) (opensmtpd-filter-phase ...)
+;;       ;; this next list is a filter-chain.
+;;       (list (opensmtpd-filter-phase ...) (opensmtpd-filter...)))
+;;
+;; This procedure handles filter chains a little odd.
+(define (get-opensmtpd-filters record)
+  (define socket-filters
+    (if (and (opensmtpd-configuration-socket record)
+             (opensmtpd-socket-filters
+              (opensmtpd-configuration-socket record)))
+        (opensmtpd-socket-filters (opensmtpd-configuration-socket record))
+        '()))
+  (define list-of-interfaces
+    (if (opensmtpd-configuration-interfaces record)
+        (opensmtpd-configuration-interfaces record)
+        '()))
+
+  (delete-duplicates
+   (append
+    (remove boolean?
+            (map-in-order
+             ;; get the filters found in the <listen-on-record>s
+             (lambda (interface-or-socket-record)
+               (if (and
+                    (opensmtpd-interface-filters interface-or-socket-record)
+                    (= 1 (length (opensmtpd-interface-filters
+                                  interface-or-socket-record))))
+                   ;; this next line returns an <opensmtpd-interface>
+                   (car (opensmtpd-interface-filters
+                         interface-or-socket-record))
+                   ;; this next line returns a filter chain.
+                   (opensmtpd-interface-filters interface-or-socket-record)))
+             list-of-interfaces))
+    socket-filters)))
+
+(define (flatten . lst)
+  "Return a list that recursively concatenates all sub-lists of LST."
+  (define (flatten1 head out)
+    (if (list? head)
+        (fold-right flatten1 out head)
+        (cons head out)))
+  (fold-right flatten1 '() lst))
+
+;; This function takes in a record, or list, or anything, and returns
+;; a list of <opensmtpd-table>s assuming the thing you passed into it had
+;; any <opensmtpd-table>s.
+;;
+;; is object record? call func on it's fieldnames
+;; is object list? loop through it's fieldnames calling func on it's records
+;; is object #f or string? or '()? -> #f
+(define (get-opensmtpd-tables value)
+  (delete-duplicates
+   (remove boolean?
+           (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+            (cond ((opensmtpd-table? value)
+                   value)
+                  ((record? value)
+                   (let* ((record-type (record-type-descriptor value))
+                          (list-of-record-fieldnames
+                           (record-type-fields record-type)))
+                     (map (lambda (fieldname)
+                            (get-opensmtpd-tables
+                             ((record-accessor record-type fieldname)
+                              value)))
+                          list-of-record-fieldnames)))
+                  ((and (list? value) (not (null? value)))
+                   (map get-opensmtpd-tables value))
+                  (else #f))))))
+
+(define (opensmtpd-configuration-fieldname->string
+         record fieldname-accessor record->string)
+  (if (fieldname-accessor record)
+      (begin
+        (string-append
+         (list-of-records->string (fieldname-accessor record)
+                                  record->string) "\n"))
+      ""))
+
+(define (list-of-records->string list-of-records record->string)
+  (string-append
+   (cond ((not (list? list-of-records))
+          (record->string list-of-records))
+         (else
+          (let loop ((list list-of-records))
+            (if (null? list)
+                ""
+                (string-append
+                 (record->string (car list))
+                 (loop (cdr list)))))))))
+
+(define (opensmtpd-configuration->string record)
+  ;; should I use this named let, or should I give this a name, or
+  ;; not use it at all...
+  ;; eg:
+  ;; (write-all-fieldnames
+  ;;   (list (cons fieldname fieldname->string)
+  ;;         (cons fieldname2 fieldname->string)))
+  ;; (let loop ([list
+  ;;            (list
+  ;;              (cons opensmtpd-configuration-includes
+  ;;                    (lambda (string)
+  ;;                      (string-append
+  ;;                        "include \"" string "\"\n")))
+  ;;              (cons opensmtpd-configuration-smtp opensmtpd-smtp->string)
+  ;;              (cons opensmtpd-configuration-srs opensmtpd-srs->string))])
+  ;;   (if (null? list)
+  ;;       ""
+  ;;       (string-append
+  ;;         (opensmtpd-configuration-fieldname->string record
+  ;;          (caar list)
+  ;;          (cdar list))
+  ;;          (loop (cdr list)))))
+  (string-append
+   (opensmtpd-configuration-fieldname->string
+    record opensmtpd-configuration-bounce
+    (lambda (%bounce)
+      (if %bounce
+          (list-of-strings->string %bounce)
+          "")))
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-smtp
+                                              opensmtpd-smtp->string)
+   (opensmtpd-configuration-fieldname->string
+    record
+    opensmtpd-configuration-srs
+    opensmtpd-configuration-srs->string)
+   (opensmtpd-configuration-fieldname->string
+    record
+    opensmtpd-configuration-queue
+    opensmtpd-configuration-queue->string)
+   ;; write out the mta-max-deferred
+   (opensmtpd-configuration-fieldname->string
+    record opensmtpd-configuration-mta-max-deferred
+    (lambda (var)
+      (string-append "mta max-deferred "
+                     (number->string
+                      (opensmtpd-configuration-mta-max-deferred record))
+                     "\n")))
+   ;;write out all the tables
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-tables
+                                              opensmtpd-table->string)
+   ;; write out all the cas
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-cas
+                                              opensmtpd-ca->string)
+   ;; write out all the pkis
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-pkis
+                                              opensmtpd-pki->string)
+   ;; write all of the interface and socket records
+   (opensmtpd-configuration-fieldname->string
+    record
+    opensmtpd-configuration-interfaces
+    opensmtpd-interface->string)
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-socket
+                                              opensmtpd-socket->string)
+   ;; write all the actions
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-actions
+                                              opensmtpd-action->string)
+   ;; write all of the matches
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-matches
+                                              opensmtpd-match->string)))
+
+;; FIXME/TODO should I use format here srfi-28 ?
+;; web.scm nginx does a (format #f "string" "another string")
+;; this could be a list like
+;; (list
+;;   (file-append opensmtpd-dkimsign "/libexec/filter")
+;;   "-d gnucode.me -s /path/to/selector.cert")
+;; Then opensmtpd-configuration->mixed-text-file could be rewritten to be
+;; something like
+;; (mixed-text-file
+;;   (eval `(string-append (opensmtpd-configuration-fieldname->string ...))
+;;   (gnu services mail)))
+(define (opensmtpd-configuration->mixed-text-file record)
+  (apply mixed-text-file "smtpd.conf"
+         (flatten (list
+                   ;; write out the includes
+                   (opensmtpd-configuration-fieldname->string
+                    record
+                    opensmtpd-configuration-includes
+                    opensmtpd-configuration-includes->string)
+                   ;; TODO should I change the below line of code into these
+                   ;; two lines of code?
+                   ;;(opensmtpd-configuration-fieldname->string
+                   ;;  record get-opensmtpd-filters-and-filter-phases
+                   ;;  opensmtpd-filter-and-filter-phase->string)
+                   ;;(opensmtpd-configuration-fieldname->string
+                   ;;  record get-opensmtpd-filter-chains
+                   ;;  opensmtpd-filter-chain->string)
+                   ;; write out all the filters
+                   (opensmtpd-filters->list-of-strings-and-gexps
+                    (get-opensmtpd-filters record))
+                   (opensmtpd-configuration->string record)))))
+
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "
 listen on lo
@@ -1668,18 +4140,37 @@ (define %default-opensmtpd-config-file
 match from local for any action outbound
 "))
 
-(define opensmtpd-shepherd-service
-  (match-lambda
-    (($ <opensmtpd-configuration> package config-file)
-     (list (shepherd-service
+(define (opensmtpd-shepherd-service config)
+  (list (shepherd-service
             (provision '(smtpd))
             (requirement '(loopback))
             (documentation "Run the OpenSMTPD daemon.")
-            (start (let ((smtpd (file-append package "/sbin/smtpd")))
-                     #~(make-forkexec-constructor
-                        (list #$smtpd "-f" #$config-file)
-                        #:pid-file "/var/run/smtpd.pid")))
-            (stop #~(make-kill-destructor)))))))
+            (start
+             (let ((smtpd (file-append
+                           (opensmtpd-configuration-package config)
+                           "/sbin/smtpd")))
+               #~(make-forkexec-constructor
+                  (list #$smtpd "-f"
+                        (or
+                         #$(opensmtpd-configuration-config-file config)
+                         #$(opensmtpd-configuration->mixed-text-file config)))
+                  #:pid-file "/var/run/smtpd.pid")))
+            (stop #~(make-kill-destructor)))))
+
+;; TODO why does the below NOT work?
+;(define (opensmtpd-shepherd-service config)
+;  (match-lambda
+;    (($ <opensmtpd-configuration> package config-file)
+;     (list (shepherd-service
+;            (provision '(smtpd))
+;            (requirement '(loopback))
+;            (documentation "Run the OpenSMTPD daemon.")
+;            (start (let ((smtpd (file-append package "/sbin/smtpd")))
+;                     #~(make-forkexec-constructor
+;                        (list #$smtpd "-f" (or #$config-file
+;                                               #$(opensmtpd-configuration->mixed-text-file config)))
+;                        #:pid-file "/var/run/smtpd.pid")))
+;            (stop #~(make-kill-destructor)))))))
 
 (define %opensmtpd-accounts
   (list (user-group
@@ -1700,10 +4191,10 @@ (define %opensmtpd-accounts
          (home-directory "/var/empty")
          (shell (file-append shadow "/sbin/nologin")))))
 
-(define opensmtpd-activation
-  (match-lambda
-    (($ <opensmtpd-configuration> package config-file)
-     (let ((smtpd (file-append package "/sbin/smtpd")))
+(define (opensmtpd-activation config)
+  (let ((smtpd (file-append (opensmtpd-configuration-package config) "/sbin/smtpd"))
+        (config-file (opensmtpd-configuration-config-file config))
+        (configuration (opensmtpd-configuration->mixed-text-file config)))
        #~(begin
            (use-modules (guix build utils))
            ;; Create mbox and spool directories.
@@ -1711,7 +4202,36 @@ (define opensmtpd-activation
            (mkdir-p "/var/spool/smtpd")
            (chmod "/var/spool/smtpd" #o711)
            (mkdir-p "/var/spool/mail")
-           (chmod "/var/spool/mail" #o711))))))
+           (chmod "/var/spool/mail" #o711)
+           (display (string-append "checking syntax of "
+                                   (or
+                                    #$config-file
+                                    #$configuration)
+                                   "\n"))
+           (system* #$smtpd "-nf"
+                    (or
+                     #$config-file
+                     #$configuration)))))
+
+;; TODO why does this not work?
+;(define (opensmtpd-activation config)
+;  (match-lambda
+;    (($ <opensmtpd-configuration> package config-file)
+;     (let ((smtpd (file-append package "/sbin/smtpd"))
+;           (configuration (opensmtpd-configuration->mixed-text-file config)))
+;       #~(begin
+;           (use-modules (guix build utils))
+           ;; Create mbox and spool directories.
+;           (mkdir-p "/var/mail")
+;          (mkdir-p "/var/spool/smtpd")
+;         (chmod "/var/spool/smtpd" #o711)
+;        (mkdir-p "/var/spool/mail")
+;           (chmod "/var/spool/mail" #o711)
+;           (display (string-append "checking syntax of "
+;                                  (or
+;                                    #$config-file
+;                                    #$configuration)
+;                                   "\n")))))))
 
 (define %opensmtpd-pam-services
   (list (unix-pam-service "smtpd")))
diff --git a/gnu/tests/mail.scm b/gnu/tests/mail.scm
index f13751b72f..f9bd96402b 100644
--- a/gnu/tests/mail.scm
+++ b/gnu/tests/mail.scm
@@ -37,6 +37,7 @@ (define-module (gnu tests mail)
   #:use-module (guix gexp)
   #:use-module (guix store)
   #:use-module (ice-9 ftw)
+  #:use-module (srfi srfi-64)
   #:export (%test-opensmtpd
             %test-exim
             %test-dovecot
@@ -165,6 +166,718 @@ (define %test-opensmtpd
    (description "Send an email to a running OpenSMTPD server.")
    (value (run-opensmtpd-test))))
 
+;; trying to create a bad record, should result in an error.
+;; this function should not be able return, instead it should throw an error
+;(define (create-bad-record record)
+  ;; TODO why is this not working
+;  (with-output-to-port (%make-void-port "w")
+;    (lambda () (when record #f))))
+
+;; if this caller function is reached, then trying to create the bad record
+;; resulted in an error.  So return true.
+(define (return-true error arg)
+  #t)
+
+(define (return-false error arg)
+  #f)
+
+(define (test-good-record func)
+  (catch #t func return-false))
+
+(define (run-opensmtpd-record-sanitation-test)
+  ;;(with-output-to-port (%make-void-port "w")
+  ;;  (lambda ()
+  (test-begin "run-opensmtpd-record-sanitation-test")
+
+  (test-error "(interface (filters ...)) has two filters with the same name."
+              #t
+              (let ((dkimsign
+                     (opensmtpd-filter
+                      (name "dkimsign")
+                      (exec #t)
+                      (proc
+                       (list
+                        (file-append
+                         opensmtpd-filter-dkimsign
+                         "/libexec/opensmtpd/filter-dkimsign")
+                             " -d gnucode.me -s 2021-09-22 -c "
+                             "relaxed/relaxed -k "
+                             "rando string"
+                             "/etc/dkim/private.key "
+                             "user nobody group nogroup")))))
+                (opensmtpd-interface
+                  (interface "lo")
+                  (filters (list
+                            dkimsign
+                            dkimsign)))))
+
+  ;; duplicate filter names.  The filters are different, the fix
+  ;; is to change one filter's 'name' field.
+  (test-error "Test <interface> cannot have two filters with the same name."
+              #t
+              (opensmtpd-interface
+               (filters (list
+                         (opensmtpd-filter-phase
+                          (name "src")
+                          (phase "connect")
+                          (options
+                           (list
+                            (opensmtpd-option
+                             (option "fcrdns")
+                             (bool #f))))
+                          (decision "junk"))
+                         (opensmtpd-filter-phase
+                          (name "src")
+                          (phase "helo")
+                          (options
+                           (list
+                            (opensmtpd-option
+                             (option "rdns")
+                             (bool #f))))
+                          (decision "reject")
+                          (message "433 no rdns."))))))
+
+  (test-error "(filter (proc ...)) is a list of strings or gexps, NOT numbers."
+              #t
+              (opensmtpd-filter
+               (name "dkimsign")
+               (proc
+                (list
+                 (file-append opensmtpd-filter-dkimsign
+                              "/libexec/opensmtpd/filter-dkimsign")
+                 " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                 5
+                 "/etc/dkim/private.key "
+                 "user nobody group nogroup"))
+               (exec #t)))
+
+  (test-error "Test <filter-phase> fieldname 'phase' has an wrong phase name."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "wrongString")
+               (decision "bypass")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "auth"))))))
+
+  (test-error
+   "(filter-phase (decision \"reject\")) requires a 'message'."
+   #t
+   (opensmtpd-interface
+    (filters (list
+              (opensmtpd-filter-phase
+               (name "src")
+               (phase "connect")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "src")
+                  (data (opensmtpd-table
+                         (name "src-table")
+                         (data (list "cat" "hat")))))))
+               (decision "reject"))))))
+
+  (test-error (string-append
+               "Test <filter-phase> fieldname 'decision' "
+               "w/ value \"reject\" and \"disconnect\" requires a 'message'."
+               " The message must begin with 4xx or 5xx.")
+    #t
+    (opensmtpd-interface
+     (filters (list
+               (opensmtpd-filter-phase
+                (name "src")
+                (phase "connect")
+                (options
+                 (list
+                  (opensmtpd-option
+                   (option "src")
+                   (data (opensmtpd-table
+                          (name "src-table")
+                          (data (list "cat" "hat")))))))
+                (decision "reject")
+                (message "322 Bad data!"))))))
+
+  (test-error
+   "(filter-phase \"rewrite\") requires fieldname 'value' to have a number."
+   #t
+   (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "noFRDNS")
+       (phase "commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns")
+                       (bool #f))))
+       (decision "rewrite"))))))
+
+  (define option-string1/2 (list-ref (list "junk" "bypass")
+                                     (random 2)))
+  (test-error
+   (string-append "(filter-phase \"decision\" with values 'junk' or 'bypass',"
+                  " then fieldname 'message' and 'value' must be blank.")
+              #t
+              (opensmtpd-interface
+               (filters
+                (list
+                 (opensmtpd-filter-phase
+                  (name "noFRDNS")
+                  (phase "commit")
+                  (options (list (opensmtpd-option
+                                  (option "fcrdns")
+                                  )))
+                  (decision option-string1/2)
+                  (message "This is not a good email."))))))
+
+  (test-error "You cannot junk an email on phase commit."
+              #t
+    (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "junk-after-commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns"))))
+       (phase "commit")
+       (decision "junk"))))))
+
+  (define (good-interface1)
+    (opensmtpd-interface
+     (senders
+      (opensmtpd-table
+       (name "senders")
+       (data '(("joshua" . "joshua@dismail.de")))))
+     (masquerade #t)))
+
+  (test-assert "good interface" (test-good-record good-interface1))
+
+  (test-error "Test <filter-phase> has 2 duplicate options."
+              #t
+              (opensmtpd-filter-phase
+               (name "invalid-fcrdns")
+               (phase "connect")
+               (options
+                (list (opensmtpd-option
+                       (option "fcrdns"))
+                      (opensmtpd-option
+                       (option "fcrdns"))))
+               (decision "reject")
+               (message "422 No valid fcrdns.")))
+
+  (test-error "Test <filter-phase> option 'src' requires a table."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "helo")
+               (decision "bypass")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "src"))))))
+
+  (test-error "Test <filter-phase> option 'fcrdns' cannot have a table."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "helo")
+               (decision "bypass")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "fcrdns")
+                  (data (opensmtpd-table
+                         (name "table")
+                         (data (list "hello" "cat")))))))))
+
+  (test-error "Test <filter-phase> must have at least one option."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "helo")
+               (decision "bypass")))
+
+  (test-error
+   "(filter-phase (options ...)) must be a list of <opensmtpd-option>s."
+              #t
+              (opensmtpd-filter-phase
+               (name "rdns")
+               (decision "junk")
+               (phase "helo")
+               (options
+                (list 5))))
+
+  (test-error "Test (decision \"junks\") is invalid."
+              #t
+              (opensmtpd-filter-phase
+               (name "this")
+               (options (list
+                         (opensmtpd-option
+                          (option "auth"))))
+               (phase "helo")
+               (decision "junks")))
+
+  (test-error
+   (string-append
+    "(local-delivery (virtual ...) must be an <opensmtp-table> "
+    "whose 'data' is an alist.")
+              #t
+              (opensmtpd-local-delivery
+               (name "receive")
+               (method (opensmtpd-maildir
+                        (pathname "/home/%{rcpt.user}/Maildir")))
+               (virtual (opensmtpd-table
+                         (name "virt")
+                         (data (list "jbranso@dismail.de"))))))
+
+  (test-error "(opensmtpd-match (options ...)) should not be quoted."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options
+                '((opensmtpd-option
+                   (option "for any"))))))
+
+  (test-error "Test <opensmtpd-match> has duplicate 'for' options."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "for any"))
+                         (opensmtpd-option
+                          (option "for local"))))))
+
+  (test-error "Test <opensmtpd-match> has duplicate 'from' options."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "from any"))
+                         (opensmtpd-option
+                          (option "from auth"))))))
+
+  (define option-string1
+    (list-ref (list "helo" "rcpt-to" "mail-from")
+              (random 3)))
+  ;; rcpt-to, mail-from, and helo must have a data field.
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string1
+                             "\")) must also define fieldname 'data'.")
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option option-string1))))))
+  (define option-string2
+    (list-ref (list "for local" "for any" "from any"
+                    "from local" "from socket" "tls")
+              (random 6)))
+  ;; "for local" "for any" "from any" "from local" "from socket" "tls"
+  ;; cannot have data or regex defined
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string2
+                             "\")) cannot have fieldname 'data' defined.")
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option option-string2)
+                          (regex #t))))))
+
+  (test-error "(opensmtpd-match (action ...)) needs to be defined."
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (option "from auth"))))))
+
+  (test-error "(opensmtpd-match (options ...)) has duplicate 'helo's."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "helo")
+                          (bool #f))
+                         (opensmtpd-option
+                          (option "helo"))))))
+
+  (test-error "(opensmtpd-match (options ...)) has duplicate 'mail-from's."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "mail-from")
+                          (data "hello"))
+                         (opensmtpd-option
+                          (option "mail-from")
+                          (data "world"))))))
+
+  (test-error
+   "(opensmtpd-match (options ...)) has an invalid option name: fcrdns."
+   #t
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "fcrdns"))))
+    (action (opensmtpd-relay
+             (name "relay")))))
+
+  (test-error
+   "(opensmtpd-match (options ...)) has an invalid option name: rdns."
+   #t
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "rdns"))))
+    (action (opensmtpd-relay
+             (name "relay")))))
+
+  (test-error
+   (string-append
+    "(opensmtpd-match (options ...)) option-name 'tag' must "
+    "also have 'data' be a string.")
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (option "tag"))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+  (define option-string3
+    (list-ref (list "for domain" "for rcpt-to"
+                    "from mail-from" "from src")
+              (random 4)))
+  ;; the options in this list:
+  ;; (list "for domain" "for rcpt-to" "from mail-from" "from src")
+  ;; must have a data field.
+  (test-error
+   (string-append "Test (opensmtpd-option (option \""
+                  option-string3 "\"))"
+                  " must define fieldname 'data'.")
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (option option-string3))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+  (define option-string4
+    (list-ref (list "for local" "for any" "from any"
+                    "from local" "from socket" "tls")
+              (random 6)))
+  ;; the options in this list cannot have a data or regex field defined.
+  ;; (list "for local" "for any" "from any" "from local" "from socket" "tls")
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string4 "\"))"
+                             " cannot define fieldname 'data'.")
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (regex #t)
+                          (option option-string4))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+
+  (define option-string5
+    (list-ref (list "for domain" "for rcpt-to"
+                    "from mail-from" "from src")
+              (random 4)))
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string5 "\"))"
+                             " must define fieldname 'data' as a string or "
+                             "an <opensmtpd-table>, whose 'data' \n"
+                             "is a list of strings.")
+              #t
+              (opensmtpd-match
+               (options
+                (list (opensmtpd-option
+                       (option option-string5)
+                       (data (opensmtpd-table
+                              (name "src-table")
+                              (data '(("127.0.0.1" . "374.394.405.23"))))))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+  ;; match must have at least one option.
+  (test-error
+   "(opensmtpd-match (options ...)) must have at least one <opensmtpd-option>."
+   #t
+   (opensmtpd-match
+    (action
+     (opensmtpd-local-delivery
+      (name "mail")))))
+
+  ;; you cannot have strings of length 0.
+  (test-error
+   (string-append
+    "(opensmtpd-table (name \"table\") (data '((\"james\" . \"\")))) "
+    "has an empty string.")
+   #t
+   (opensmtpd-table
+    (name "mytable")
+    (data '(("hello" . "")))))
+
+  (define good-match1
+    (opensmtpd-match
+     (action (opensmtpd-relay
+              (name "relay")))
+     (options (list (opensmtpd-option
+                     (option "for any"))
+                    (opensmtpd-option
+                     (option "from any"))
+                    (opensmtpd-option
+                     (option "auth"))))))
+
+  (test-assert "good match" (test-good-record good-match1))
+  ;;(test-assert "Test <opensmtpd-match> is valid.")
+
+  ;; I used to have some code that assumed if you have
+  ;; an "<interface>" and an "<socket>" using the same filter, then that
+  ;; was a misconfiguration.  It's not.
+  (define (good-opensmtpd-configuration1)
+    (let ([interface "lo"]
+          [filter-dkimsign
+           (opensmtpd-filter
+            (name "dkimsign")
+            (exec #t)
+            (proc (list (file-append opensmtpd-filter-dkimsign
+                                     "/libexec/opensmtpd/filter-dkimsign")
+                        " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                        "/etc/dkim/private.key "
+                        "user nobody group nogroup")))])
+      (opensmtpd-configuration
+       (interfaces
+        (list
+         ;; send out emails and be sure to dkimsign them.
+         (opensmtpd-interface
+          (interface interface)
+          (filters (list filter-dkimsign)))))
+       (socket
+        (opensmtpd-socket
+         (filters (list filter-dkimsign))))
+       (matches (list
+                 (opensmtpd-match
+                  (action (opensmtpd-relay
+                           (name "relay")))
+                  (options (list (opensmtpd-option
+                                  (option "for any"))
+                                 (opensmtpd-option
+                                  (option "from any"))
+                                 (opensmtpd-option
+                                  (option "auth"))))))))))
+
+  (test-assert
+      (string-append "opensmtpd-configuration may use the same dkimsign "
+                     "filter on <opensmtpd-socket> and <opensmtpd-interface>.")
+    (test-good-record good-opensmtpd-configuration1))
+
+  ;; this is just the largest configuration that I can test.
+  (define (good-opensmtpd-configuration2)
+    (let ([interface "lo"]
+          [creds-table
+           (opensmtpd-table
+            (name "creds")
+            (data
+             (list
+              (cons "joshua"
+                    "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))))]
+          [receive-action
+           (opensmtpd-local-delivery
+                           (name "receive")
+                           (method (opensmtpd-maildir
+                                    (pathname "/home/%{rcpt.user}/Maildir")
+                                    (junk #t)))
+                           (alias (opensmtpd-table
+                                   (name "aliases")
+                                   (data '(("joshua@gnucode.me" . "joshua")))))
+                           (virtual (opensmtpd-table
+                                     (name "virt")
+                                     (data '(("josh"
+                                              . "jbranso@dismail.de"))))))]
+          ;; as of 7-24-22 this proc fieldname does not actually work, but
+          ;; is proper syntax.
+          [filter-dkimsign (opensmtpd-filter
+                            (name "dkimsign")
+                            (exec #t)
+                            (proc (list
+                                   (file-append
+                                    opensmtpd-filter-dkimsign
+                                    "/libexec/opensmtpd/filter-dkimsign")
+                                   " -d gnucode.me -s 2021-09-22 -c "
+                                   "relaxed/relaxed -k "
+                                   "/etc/dkim/private.key "
+                                   "user nobody group nogroup")))]
+          [filter-invalid-fcrdns (opensmtpd-filter-phase
+                                  (name "invalid-fcrdns")
+                                  (phase "connect")
+                                  (options
+                                   (list (opensmtpd-option
+                                          (option "fcrdns")
+                                          (bool #f))))
+                                  (decision "reject")
+                                  (message "422 No valid fcrdns."))]
+          [filter-invalid-rdns (opensmtpd-filter-phase
+                                (name "invalid-rdns")
+                                (phase "connect")
+                                (options
+                                 (list (opensmtpd-option
+                                        (option "rdns")
+                                        (bool #f))))
+                                (decision "junk"))]
+          [smtp.gnucode.me (opensmtpd-pki
+                            (domain "smtp.gnucode.me")
+                            (cert "guix.scm")
+                            (key "guix.scm"))])
+      (opensmtpd-configuration
+       (mta-max-deferred 50)
+       (queue
+        (opensmtpd-queue
+         (compression #t)))
+       (smtp
+        (opensmtpd-smtp
+         (max-message-size "10M")))
+       (srs
+        (opensmtpd-srs
+         (ttl-delay "5d")))
+       (interfaces
+        (list
+         (opensmtpd-interface
+          (interface interface)
+          (port 25)
+          (secure-connection "tls")
+          (filters (list filter-invalid-fcrdns
+                         filter-invalid-rdns))
+          (pki smtp.gnucode.me))
+         ;; this lets local users logged into the system via ssh send email
+         ;; be sure to dkimsign them.
+         (opensmtpd-interface
+          (interface interface)
+          (port 465)
+          (secure-connection "smtps")
+          (pki smtp.gnucode.me)
+          (auth creds-table)
+          (filters (list filter-dkimsign)))
+         ;; if you uncomment this next line, then you get issues.
+         ;;(opensmtpd-socket
+         ;; (filters (list filter-dkimsign)))
+         ;; send out emails and be sure to dkimsign them.
+         (opensmtpd-interface
+          (interface interface)
+          (port 587)
+          (secure-connection "tls-require")
+          (pki smtp.gnucode.me)
+          (auth creds-table)
+          (filters (list filter-dkimsign)))))
+       (socket
+        (opensmtpd-socket
+         (filters (list filter-dkimsign))
+         (tag "socket")))
+       (matches (list
+                 (opensmtpd-match
+                  (action (opensmtpd-relay
+                           (name "relay")))
+                  (options (list (opensmtpd-option
+                                  (option "for any"))
+                                 (opensmtpd-option
+                                  (option "from any"))
+                                 (opensmtpd-option
+                                  (option "auth")))))
+                 (opensmtpd-match
+                  (action receive-action)
+                  (options (list (opensmtpd-option
+                                  (option "from any"))
+                                 (opensmtpd-option
+                                  (option "for domain")
+                                  (data (opensmtpd-table
+                                         (name "domain-table")
+                                         (data (list "gnucode.me"
+                                                     "gnu-hurd.com"))))))))
+                 (opensmtpd-match
+                  (action receive-action)
+                  (options (list (opensmtpd-option
+                                  (option "for local"))))))))))
+
+  (test-assert "Test my largish example <opensmtpd-configuration>."
+    (test-good-record good-opensmtpd-configuration2))
+
+  ;; the matches have two actions with the same name,
+  ;; but are different actions.
+  (test-error
+   (string-append "Test <opensmtpd-configuration> fieldname 'matches' has "
+                  "two actions with the same name, but the actions are "
+                  "different.")
+   #t
+   (opensmtpd-configuration
+    (matches
+     (list (opensmtpd-match
+            (options
+             (list
+              (opensmtpd-option
+               (option "auth"))))
+            (action
+             (opensmtpd-local-delivery
+              (name "my-local-delivery")
+              (ttl "50m"))))
+           (opensmtpd-match
+            (options
+             (list
+              (opensmtpd-option
+               (option "auth"))))
+            (action
+             (opensmtpd-local-delivery
+              (name "my-local-delivery")
+              (ttl "50h"))))))))
+
+  ;; you can only have 1 opensmtpd-socket.
+  (test-error
+   (string-append
+    "(opensmtpd-configuration> (listen-on ...)) may only have "
+    "one <opensmtpd-socket>.")
+   #t
+   (let ([interface "lo"])
+     (opensmtpd-configuration
+      (socket
+       (list
+        (opensmtpd-socket)
+        (opensmtpd-socket)))
+      (matches (list
+                (opensmtpd-match
+                 (options
+                  (list
+                   (opensmtpd-option
+                    (option "auth"))))
+                 (action (opensmtpd-relay
+                          (name "relay")))))))))
+
+  (test-end "run-opensmtpd-record-sanitation-test"))
+
+(define %test-opensmtpd-record-sanitation
+  (system-test
+   (name "opensmtpdRecordSanitation")
+   (description
+    (string-append "<opensmtpd> has numerous sanity checks.\n"
+                   "This checks that invalid configurations, return an\n"
+                   "appropriate error.\n"))
+   (value (run-opensmtpd-record-sanitation-test))))
+
 
 (define %exim-os
   (simple-operating-system
-- 
2.38.1





^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH opensmtpd-records v4 fixing charset=y error] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
                   ` (3 preceding siblings ...)
  2022-10-24 17:30 ` [bug#56046] [Patch master v2] services (opensmtpd): " Joshua Branson via Guix-patches via
@ 2022-12-23 16:39 ` Joshua Branson via Guix-patches via
  2023-06-15 16:06 ` [bug#56046] [PATCH] services: mail: " Vivien Kraus via Guix-patches via
  5 siblings, 0 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-12-23 16:39 UTC (permalink / raw)
  To: 56046; +Cc: Joshua Branson

Whoops the last sent patch had some charset=y errors.  Hopefully this is better.

This is V3 of my opensmtp records configuration. Hopefully soon, I will have
this WIP service is guixrus, so more people can easily play with it.

https://git.sr.ht/~whereiseveryone/guixrus

BUT the new milestone is this, I am now actually able to use opensmtpd on my
gnucode.me account! So that is pretty awesome!

Here is a link to my server config:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/linode-locke-lamora-current-config.scm

The best place to find documentation for this service is here:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd-records-documentation.txt


Openmstpd-configuration may only be configured by a config-file that
uses the smtpd.conf syntax.  This patch, enables one to configure
opensmtpd by using record types.

* gnu/services/mail.scm:
(opensmtpd-table,
opensmtpd-ca,
opensmtpd-pki,
opensmtpd-action-local-delivery,
opensmtpd-maildir,
opensmtpd-mda,
opensmtpd-lmtp,
opensmtpd-relay,
opensmtpd-option,
opensmtpd-filter-phase,
opensmtpd-filter,
opensmtpd-interface,
opensmtpd-socket,
opensmtpd-match,
opensmtpd-smtp,
opensmtpd-srs,
opensmtpd-queue, and
opensmtpd-configuration): New records.

(false?, is-value-right-type, add-comma-or-string,
list-of-procedures->string, string-in-list?, my-sanitize,
opensmtpd-filter-chain?, throw-error-duplicate-option,
sanitize-list-of-options-for-match, sanitize-filters,
list-has-duplicates-or-non-filters?,
filter-phase-has-message-and-value?,
filter-phase-decision-lacks-proper-message?,
filter-phase-lacks-proper-value?,
filter-phase-has-incorrect-junk-or-bypass?,
filter-phase-junks-after-commit?,
list-of-unique-filter-or-filter-phase?, throw-error,
contains-duplicate?, list-of-type?, list-of-strings?,
list-of-unique-opensmtpd-option?,
list-of-opensmtpd-ca?,
list-of-opensmtpd-pki?,
list-of-opensmtpd-listen-on?,
list-of-unique-opensmtpd-match?, list-of-strings->string,
assoc-list? assoc-list, variable->string,
tables-data-are-assoc-list?,
tables-data-are-a-list-of-strings?,
table-data-are-a-nested-list-of-strings?,
assoc-list->string,
opensmtpd-table->string,
opensmtpd-listen-on->string,
opensmtpd-listen-on-socket->string,
opensmtpd-action-relay->string,
opensmtpd-lmtp->string,
opensmtpd-mda->string,
opensmtpd-maildir->string,
opensmtpd-action-local-delivery->string,
opensmtpd-action->string, opensmtpd-option->string,
opensmtpd-match->string,
opensmtpd-ca->string, opensmtpd-pki->string,
generate-filter-chain-name, opensmtpd-filter-chain->string,
opensmtpd-filter-phase->string, opensmtpd-filters->string,
opensmtpd-listen->string,
opensmtpd-srs->string,
opensmtpd-smtp->string,
opensmtpd-queue->string, get-opensmtpd-actions,
get-opensmtpd-pkis, get-opensmtpd-filters, flatten,
get-opensmtpd-tables, opensmtpd-fieldname->string,
list-of-records->string, opensmtpd->mixed-text-file): New
procedures.

* gnu/tests/mail.scm : new tests for various opensmtpd records.

* doc/guix.texi (OpenSMTPD Service): Added documentation for the
new records for opensmtpd.
---
 doc/guix.texi         | 1065 ++++++++++++++++-
 gnu/services/mail.scm | 2560 ++++++++++++++++++++++++++++++++++++++++-
 gnu/tests/mail.scm    |  713 ++++++++++++
 3 files changed, 4310 insertions(+), 28 deletions(-)

diff --git a/doc/guix.texi b/doc/guix.texi
index 535c8cdfc3..879a2ad233 100644
--- a/doc/guix.texi
+++ b/doc/guix.texi
@@ -25407,16 +25407,66 @@ could instantiate a dovecot service like this:
 @end lisp
 
 @subsubheading OpenSMTPD Service
+@cindex opensmtpd
 
 @deffn {Scheme Variable} opensmtpd-service-type
-This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
-service, whose value should be an @code{opensmtpd-configuration} object
-as in this example:
+OpenSMTPD is an easy-to-use mail transfer agent (MTA).  OpenSMTPD
+@strong{listens} for incoming mail and @strong{matches} the mail to
+@strong{actions}. The following records represent those stages:
 
-@lisp
-(service opensmtpd-service-type
-         (opensmtpd-configuration
-           (config-file (local-file "./my-smtpd.conf"))))
+@multitable {aaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @strong{listens}
+@tab @code{<opensmtpd-interface>}
+@item
+@tab @code{<opensmtpd-socket>}
+@item
+@tab
+@item @strong{matches}
+@tab @code{<opensmtpd-match>}
+@item
+@tab
+@item @strong{actions}
+@tab @code{<opensmtpd-local-delivery>}
+@item
+@tab @code{<opensmtpd-relay>}
+@end multitable
+
+Additionally, each @code{<opensmtpd-interface>} and
+@code{<opensmtpd-socket>} may use a list of @code{<opensmtpd-filter>},
+and/or @code{<opensmtpd-filter-phase>} records to filter
+email/spam. Also numerous records' fieldnames use
+@code{<opensmtpd-table>} records to hold lists or key value pairs of
+data.  Be sure to read the @code{<opensmtpd-table>} section to learn the
+differance between a @code{mapping table} and a @code{list table}.
+
+Finally, both @code{<opensmtpd-match>} and
+@code{<opensmtpd-filter-phase>} use @code{<opensmtpd-option>} to
+configure various options.
+
+A simple example opensmtpd configuration is below:
+
+@lisp
+(let ((smtp.gnu.org (opensmtpd-pki
+                        (domain "smtp.gnu.org")
+                        (cert "file.cert")
+                        (key "file.key"))))
+  (service opensmtpd-service-type
+           (opensmtpd-configuration
+            (interfaces (list
+                         (opensmtpd-interface
+                          (pki smtp.gnu.org))
+                         (opensmtpd-interface
+                          (pki smtp.gnu.org)
+                          (secure-connection "smtps"))))
+            (matches (list
+                      (opensmtpd-match
+                       (action
+                        (opensmtpd-local-delivery
+                         (name "local-delivery"))))
+                      (opensmtpd-match
+                       (action
+                        (opensmtpd-relay
+                         (name "relay")))))))))
 @end lisp
 @end deffn
 
@@ -25425,7 +25475,7 @@ Data type representing the configuration of opensmtpd.
 
 @table @asis
 @item @code{package} (default: @var{opensmtpd})
-Package object of the OpenSMTPD SMTP server.
+Package object of the OpenSMTPD server.
 
 @item @code{config-file} (default: @code{%default-opensmtpd-config-file})
 File-like object of the OpenSMTPD configuration file to use.  By default
@@ -25433,14 +25483,1013 @@ it listens on the loopback network interface, and allows for mail from
 users and daemons on the local machine, as well as permitting email to
 remote servers.  Run @command{man smtpd.conf} for more information.
 
+@item @code{bounce} (default: @code{(list "4h")})
+@code{bounce} is a list of strings, which send warning messages to the
+envelope sender when temporary delivery failures cause a message to
+remain in the queue for longer than a specified delay. Each delay option
+is a string parameter beginning with a positive decimal integer and a
+unit, which can be 's', 'm', 'h', or 'd'. At most four delay parameters
+can be specified.
+
+@item @code{interfaces} default:
+@lisp
+(list
+  (opensmtpd-interface
+    (interface "lo")
+    (port 25)))
+@end lisp
+@code{interfaces} is a list of @code{<opensmtpd-interface>} records.
+This list details what interfaces and ports OpenSMTPD listens on as well as
+other options.
+
+@item @code{socket} (default: @code{(opensmtpd-socket)})
+Listens for incoming connections on the Unix domain socket.
+
+@item @code{includes} (default: @code{#f})
+@code{includes} is a list of string filenames. Each filename's contents is
+additional configuration that is inserted into the top of the configuration
+file.  Run @code{man smtpd.conf} for more information.
+
+@item @code{matches} default:
+@lisp
+(list (opensmtpd-match
+       (action (opensmtpd-local-delivery
+                (name "local")
+                (method "mbox")
+                (options
+                 (list
+                  (opensmtpd-option
+                   (option "for local")))))))
+      (opensmtpd-match
+       (action (opensmtpd-relay
+                (name "outbound")))
+       (options
+        (list
+         (opensmtpd-option
+          (option "from local"))
+         (opensmtpd-option
+          (option "for any"))))))
+@end lisp
+@code{matches} is a list of @code{<opensmtpd-match>} records, which
+matches incoming mail and sends it to a correspending action. The match
+records are evaluated sequentially, with the first match winning.
+Therefore @emph{the order that you arrange your matches is important}.
+It's a good idea to put specific matches first and an all emcompassing
+match (like @code{(option "for any")}) @strong{last}. If an incoming
+mail does not match any match records, then it is rejected.
+
+@item @code{mta-max-deferred} (default: @code{100})
+When delivery to a given host is suspended due to temporary failures, cache
+at most number envelopes for that host such that they can be delivered as
+soon as another delivery succeeds to that host. The default is 100.
+
+@item @code{queue} (default: @code{#f})
+@code{queue} expects an @code{<opensmtpd-queue>} record. With it, one may
+compress and encrypt queue-ed emails as well as set the default expiration
+time for temporarily undeliverable messages.
+
+@item @code{smtp} (default: @code{#f})
+@code{smtp} expects an @code{<opensmtpd-smtp>} record, which lets one
+specifiy how large email may be along with other settings.
+
+@item @code{srs} (default: @code{#f})
+@code{srs} expects an @code{<opensmtpd-srs>} record, which lets one set
+up SRS, the Sender Rewritting Scheme.
+
 @item @code{setgid-commands?} (default: @code{#t})
 Make the following commands setgid to @code{smtpq} so they can be
 executed: @command{smtpctl}, @command{sendmail}, @command{send-mail},
 @command{makemap}, @command{mailq}, and @command{newaliases}.
 @xref{Setuid Programs}, for more information on setgid programs.
+
 @end table
 @end deftp
 
+@itemize
+@item Data Type: opensmtpd-interface
+Data type representing the configuration of an
+@code{<opensmtpd-interface>}. It listens on the fieldname
+@code{interface} for incoming connections, using the same syntax as
+@code{ifconfig}. The interface parameter may also be an string interface
+group, an string IP address, or a string domain name. Listening can
+optionally be restricted to a specific address via the fieldname
+@code{family}, which can be either @code{"inet4"} or @code{"inet6"}.
+
+@itemize
+@item @code{interface} (default: @code{"lo"})
+
+The string interface to listen for incoming connections.  This string
+may be an interface group, an IP address, or a domain name. These
+interfaces can usually be found by the command @code{ip link}.
+
+@item @code{family} (default: @code{#f})
+
+Only listen on a specific address family.  Valid strings are
+@code{"inet4"} or @code{"inet6"}, which will only listen on IPv4 or IPv6
+respectfully.  If @code{(family #f)}, then opensmtpd will listen on both
+IPv4 and IPv6.
+
+@item @code{auth} (default: @code{#f})
+Support SMTPAUTH: clients may only start SMTP transactions after
+successful authentication. If @code{auth} is @code{#t}, then users are
+authenticated against their own normal login credentials. Alternatively
+@code{auth} may be a @code{mapping table} that maps usernames to
+encrypted passwords.  The password can be encrypted via the
+@code{smtpctl} @code{encrypt} subcommand.
+
+@item @code{auth-optional} (default: @code{#f})
+Support SMTPAUTH optionally: clients need not authenticate, but may do
+so.  This allows the @code{<opensmtpd-interface>} to both accept
+incoming mail from untrusted senders and permit outgoing mail from
+authenticated users. It can be used in situations where it is not
+possible to listen on a separate port (usually the submission port, 587)
+for users to authenticate.  This option also accepts a @code{mapping
+table} that maps usernames to encrypted passwords.
+
+@item @code{filters} (default: @code{#f})
+A list of one or many @code{<opensmtpd-filter>} or
+@code{<opensmtpd-filter-phase>} records. The filters are applied
+sequentially. These records listen and filter on connections handled by this
+listener.
+
+@item @code{hostname} (default: @code{#f})
+Change the default server name in the greeting banner instead of the
+default one.
+
+@item @code{hostnames} (default: @code{#f})
+Override the server name for specific addresses. Use a @code{mapping
+table} that maps string IP addresses to string hostnames. If the address
+on which the connection arrives appears in the mapping, the associated
+hostname is used.
+
+@item @code{mask-src} (default: @code{#f})
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{disable-dsn} (default: @code{#f})
+When @code{#t}, then disable the DSN (Delivery Status Notification) extension.
+
+@item @code{pki} (default: @code{#f})
+For secure connections, use an @code{<opensmtpd-pki>} record to prove a
+mail server's identity.
+
+@item @code{port} (default: @code{25})
+Listen on the integer port instead of the default port of 25.
+
+@item @code{proxy-v2} (default: @code{#f})
+If @code{#t}, then support the PROXYv2 protocol, rewriting appropriately source
+address received from proxy.
+
+@item @code{received-auth} (default: @code{#f})
+If @code{#t}, then in “Received” headers, report whether the session was
+authenticated and by which local user.
+
+@item @code{senders} (default: @code{#f})
+Look up the authenticated user in the supplied @code{mapping table} to
+find the email addresses that user is allowed to submit mail as.
+
+@item @code{masquerade} (default: @code{#f})
+@code{masquerade}, is used in conjunction with @code{senders}.  If
+@code{#t}, then the From header is rewritten to match the sender
+provided in the SMTP session.  If @code{senders} is @code{#false}, then
+@code{masquerade} cannot be @code{#t}.
+
+@item @code{secure-connection} (default: @code{#f})
+This is a string of one of these options:
+
+@multitable {aaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"smtps"}
+@tab Support SMTPS, by default on port 465.
+@item @code{"tls"}
+@tab Support STARTTLS, by default on port 25.
+@item @code{"tls-require"}
+@tab Like @code{"tls"}, but force clients to
+@item
+@tab establish a secure connection before being
+@item
+@tab allowed to start an SMTP transaction.
+@item @code{"tls-require-verify"}
+@tab Like @code{"tls-require"}, but clients must
+@item
+@tab also provide a valid certificate
+@item
+@tab to establish an SMTP session.
+@end multitable
+
+@item @code{tag} (default: @code{#f})
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-socket
+Data type representing the configuration of an
+@code{<opensmtpd-socket>}. Listen for incoming SMTP connections on the
+Unix domain socket @samp{/var/run/smtpd.sock}. This is done by default,
+even if the record is absent.
+
+@itemize
+@item @code{filters} (default: @code{#f})
+A list of one or many @code{<opensmtpd-filter>} or
+@code{<opensmtpd-filter-phase>} records. These filter incoming
+connections handled by this listener.
+
+@item @code{mask-src} (default: @code{#f})
+If @code{#t}, then omit the from part when prepending “Received” headers.
+
+@item @code{tag} (default: @code{#f})
+Clients connecting to the listener are tagged with the given string tag.
+@end itemize
+
+@item Data Type: opensmtpd-match
+@cindex opensmtpd-match
+This data type represents the configuration of an
+@code{<opensmtpd-match>} record.
+
+If at least one mail envelope matches the options of one match record,
+receive the incoming message, put a copy into each matching envelope,
+and atomically save the envelopes to the mail spool for later processing
+by the respective @code{<opensmtpd-action>} found in fieldname
+@code{action}.  Here is an example @code{opensmtpd-match}
+record.
+
+@lisp
+(opensmtpd-match
+ (action (opensmtpd-local-delivery
+          (name "receive")
+          (method (opensmtpd-maildir
+                   (pathname "/home/%@{rcpt.user@}/Maildir")
+                   (junk #t)))
+          (virtual (opensmtpd-table
+                    (name "virt")
+                    (data '(("carmen" . "carmen@@gnu.org")))))))
+ (options (list (opensmtpd-option
+                 (option "from any"))
+                (opensmtpd-option
+                 (option "for domain")
+                 (data (opensmtpd-table
+                        (name "domain-table")
+                        (data (list "gnu.org" "fsf.org"))))))))
+@end lisp
+
+@itemize
+@item @code{action} (default: @code{#f})
+
+If mail matches this match configuration, then do this action. Valid values
+include @code{<opensmtpd-local-delivery>} or
+@code{<opensmtpd-relay>}.
+
+@item @code{options} (default: @code{#f})
+The fieldname @code{option} is a list of unique
+@code{<opensmtpd-option>} records.
+
+There are some mutually exclusive options: there can be only one ``for''
+and only one ``from'' option.
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@headitem for
+@tab from
+@item only use one of the following:
+@tab only use one of the following:
+@item @code{"for any"}
+@tab @code{"from any"}
+@item @code{"for local"}
+@tab @code{"from auth"}
+@item @code{"for domain"}
+@tab @code{"from local"}
+@item @code{"for rcpt-to"}
+@tab @code{"from mail-from"}
+@item
+@tab @code{"from socket"}
+@item
+@tab @code{"from src"}
+@end multitable
+
+Additionally, some options require additional data via
+@code{<opensmtpd-option>}'s fieldname @code{data}.  The following list
+will explain the below syntax.
+
+@itemize
+@item @code{"for any"}
+This option only requires fieldname @code{option} to have the string
+@code{"for any"}:
+
+@lisp
+      (opensmtpd-option
+       (option "for any"))
+@end lisp
+
+@item @code{"tag"} _tag_
+This option only requires fieldname @code{option} to have the string
+@code{"tag"} with a string in fieldname @code{data}:
+
+@lisp
+      (opensmtpd-option
+       (option "tag")
+       (data "this-tag"))
+@end lisp
+
+@item @code{"for rcpt"} _domain_ | <list table>
+This option requires fieldname @code{data} to have a string domain or
+@code{list table}:
+
+@lisp
+      (opensmtpd-option
+       (option "for rcpt")
+       (data "gnu.org"))
+@end lisp
+
+OR
+
+@lisp
+      (opensmtpd-option
+       (option "for rcpt")
+       (data (list "gnu.org" "fsf.org")))
+@end lisp
+@end itemize
+
+The following matching options are supported and can all be negated (via not
+#t). The options that support a table (anything surrounded with '<' and '>'
+eg: <table>), also support specifying regex via (regex #t).
+
+@itemize
+@item @code{"for any"}
+Specify that session may address any destination.
+
+@item @code{"for local"}
+Specify that session may address any local domain.  This is the default,
+and may be omitted.
+
+@item @code{"for domain"} _domain_ | <domain>
+Specify that session may address the string _domain_ or
+@code{list table} <domain>.
+
+@item @code{"for rcpt-to"} _recipient_ | <recipient>
+Specify that session may address the string _recipient_ or list table
+<recipient>.
+
+@item @code{"from any"}
+Specify that session may originate from any source.
+
+@item @code{"from auth"}
+Specify that session may originate from any authenticated user, no matter
+the source IP address.
+
+@item @code{"from auth"} _user_ | <user>
+Specify that the session may originate from authenticated _user_ or
+@code{list table} <user>, no matter the source IP address.
+
+@item @code{"from local"}
+Specify that session may only originate from a local IP address, or from
+the local enqueuer.  This is the default, and may be omitted.
+
+@item @code{"from mail-from"} _sender_ | <sender>
+Specify that session may originate from _sender_ or @code{list table}
+<sender>, no matter the source IP address.
+
+@item @code{"from rdns"}
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS@.
+
+@item @samp{"from rdns"} _hostname_ | <hostname>
+Specify that session may only originate from an IP address that resolves
+to a reverse DNS matching string _hostname_ or @code{list table}
+<hostname>.
+
+@item @samp{"from socket"}
+Specify that session may only originate from the local enqueuer.
+
+@item @code{"from src"} _address_ | <address>
+Specify that session may only originate from string _address_ or
+@code{list table} <address> which can be a specific address or a subnet
+expressed in CIDR-notation.
+
+@item @code{"auth"}
+Matches transactions which have been authenticated.
+
+@item @code{"auth"} _username_ | <username>
+Matches transactions which have been authenticated for string _user_ or
+@code{list table} <username>.
+
+@item @code{"helo"} _helo-name_ | <helo-name>
+Specify that session's HELO / EHLO should match the string _helo-name_
+or @code{list table} <helo-name>.
+
+@item @code{"mail-from"} _sender_ | <sender>
+Specify that transactions's MAIL FROM should match the string _sender_
+or @code{list table} <sender>.
+
+@item @code{"rcpt-to"} _recipient_ | <recipient>
+Specify that transaction's RCPT TO should match the string _recipient_
+or @code{list table} <recipient>.
+
+@item @code{"tag"} _tag_
+Matches transactions tagged with the given tag.
+
+@item @code{"tls"}
+Specify that transaction should take place in a TLS channel.
+@end itemize
+
+@end itemize
+
+@item Data Type: opensmtpd-local-delivery
+This data type represents the configuration of an
+@code{<opensmtpd-local-delivery>} record.
+
+@itemize
+@item @code{name} (default: @code{#f})
+@code{name} is the string name of the relay action.
+
+@item @code{method} (default: @code{"mbox"})
+The email delivery option.  Valid options are:
+
+@itemize
+@item @code{"mbox"}
+Deliver the message to the user's mbox with mail.local(8).
+
+@item @code{"expand-only"}
+Only accept the message if a delivery method was specified in an aliases
+or .forward file.
+
+@item @code{"forward-only"}
+Only accept the message if the recipient results in a remote address after
+the processing of aliases or forward file.
+
+@item @code{<opensmtpd-lmtp>}
+Deliver the message to an LMTP server at @code{<opensmtpd-lmtp>}'s
+fieldname @code{destination}. The location may be expressed as string
+host:port or as a UNIX socket. Optionally, @code{<opensmtpd-lmtp>}'s
+fieldname @code{rcpt-to} might be specified to use the recipient email
+address (after expansion) instead of the local user in the LMTP session
+as RCPT TO.
+
+@item @code{<opensmtpd-maildir>}
+Deliver the message to the maildir in
+@code{<opensmtpd-maildir>}'s fieldname @code{pathname} if specified,
+or by default to @code{"~/Maildir"}.
+
+The pathname may contain format specifiers that are expanded before use
+(see the below section about Format Specifiers).
+
+If @code{<opensmtpd-maildir>}'s record fieldname @code{junk} is @code{#t},
+then message will be moved to the ‘Junk’ folder if it contains a positive
+‘X-Spam’ header. This folder will be created under fieldname @code{pathname} if
+it does not yet exist.
+
+@item @code{<opensmtpd-mda>}
+Delegate the delivery to the @code{<opensmtpd-mda>}'s fieldname
+@code{command} (type string) that receives the message on its standard input.
+
+The @code{command} may contain format specifiers that are expanded before use
+(see Format Specifiers).
+@end itemize
+
+@item @code{alias} (default: @code{#f})
+Use the @code{mapping table} for aliases expansion.
+
+@item @code{ttl} (default: @code{#f})
+@code{ttl} is a string specify how long a message may remain in the queue.  It's
+format is @code{n@{s|m|h|d@}}.  eg: @code{"4m"} is four minutes.
+
+@item @code{user} (default: @code{#f} )
+@code{user} is the string username for performing the delivery, to be looked up
+with getpwnam(3).
+
+This is used for virtual hosting where a single username is in charge of
+handling delivery for all virtual users.
+
+This option is not usable with the mbox delivery method.
+
+@item @code{userbase} (default: @code{#f})
+@code{userbase} is an @code{<opensmtpd-table>} record for mapping user
+lookups instead of the getpwnam(3) function.
+
+The fieldnames @code{user} and @code{userbase} are mutually exclusive.
+
+@item @code{virtual} (default: @code{#f})
+@code{virtual} is an @code{<opensmtpd-table>} record is used for virtual
+expansion.
+@end itemize
+
+@item Data Type: opensmtpd-relay
+This data type represents the configuration of an
+@code{<opensmtpd-relay>} record.
+
+@itemize
+@item @code{name} (default: @code{#f})
+@code{name} is the string name of the relay action.
+
+@item @code{backup} (default: @code{#f})
+When @code{#t}, operate as a backup mail exchanger delivering messages to any
+mail exchanger with higher priority.
+
+@item @code{backup-mx} (default: @code{#f})
+Operate as a backup mail exchanger delivering messages to any mail exchanger
+with higher priority than mail exchanger identified as string name.
+
+@item @code{helo} (default: @code{#f})
+Advertise string heloname as the hostname to other mail exchangers during
+the HELO phase.
+
+@item @code{helo-src} (default: @code{#f} )
+ Use the mapping @code{<opensmtpd-table>} to look up a hostname
+matching the source address, to advertise during the HELO phase.
+
+@item @code{domain} (default: @code{#f})
+Do not perform MX lookups but look up destination domain in an
+@code{<opensmtpd-table>} and use matching relay url as relay host.
+
+@item @code{host} (default: @code{#f})
+Do not perform MX lookups but relay messages to the relay host described by
+the string relay-url. The format for relay-url is
+@samp{[proto://[label@@]]host[:port]}. The following protocols are available:
+
+@multitable {aaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{smtp}
+@tab Normal SMTP session with opportunistic STARTTLS (the default).
+@item @code{smtp+tls}
+@tab Normal SMTP session with mandatory STARTTLS@.
+@item @code{smtp+notls}
+@tab Plain text SMTP session without TLS@.
+@item @code{lmtp}
+@tab LMTP session.  port is required.
+@item @code{smtps}
+@tab SMTP session with forced TLS on connection, default port is
+@item
+@tab 465.
+@end multitable
+
+Unless noted, port defaults to 25.
+
+The label corresponds to an entry in a credentials table, as documented in
+@code{man table}. It is used with the @code{"smtp+tls"} and @code{"smtps"} protocols for
+authentication. Server certificates for those protocols are verified by
+default.
+
+@item @code{pki} (default: @code{#f})
+For secure connections, use the certificate associated with
+@code{<opensmtpd-pki>} (declared in a pki directive) to prove the
+client's identity to the remote mail server.
+
+@item @code{srs} (default: @code{#f})
+If @code{#t}, then when relaying a mail resulting from a forward, use the Sender
+Rewriting Scheme to rewrite sender address.
+
+@item @code{tls} (default: @code{#f}) boolean or string ``no-verify''
+When @code{#t}, Require TLS to be used when relaying, using mandatory STARTTLS by
+default. When used with a smarthost, the protocol must not be
+@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not require a valid
+certificate.
+
+@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table>}
+Use the alist @code{<opensmtpd-table>} for connecting to relay-url
+using credentials. This option is usable only with fieldname @code{host} option.
+
+@item @code{mail-from} (default: @code{#f}) string
+Use the string mailaddress as MAIL FROM address within the SMTP transaction.
+
+@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-table>}
+Use the string or @code{<opensmtpd-table>} sourceaddr for the
+source IP address, which is useful on machines with multiple interfaces. If
+the list contains more than one address, all of them are used in such a way
+that traffic is routed as efficiently as possible.
+@end itemize
+
+@item Data Type: opensmtpd-filter
+This data type represents the configuration of an
+@code{<opensmtpd-filter>}. This is the filter record one should use
+if they want to use an external package to filter email eg: rspamd or
+spamassassin.
+
+@itemize
+@item @code{name} (default: @code{#f})
+The string name of the filter.
+
+@item @code{proc} (default: @code{#f})
+The string command or process name.  If @code{proc-exec} is @code{#t}, @code{proc} is
+treated as a command to execute.  Otherwise, it is a process name.
+
+@item @code{proc-exec} (default: @code{#f})
+If @code{#t}, then execute the command in @code{proc}.
+@end itemize
+
+@item Data Type: opensmtpd-filter-phase
+This data type represents the configuration of an
+@code{<opensmtpd-filter-phase>}.
+
+In a regular workflow, @code{smtpd(8)} may accept or reject a message
+based only on the content of envelopes. Its decisions are about the
+handling of the message, not about the handling of an active session.
+
+Filtering extends the decision making process by allowing
+@code{smtpd(8)} to stop at each phase of an SMTP session, check that
+options are met, then decide if a session is allowed to move forward.
+
+With filtering via an @code{<opensmtpd-filter-phase>} record, a
+session may be interrupted at any phase before an envelope is complete. A
+message may also be rejected after being submitted, regardless of whether the
+envelope was accepted or not.
+
+@itemize
+@item @code{name} (default: @code{#f})
+
+The string name of the filter phase.
+
+@item @code{phase-name} (default: @code{#f})
+The string name of the phase. Valid values are:
+
+@multitable {aaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"connect"}
+@tab upon connection, before a banner is displayed
+@item @code{"helo"}
+@tab after HELO command is submitted
+@item @code{"ehlo"}
+@tab after EHLO command is submitted
+@item @code{"mail-from"}
+@tab after MAIL FROM command is submitted
+@item @code{"rcpt-to"}
+@tab after RCPT TO command is submitted
+@item @code{"data"}
+@tab after DATA command is submitted
+@item @code{"commit"}
+@tab after message is fully is submitted
+@end multitable
+
+@item @code{options} (default @code{#f})
+A list of unique @code{<opensmtpd-option>} records.
+
+At each phase, various options, specified by a list of
+@code{<opensmtpd-option>}, may be checked. The
+@code{<opensmtpd-option>}'s fieldname @code{option} values of:
+@code{"fcrdns"}, @code{"rdns"}, and @code{"src"} data are available in
+all phases, but other data must have been already submitted before they
+are available. Options with a @code{<table>} next to them require the
+@code{<opensmtpd-option>}'s fieldname @code{data} to be an
+@code{<opensmtpd-table>}. There are the available options:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"fcrdns"}
+@tab forward-confirmed reverse DNS is valid
+@item @code{"rdns"}
+@tab session has a reverse DNS
+@item @code{"rdns"} <table>
+@tab session has a reverse DNS in table
+@item @code{"src"} <table>
+@tab source address is in table
+@item @code{"helo"} <table>
+@tab helo name is in table
+@item @code{"auth"}
+@tab session is authenticated
+@item @code{"auth"} <table>
+@tab session username is in table
+@item @code{"mail-from"} <table>
+@tab sender address is in table
+@item @code{"rcpt-to"} <table>
+@tab recipient address is in table
+@end multitable
+
+These conditions may all be negated by setting
+@code{(opensmtpd-option (bool #f))}.
+
+Any conditions that require a table may indicate that tables include regexs
+setting @code{(opensmtpd-option (regex #t))}.
+
+@item @code{decision}
+A string decision to be taken. Some decisions require an @code{message}
+or @code{value}.  The value and message may be put in the
+@code{<opensmtpd-option>}'s fieldname @code{data}.  Valid strings are:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @code{"bypass"}
+@tab the session or transaction bypasses filters
+@item @code{"disconnect"} message
+@tab the session is disconnected with message
+@item @code{"junk"}
+@tab the session or transaction is junked,
+@item
+@tab  i.e., an ‘X-Spam: yes’ header is added to
+@item
+@tab any messages
+@item @code{"reject"} message
+@tab the command is rejected with message
+@item @code{"rewrite"} value
+@tab the command parameter is rewritten with value
+@end multitable
+
+Decisions that involve a message require that the message be RFC valid,
+meaning that they should either start with a 4xx or 5xx status code.
+Descisions can be taken at any phase, though junking can only happen before
+a message is committed.
+
+@item @code{message} (default @code{#f})
+A string message beginning with a 4xx or 5xx status code.
+
+@item @code{value} (default: @code{#f})
+A number value.  @code{value} and @code{message} are mutually exclusive.
+@end itemize
+
+@item Data Type: opensmtpd-option
+This data type represents the configuration of an
+@code{<opensmtpd-option>}, which is used by
+@code{<opensmtpd-filter-phase>} and @code{<opensmtpd-match>}
+to match various options for email.
+
+@itemize
+@item @code{option} (default @code{#f}) string
+
+A string option to be taken. Some options require the fieldname
+@code{data} to have a string or an @code{<opensmtpd-table>}. When the
+option record is used inside of an @code{<opensmtpd-filter-phase>}, then
+valid strings for fieldname @code{option} are:
+
+@itemize
+@item @code {"fcrdns"}
+@item @code {"rdns"}
+@item @code {"src"}
+@item @code {"helo"}
+@item @code {"auth"}
+@item @code {"mail-from"}
+@item @code {"rcpt-to"}
+@end itemize
+
+When @code{<opensmtpd-option>} is used inside of an
+@code{<opensmtpd-match>}, then valid strings for fieldname @code{option}
+are:
+
+@itemize
+@item @code {"for"}
+@item @code {"for any"}
+@item @code {"for local"}
+@item @code {"for domain"}
+@item @code {"for rcpt-to"}
+@item @code {"from any"}
+@item @code {"from auth"}
+@item @code {"from local"}
+@item @code {"from mail-from"}
+@item @code {"from rdns"}
+@item @code {"from socket"}
+@item @code {"from src"}
+@item @code {"auth"}
+@item @code {"helo"}
+@item @code {"mail-from"}
+@item @code {"rcpt-to"}
+@item @code {"tag"}
+@item @code {"tls"}
+@end itemize
+
+@item @code{data} (default @code{#f}) string | @code{<opensmtpd-table>}
+Some options require a string or @code{<opensmtpd-table>} to be
+present. One would specify that table here.
+
+@item @code{regex} (default: @code{#f}) boolean
+Any options using a table may indicate that tables hold regular
+expressions by setting this option to @code{#t}.
+
+@item @code{bool} (default: @code{#t}) boolean
+When @code{(bool #f)}, this option record is negated.
+@end itemize
+
+@item Data Type: opensmtpd-table
+This data type represents the configuration of an
+@code{<opensmtpd-table>}.
+
+@itemize
+@item @code{name} (default @code{#f})
+@code{name} is the name of the @code{<opensmtpd-table>} record.
+
+@item @code{data} (default: @code{#f}) string | list | alist | nested-list
+@code{data} expects a string, a list of strings, an alist of strings, or
+a nested list of strings.
+eg:
+
+@itemize
+
+@item string
+@lisp
+(data "dev@@gnu.org")
+@end lisp
+
+A table of this type is called a @code{string table}.
+
+@item list
+@lisp
+(data (list ("gnu.org" "fsf.org")))
+@end lisp
+
+A table of this type is called a @code{list table}.
+
+@item alist
+@lisp
+(data '(("james" . "$encryptedPassword")
+        ("jennifer" . "$encryptedPassword2)))
+@end lisp
+
+A table of this type is called a @code{mapping table}.
+
+@item nested-list
+@lisp
+(data '(("user1" "root@@gnu.org" "admin@@gnu.org")
+        ("user2" "james@@guix.gnu.org" "sarah@@fsf.org")))
+@end lisp
+
+A table of this type is also called a @code{mapping table}.
+
+@end itemize
+@end itemize
+
+@item Data Type: opensmtpd-pki
+This data type represents the configuration of an
+@code{<opensmtpd-pki>}.
+
+@itemize
+@item @code{domain} (default @code{#f})
+@code{domain} is the string name of the @code{<opensmtpd-pki>} record.
+
+@item @code{cert} (default: @code{#f})
+@code{cert} (default: @code{#f})
+
+@code{cert} is the string certificate filename to use for this pki.
+
+@item @code{key} (default: @code{#f})
+@code{key} is the string certificate falename to use for this pki.
+
+@item @code{dhe} (default: @code{"none"})
+Specify the DHE string parameter to use for DHE cipher suites with host
+pkiname. Valid parameter values are @code{"none"}, @code{"legacy"}, or
+@code{"auto"}. For @code{"legacy"}, a fixed key length of 1024 bits is
+used, whereas for @code{"auto"}, the key length is determined
+automatically. The default is @code{"none"}, which disables DHE cipher
+suites.
+@end itemize
+
+@item Data Type: opensmtpd-maildir
+@itemize
+@item @code{pathname} (default: @code{"~/Maildir"})
+Deliver the message to the maildir if pathname if specified, or by default
+to @code{"~/Maildir"}.
+
+The pathname may contain format specifiers that are expanded before use
+(see FORMAT SPECIFIERS).
+
+@item @code{junk} (default: @code{#f})
+If the junk argument is @code{#t}, then the message will be moved to the @samp{‘Junk’}
+folder if it contains a positive @samp{‘X-Spam’} header. This folder will be
+created under pathname if it does not yet exist.
+@end itemize
+
+@item Data Type: opensmtpd-mda
+This record lets you delegate the delivery to a command that receives
+the message on its standard input.
+
+@itemize
+@item @code{name}
+The string name for this MDA command.
+
+@item @code{command}
+The command to that delivers the mail.
+
+The command may contain format specifiers that are expanded before use (see
+FORMAT SPECIFIERS).
+@end itemize
+
+@item Data Type: opensmtpd-queue
+@itemize
+@item @code{compression} (default @code{#f})
+Store queue files in a compressed format. This may be useful to save disk
+space.
+
+@item @code{encryption} (default @code{#f})
+Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If no key is specified, it is
+read with getpass(3). If the string stdin or a single dash (‘-’) is given
+instead of a key, the key is read from the standard input.
+
+@item @code{ttl-delay} (default @code{#f})
+Set the default expiration time for temporarily undeliverable messages,
+given as a positive decimal integer followed by a unit s, m, h, or d. The
+default is four days (@code{"4d"}).
+@end itemize
+
+@item Data Type: opensmtpd-smtp
+Data type representing an @code{<opensmtpd-smtp>} record.
+
+@itemize
+@item @code{ciphers} (default: @code{#f})
+Set the control string for SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default is
+         ``HIGH:!aNULL:!MD5''.
+
+@item @code{limit-max-mails} (default: @code{100})
+Limit the number of messages to count for each sessio
+
+@item @code{limit-max-rcpt} (default: @code{1000})
+Limit the number of recipients to count for each transaction.
+
+@item @code{max-message-size} (default: @code{35M})
+Reject messages larger than size, given as a positive number of bytes or as
+a string to be parsed with scan@math{_scaled}(3).
+
+@item @code{sub-addr-delim character} (default: @code{+})
+When resolving the local part of a local email address, ignore the ASCII
+character and all characters following it. This is helpful for email
+filters. @samp{"admin+bills@@gnu.org"} is the same email address as
+@samp{"admin@@gnu.org"}. BUT an email filter can filter emails addressed to first
+email address into a 'Bills' email folder.
+@end itemize
+
+@item Data Type: opensmtpd-srs
+Use this record to set up the Sender Rewriting Scheme (SRS).
+
+@itemize
+@item @code{key} (default: @code{#f})
+Set the secret key to use for SRS, the Sender Rewriting Scheme.
+
+@item @code{backup-key} (default: @code{#f})
+Set a backup secret key to use as a fallback for SRS@. This can be used to
+implement SRS key rotation.
+
+@item @code{ttl-delay} (default: @code{"4d"})
+Set the time-to-live delay for SRS envelopes. After this delay, a bounce
+reply to the SRS address will be discarded to limit risks of forged
+addresses.
+@end itemize
+
+@item Format Specifiers
+Some configuration records support expansion of their parameters at
+runtime. Such records (for example
+@code{<opensmtpd-maildir>}, @code{<opensmtpd-mda>}) may use
+format specifiers which are expanded before delivery or relaying. The
+following formats are currently supported:
+
+@multitable {aaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{sender@}}
+@tab sender email address, may be empty string
+@item @samp{%@{sender.user@}}
+@tab user part of the sender email address, may be empty
+@item @samp{%@{sender.domain@}}
+@tab domain part of the sender email address, may be empty
+@item @samp{%@{rcpt@}}
+@tab recipient email address
+@item @samp{%@{rcpt.user@}}
+@tab user part of the recipient email address
+@item @samp{%@{rcpt.domain@}}
+@tab domain part of the recipient email address
+@item @samp{%@{dest@}}
+@tab recipient email address after expansion
+@item @samp{%@{dest.user@}}
+@tab user part after expansion
+@item @samp{%@{dest.domain@}}
+@tab domain part after expansion
+@item @samp{%@{user.username@}}
+@tab local user
+@item @samp{%@{user.directory@}}
+@tab home directory of the local user
+@item @samp{%@{mbox.from@}}
+@tab name used in mbox From separator lines
+@item @samp{%@{mda@}}
+@tab mda command, only available for mda wrappers
+@end multitable
+
+Expansion formats also support partial expansion using the optional bracket notations
+with substring offset.  For example, with recipient domain @samp{“example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt.domain[0]@}}
+@tab expands to “e”
+@item @samp{%@{rcpt.domain[1]@}}
+@tab expands to “x”
+@item @samp{%@{rcpt.domain[8:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[-3:]@}}
+@tab expands to “org”
+@item @samp{%@{rcpt.domain[0:6]@}}
+@tab expands to “example”
+@item @samp{%@{rcpt.domain[0:-4]@}}
+@tab expands to “example”
+@end multitable
+
+In addition, modifiers may be applied to the token.  For example, with recipient
+@samp{“User+Tag@@Example.org”}:
+
+@multitable {aaaaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt:lowercase@}}
+@tab expands to “user+tag@@example.org”
+@item @samp{%@{rcpt:uppercase@}}
+@tab expands to “USER+TAG@@EXAMPLE.ORG”
+@item @samp{%@{rcpt:strip@}}
+@tab expands to “User@@Example.org”
+@item @samp{%@{rcpt:lowercasestrip@}}
+@tab expands to “user@@example.org”
+@end multitable
+
+For security concerns, expanded values are sanitized and potentially dangerous
+characters are replaced with ‘:’. In situations where they are desirable, the
+“raw” modifier may be applied. For example, with recipient
+@samp{“user+t?g@@example.org”}:
+
+@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
+@item @samp{%@{rcpt@}}
+@tab expands to “user+t:g@@example.org”
+@item @samp{%@{rcpt:raw@}}
+@tab expands to “user+t?g@@example.org”
+@end multitable
+@end itemize
+
 @subsubheading Exim Service
 
 @cindex mail transfer agent (MTA)
diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
index 43f144a42d..4175cab375 100644
--- a/gnu/services/mail.scm
+++ b/gnu/services/mail.scm
@@ -35,6 +35,10 @@ (define-module (gnu services mail)
   #:use-module (gnu packages admin)
   #:use-module (gnu packages dav)
   #:use-module (gnu packages tls)
+  #:use-module (guix i18n)
+  #:use-module (guix diagnostics)
+  #:use-module (guix ui)
+  #:use-module (guix utils)
   #:use-module (guix records)
   #:use-module (guix packages)
   #:use-module (guix gexp)
@@ -58,10 +62,149 @@ (define-module (gnu services mail)
             mailbox-configuration
             namespace-configuration
 
+            opensmtpd-table
+            opensmtpd-table?
+            opensmtpd-table-name
+            opensmtpd-table-data
+
+            opensmtpd-ca
+            opensmtpd-ca?
+            opensmtpd-ca-name
+            opensmtpd-ca-file
+
+            opensmtpd-pki
+            opensmtpd-pki?
+            opensmtpd-pki-domain
+            opensmtpd-pki-cert
+            opensmtpd-pki-key
+            opensmtpd-pki-dhe
+
+            opensmtpd-local-delivery
+            opensmtpd-local-delivery?
+            opensmtpd-local-delivery-method
+            opensmtpd-local-delivery-alias
+            opensmtpd-local-delivery-ttl
+            opensmtpd-local-delivery-user
+            opensmtpd-local-delivery-userbase
+            opensmtpd-local-delivery-virtual
+            opensmtpd-local-delivery-wrapper
+
+            opensmtpd-maildir
+            opensmtpd-maildir?
+            opensmtpd-maildir-pathname
+            opensmtpd-maildir-junk
+
+            opensmtpd-mda
+            opensmtpd-mda-name
+            opensmtpd-mda-command
+
+            opensmtpd-lmtp
+            opensmtpd-lmtp-destination
+            opensmtpd-lmtp-rcpt
+
+            opensmtpd-relay
+            opensmtpd-relay?
+            opensmtpd-relay-name
+            opensmtpd-relay-backup
+            opensmtpd-relay-backup-mx
+            opensmtpd-relay-helo
+            opensmtpd-relay-domain
+            opensmtpd-relay-host
+            opensmtpd-relay-pki
+            opensmtpd-relay-srs
+            opensmtpd-relay-tls
+            opensmtpd-relay-auth
+            opensmtpd-relay-mail-from
+            opensmtpd-relay-src
+
+            opensmtpd-option
+            opensmtpd-option?
+            opensmtpd-option-option
+            opensmtpd-option-bool
+            opensmtpd-option-regex
+            opensmtpd-option-data
+
+            opensmtpd-filter-phase
+            opensmtpd-filter-phase?
+            opensmtpd-filter-phase-name
+            opensmtpd-filter-phase-phase
+            opensmtpd-filter-phase-options
+            opensmtpd-filter-phase-decision
+            opensmtpd-filter-phase-message
+            opensmtpd-filter-phase-value
+
+            opensmtpd-filter
+            opensmtpd-filter?
+            opensmtpd-filter-name
+            opensmtpd-filter-proc
+
+            opensmtpd-interface
+            opensmtpd-interface?
+            opensmtpd-interface-interface
+            opensmtpd-interface-family
+            opensmtpd-interface-auth
+            opensmtpd-interface-auth-optional
+            opensmtpd-interface-filters
+            opensmtpd-interface-hostname
+            opensmtpd-interface-hostnames
+            opensmtpd-interface-mask-src
+            opensmtpd-interface-disable-dsn
+            opensmtpd-interface-pki
+            opensmtpd-interface-port
+            opensmtpd-interface-proxy-v2
+            opensmtpd-interface-received-auth
+            opensmtpd-interface-senders
+            opensmtpd-interface-masquerade
+            opensmtpd-interface-secure-connection
+            opensmtpd-interface-tag
+
+            opensmtpd-socket
+            opensmtpd-socket?
+            opensmtpd-socket-filters
+            opensmtpd-socket-mask-src
+            opensmtpd-socket-tag
+
+            opensmtpd-match
+            opensmtpd-match?
+            opensmtpd-match-action
+            opensmtpd-match-options
+
+            opensmtpd-smtp
+            opensmtpd-smtp?
+            opensmtpd-smtp-ciphers
+            opensmtpd-smtp-limit-max-mails
+            opensmtpd-smtp-limit-max-rcpt
+            opensmtpd-smtp-max-message-size
+            opensmtpd-smtp-sub-addr-delim character
+
+            opensmtpd-srs
+            opensmtpd-srs?
+            opensmtpd-srs-key
+            opensmtpd-srs-backup-key
+            opensmtpd-srs-ttl-delay
+
+            opensmtpd-queue
+            opensmtpd-queue?
+            opensmtpd-queue-compression
+            opensmtpd-queue-encryption
+            opensmtpd-queue-ttl-delay
+
             opensmtpd-configuration
             opensmtpd-configuration?
+            opensmtpd-package
+            opensmtpd-config-file
+            opensmtpd-configuration-bounce
+            opensmtpd-configuration-cas
+            opensmtpd-configuration-interfaces
+            opensmtpd-configuration-socket
+            opensmtpd-configuration-includes
+            opensmtpd-configuration-matches
+            ;;opensmtpd-configuration-mda-wrappers
+            opensmtpd-configuration-mta-max-deferred
+            opensmtpd-configuration-srs
+            opensmtpd-configuration-smtp
+            opensmtpd-configuration-queue
             opensmtpd-service-type
-            %default-opensmtpd-config-file
 
             mail-aliases-service-type
 
@@ -1641,22 +1784,2351 @@ (define (generate-dovecot-documentation)
        (listeners unix-listener-configuration fifo-listener-configuration
                   inet-listener-configuration))
       (protocol-configuration ,protocol-configuration-fields))
-  'dovecot-configuration))
+   'dovecot-configuration))
 
 \f
-;;;
 ;;; OpenSMTPD.
 ;;;
+;;; This next bit of code helps me create my own sanitizer functions.
+
+;; some fieldnames have a default value of #f, which is ok.  They cannot have
+;; a value of #t.
+;; for example opensmtpd-table-data can be #f, BUT NOT true.
+;; my/sanitize procedure tests values to see if they are of the right kind.
+;; procedure false? is needed to allow fields like 'values' to be blank,
+;; (empty), or #f BUT also have a value like a list of strings.
+(define (false? var)
+  (eq? #f var))
+
+;; TODO I have to have this procedure, or I need to change my/sanitize
+;; procedure.
+(define (my-file-exists? file)
+  (and (string? file)
+       (access? file F_OK)))
+
+;; This procedure takes in a var and a list of procedures.  It loops through
+;; list of procedures passing in var to each.
+;; if one procedure returns #t, the function returns true.  Otherwise #f.
+;; TODO for fun rewrite this using map
+;; If I rewrote it in map, then it may help with sanitizing.
+;; eg: I could then potentially easily sanitize vars with lambda procedures.
+(define (is-value-right-type? var list-of-procedures record fieldname)
+  (if (null? list-of-procedures)
+      #f
+      (if ((car list-of-procedures) var)
+          #t
+          (is-value-right-type? var (cdr list-of-procedures) record
+                                fieldname))))
+
+;; converts strings like this:
+;; "apple, ham, cherry" -> "apple, ham, or cherry"
+;; "pineapple" -> "pinneapple".
+;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
+(define (add-comma-or string)
+  (define last-comma-location (string-rindex string #\,))
+  (if last-comma-location
+      (if (string-contains string ", or" last-comma-location)
+          string
+          (string-replace string ", or" last-comma-location
+                          (+ 1 last-comma-location)))
+      string))
+
+
+(define (list-of-procedures->string procedures)
+  (define string
+    (let loop ((procedures procedures))
+      (if (null? procedures)
+          ""
+          (begin
+            (string-append
+             (cond ((eq? false? (car procedures))
+                    "#f, ")
+                   ((eq? boolean? (car procedures))
+                    "a boolean, ")
+                   ((eq? string? (car procedures))
+                    "a string, ")
+                   ((eq? integer? (car procedures))
+                    "an integer, ")
+                   ((eq? list-of-strings? (car procedures))
+                    "a list of strings, ")
+                   ((eq? assoc-list? (car procedures))
+                    "an association list of strings, ")
+                   ((eq? nested-list? (car procedures))
+                    "a nested-list of strings, ")
+                   ((eq? opensmtpd-pki? (car procedures))
+                    "an <opensmtpd-pki> record, ")
+                   ((eq? opensmtpd-table? (car procedures))
+                    "an <opensmtpd-table> record, ")
+                   ((eq? list-of-opensmtpd-match? (car procedures))
+                    "a list of unique <opensmtpd-match> records, ")
+                   ((eq? list-of-strings-or-gexps? (car procedures))
+                    "a list of strings or gexps, ")
+                   ;; TODO can I remove the next two procedures?
+                   ;; tables-data-are-a* ?  I think I can.
+                   ((eq? tables-data-are-assoc-list? (car procedures))
+                    (string-append
+                     "an <opensmtpd-table> record whose fieldname 'data' are "
+                     "an assoc-list.\nFor example: (opensmtpd-table  "
+                     "(name \"hostnames\") , "
+                     "(data '((\"124.394.23.1\" . \"gnu.org\"))))"))
+                   ((eq? tables-data-are-a-list-of-strings?
+                         (car procedures))
+                    (string-append
+                     "on <opensmtpd-table> record whose fieldname 'data' is "
+                     "a list of strings.\n"
+                     "For example: (opensmtpd-table (name \"domains\") , "
+                     "(data (list \"gnu.org\" \"guix.gnu.org\")))"))
+                   ((eq? my-file-exists? (car procedures))
+                    "a file, ")
+                   (else "has an incorrect value, "))
+             (loop (cdr procedures)))))))
+  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
+
+(define (list-of-strings-or-gexps? list)
+  (and (list? list)
+       (cond ((null? list)
+              #t)
+             ((or (string? (car list))
+                  (gexp? (car list))
+                  (local-file? (car list))
+                  (file-append? (car list))
+                  (plain-file? (car list))
+                  (computed-file? (car list))
+                  (program-file? (car list)))
+              (list-of-strings-or-gexps? (cdr list)))
+             (else #f))))
+
+(define (my/sanitize var record fieldname list-of-procedures)
+  (define try-string
+    (string-append "Try " (list-of-procedures->string list-of-procedures)))
+  (if (is-value-right-type? var list-of-procedures record fieldname)
+      var
+      (begin
+        (cond ((string? var)
+               (report-error (G_ "(~a \"~a\") is invalid.~%") fieldname var))
+              ((or (number? var) (boolean? var))
+              (report-error (G_ "(~a ~a) is invalid.~%") fieldname var) )
+              (else
+               (report-error (G_ "(~a ...) is invalid.~%Value is: ~a~%")
+                             fieldname var)))
+        (display-hint (G_ try-string))
+        (throw 'bad! var))))
+
+;;; The Opensmtpd records.
+
+;; Some example opensmtpd-tables:
+;;
+;;  (opensmtpd-table (name "root accounts")
+;;                   (data '(("joshua" . "root@dismail.de")
+;;                           ("joshua" . "postmaster@dismail.de"))))
+;;  (opensmtpd-table (name "root accounts")
+;;                   (data (list "mysite.me" "your-site.com")))
+;;  TODO: How am I supporting file: or db: tables?
+;;  Perhaps I should just automatically convert the table to a database table
+;;  if the data gets large enough.  What would be sufficently large enough?
+(define-record-type* <opensmtpd-table>
+  opensmtpd-table make-opensmtpd-table
+  opensmtpd-table?
+  (name opensmtpd-table-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-table" "name"
+                                 (list string?)))))
+  ;; FIXME Support an aliasing table as described here:
+  ;; https://man.openbsd.org/table.5
+  ;; One may have to use the record file for this.  I don't think tables
+  ;; support a table like this:
+  ;; table "name" { joshua = joshua@gnucode.me,joshua@gnu-hurd.com, \
+  ;;    joshua@propernaming.org, root = root@gnucode.me }
+  ;; If values is an absolute filename, then it will use said filename to
+  ;; house the table info. filename must be an absolute filename.
+  (data opensmtpd-table-data
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-table" "data"
+                                   (list list-of-strings? assoc-list?
+                                         nested-list?))))))
+
+(define-record-type* <opensmtpd-ca>
+  opensmtpd-ca make-opensmtpd-ca
+  opensmtpd-ca?
+  (name opensmtpd-ca-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca" "name" (list string?)))))
+  (file opensmtpd-ca-file
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-ca" "file"
+                                 (list my-file-exists?))))))
+
+(define-record-type* <opensmtpd-pki>
+  opensmtpd-pki make-opensmtpd-pki
+  opensmtpd-pki?
+  (domain opensmtpd-pki-domain
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-pki" "domain"
+                                   (list string?)))))
+  ;; TODO/FIXME this should probably be a list of files.  The opensmtpd
+  ;; documentation says that you could have a list of files:
+  ;;
+  ;; pki pkiname cert certfile
+  ;; Associate certificate file certfile with host pkiname, and use that file
+  ;; to prove the identity of the mail server to clients.  pkiname is the
+  ;; server's name, derived from the default hostname or set using either
+  ;; /gnu/store/2d13sdz76ldq8zgwv4wif0zx7hkr3mh2-opensmtpd-6.8.0p2/etc/mailname
+  ;; or using the hostname directive.  If a fallback certificate or SNI is
+  ;; wanted, the ‘*’ wildcard may be used as pkiname.
+
+  ;; A certificate chain may be created by appending one or many certificates,
+  ;; including a Certificate Authority certificate, to certfile.  The creation
+  ;; of certificates is documented in starttls(8).
+  (cert opensmtpd-pki-cert
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-pki" "cert"
+                                 (list my-file-exists?)))))
+  (key opensmtpd-pki-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-pki" "key"
+                                (list my-file-exists?)))))
+  ; todo sanitize this. valid parameters are "none", "legacy", or "auto".
+  (dhe opensmtpd-pki-dhe
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-dhe" "dhe"
+                                (list false? string?))))))
+
+(define-record-type* <opensmtpd-lmtp>
+  opensmtpd-lmtp make-opensmtpd-lmtp
+  opensmtpd-lmtp?
+  (destination opensmtpd-lmtp-destination
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-lmtp" "destination"
+                                        (list string?)))))
+  (rcpt-to opensmtpd-lmtp-rcpt-to
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-lmtp" "rcpt-to"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-mda>
+  opensmtpd-mda make-opensmtpd-mda
+  opensmtpd-mda?
+  (name opensmtpd-mda-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-mda" "name"
+                                 (list string?)))))
+  ;; TODO should I allow this command to be a gexp?
+  (command opensmtpd-mda-command
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-mda" "command"
+                                    (list string?))))))
+
+(define-record-type* <opensmtpd-maildir>
+  opensmtpd-maildir make-opensmtpd-maildir
+  opensmtpd-maildir?
+  (pathname opensmtpd-maildir-pathname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-maildir" "pathname"
+                                     (list false? string?)))))
+  (junk opensmtpd-maildir-junk
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-maildir" "junk"
+                                 (list boolean?))))))
+
+(define-record-type* <opensmtpd-local-delivery>
+  opensmtpd-local-delivery make-opensmtpd-local-delivery
+  opensmtpd-local-delivery?
+  (name opensmtpd-local-delivery-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-local-delivery" "name"
+                                 (list string?)))))
+  (method opensmtpd-local-delivery-method
+          (default "mbox")
+          (sanitize (lambda (var)
+                      (define fieldname "method")
+                      (define options (list "mbox" "expand-only"
+                                            "forward-only"))
+                      (define options-plus-records
+                            (append options (list "(opensmtpd-lmtp ...)"
+                                                  "(opensmtpd-maildir ...)"
+                                                  "(opensmtpd-mda ...)")))
+                      (cond ((or (opensmtpd-lmtp? var)
+                                 (opensmtpd-maildir? var)
+                                 (opensmtpd-mda? var)
+                                 (member var options))
+                             var)
+                            (else
+                             (begin
+                               (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                             fieldname var)
+                               (display-hint
+                                (G_ (hint-string
+                                     var
+                                     options-plus-records
+                                     #:fieldname fieldname)))
+                               (throw 'bad! var)))))))
+  (alias opensmtpd-local-delivery-alias
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-local-delivery" "alias"
+                                  (list false?
+                                        tables-data-are-assoc-list?)))))
+  (ttl opensmtpd-local-delivery-ttl
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-local-delivery" "ttl"
+                                (list false? string?)))))
+  (user opensmtpd-local-delivery-user
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-local-delivery" "user"
+                                 (list false? string?)))))
+  (userbase opensmtpd-local-delivery-userbase
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-local-delivery" "userbase"
+                                (list false?
+                                      tables-data-are-assoc-list?)))))
+  (virtual opensmtpd-local-delivery-virtual
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-local-delivery" "virtual"
+                                    (list
+                                     false?
+                                     tables-data-are-assoc-list?)))))
+  (wrapper opensmtpd-local-delivery-wrapper
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-local-delivery" "wrapper"
+                                    (list false? string?))))))
+
+(define-record-type* <opensmtpd-relay>
+  opensmtpd-relay make-opensmtpd-relay
+  opensmtpd-relay?
+  (name opensmtpd-relay-name
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "name"
+                                 (list string?))))
+        (default #f))
+  (backup opensmtpd-relay-backup ;; boolean
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "backup"
+                                   (list boolean?)))))
+  (backup-mx opensmtpd-relay-backup-mx ;; string mx name
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-relay" "backup-mx"
+                                      (list false? string?)))))
+  (helo opensmtpd-relay-helo
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "helo"
+                                 (list false? string?))))
+        (default #f))
+  (helo-src opensmtpd-relay-helo-src
+        (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "helo-src"
+                                   (list false? string?
+                                         tables-data-are-assoc-list?))))
+        (default #f))
+  (domain opensmtpd-relay-domain
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-relay" "domain"
+                                   (list false? opensmtpd-table?))))
+          (default #f))
+  (host opensmtpd-relay-host
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "host"
+                                 (list false? string?))))
+        (default #f))
+  (pki opensmtpd-relay-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "pki"
+                                (list false? opensmtpd-pki?)))))
+  (srs opensmtpd-relay-srs
+       (default #f)
+       (lambda (var)
+         (my/sanitize var "opensmtpd-relay" "srs"
+                      (list boolean?))))
+  (tls opensmtpd-relay-tls
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-relay" "tls"
+                                (list false? string?)))))
+  ;; the table here looks like:
+  ;; label1    user:password
+  ;; label2    user2:password2
+  ;; It is documented in the credentials table in man table
+  (auth opensmtpd-relay-auth
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-relay" "auth"
+                                 (list false?
+                                       tables-data-are-assoc-list?))))
+        (default #f))
+  (mail-from opensmtpd-relay-mail-from
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-relay" "mail-from"
+                                      (list false? string?))))
+             (default #f))
+  ;; string "127.0.0.1" or "<interface>" or "<table of IP addresses>"
+  ;; TODO should I do some sanitizing to make sure that the string?
+  ;; here is actually an IP address or a valid interface?
+  (src opensmtpd-relay-src
+       (sanitize
+        (lambda (var)
+          (my/sanitize var "opensmtpd-relay" "src"
+                       (list false? string?
+                             tables-data-are-a-list-of-strings?))))
+       (default #f)))
+
+;; this record is used by <opensmtpd-filter-phase> &
+;; <opensmtpd-match>
+(define-record-type* <opensmtpd-option>
+  opensmtpd-option make-opensmtpd-option
+  opensmtpd-option?
+  (option opensmtpd-option-option
+          (default #f)
+          (sanitize (lambda (var)
+                      (my/sanitize var "opensmtpd-option" "option"
+                                   (list string?)))))
+  (bool opensmtpd-option-bool
+       (default #t)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-option" "not"
+                                (list boolean?)))))
+  (regex opensmtpd-option-regex
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option" "regex"
+                                  (list boolean?)))))
+  (data opensmtpd-option-data
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-option" "data"
+                                  (list false? string? opensmtpd-table?))))))
+
+(define-record-type* <opensmtpd-filter-phase>
+  opensmtpd-filter-phase make-opensmtpd-filter-phase
+  opensmtpd-filter-phase?
+  (name opensmtpd-filter-phase-name ;; string
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter-phase" "name"
+                                 (list string?)))))
+  (phase opensmtpd-filter-phase-phase ;; string
+              (default #f)
+              (sanitize
+               (lambda (var)
+                 (define options
+                   (list "connect" "helo" "ehlo" "mail-from"
+                         "rcpt-to" "data" "commit"))
+                 (define fieldname "phase")
+                 (if (and (string? var)
+                          (member var options))
+                     var
+                     (begin
+                       (report-error
+                        (G_
+                         "(opensmtpd-filter-phase ... (~a \"~a\")) is invalid.~%")
+                        fieldname var)
+                       (display-hint
+                        (G_ (hint-string var options
+                                         #:fieldname fieldname)))
+                       (throw 'bad! var))))))
+  (options opensmtpd-filter-phase-options
+           (default #f)
+           (sanitize
+            (lambda (var)
+              (cond
+               ((false? var)
+                (report-error (G_ ""))
+                (display "(opensmtpd-filter-phase (options #f)) is invalid.\n")
+                (display-hint
+                 (G_ "Try a list of (opensmtpd-option) records.\n"))
+                (throw 'bad! #f))
+               ((not (list-of-opensmtpd-option? var))
+                (report-error (G_ ""))
+                (display "(opensmtpd-filter-phase (options ...) is invalid.\n")
+                (display-hint
+                 (G_ "Try a list of (opensmtpd-option) records.\n"))
+                (throw 'bad! var))
+               (else (sanitize-options-for-filter-phase var))))))
+  (decision opensmtpd-filter-phase-decision
+            (default #f)
+            (sanitize
+             (lambda (var)
+               (define options
+                 (list "bypass" "disconnect"
+                       "reject" "rewrite" "junk"))
+               (define fieldname "decision")
+               (if (and (string? var)
+                        (member var options))
+                   var
+                   (begin
+                     (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                   fieldname var)
+                     (display-hint (G_ (hint-string var options
+                                                    #:fieldname fieldname)))
+                     (throw 'bad! var))))))
+  (message opensmtpd-filter-phase-message
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-filter-phase" "message"
+                                    (list false? string?)))))
+  (value opensmtpd-filter-phase-value
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-filter-phase" "value"
+                                  (list false? number?))))))
+
+(define-record-type* <opensmtpd-filter>
+  opensmtpd-filter make-opensmtpd-filter
+  opensmtpd-filter?
+  (name opensmtpd-filter-name
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "name"
+                                 (list string?)))))
+  (exec opensmtpd-filter-exec
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-filter" "exec"
+                                 (list boolean?)))))
+  ;; a string like "rspamd" or the command to start it like
+  ;; "/path/to/rspamd --option=arg --2nd-option=arg2"
+  ;; OR a list of strings and/or geps.
+  (proc opensmtpd-filter-proc
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-filter" "proc"
+                                      (list string?
+                                            list-of-strings-or-gexps?))))))
+
+;; There is another type of filter that opensmtpd supports, which is a
+;; filter chain. A filter chain is a list of <opensmtpd-filter-phase>s
+;; and/or <opensmtpd-filter>s. This lets you apply several filters under
+;; one filter name.  I could have defined a record type for it, but the
+;; record would only have had two fields: name and list-of-filters.
+;; Why write that as a record?  It makes the user of this service harder.
+;; Instead, just define it as a list, and if a user wants an interface
+;; to make multiple filters, he just appends to the 'filters' fieldname.
+;;
+;; returns #t if list is a unique list of <opensmtpd-filter> or
+;; <opensmtpd-filter-phase>
+;; returns # otherwise
+(define (opensmtpd-filter-chain? %filters)
+  (and (list-of-unique-filter-or-filter-phase? %filters)
+       (< 1 (length %filters))))
+
+(define-record-type* <opensmtpd-interface>
+  opensmtpd-interface make-opensmtpd-interface
+  opensmtpd-interface?
+  ;; interface may be an IP address, interface group, or domain name
+  (interface opensmtpd-interface-interface
+             (default "lo")
+             (sanitize (lambda (var)
+                         (my/sanitize var "interface" "interface"
+                                      (list string?)))))
+  (family opensmtpd-interface-family
+          (default #f)
+          (sanitize
+           (lambda (var)
+             (define options (list "inet4" "inet6"))
+             (define fieldname "family")
+             (cond
+              ((eq? #f var) ;; var == #f
+               var)
+              ((and (string? var)
+                    (member var options))
+               var)
+              (else
+               (begin
+                 (report-error (G_ "(~a \"~a\") is invalid.~%") fieldname var)
+                 (display-hint (G_ (hint-string var options
+                                                #:fieldname fieldname)))
+                 (throw 'bad! var)))))))
+  (auth opensmtpd-interface-auth
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "auth"
+                                 (list boolean?
+                                       tables-data-are-assoc-list?)))))
+  (auth-optional opensmtpd-interface-auth-optional
+                 (default #f)
+                 (sanitize
+                  (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "auth-optional"
+                                 (list boolean?
+                                       tables-data-are-assoc-list?)))))
+  ;; TODO add a ca entry?
+  ;; string FIXME/TODO sanitize this to support a gexp.  That way way the
+  ;; includes directive can include my hacky scheme code that I use
+  ;; for opensmtpd-dkimsign.
+  (filters opensmtpd-interface-filters
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-socket-and-interfaces-filters var))))
+  (hostname opensmtpd-interface-hostname
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-interface" "hostname"
+                                     (list false? string?)))))
+  (hostnames opensmtpd-interface-hostnames
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-interface" "hostnames"
+                                      (list
+                                       false?
+                                       tables-data-are-assoc-list?)))))
+  (mask-src opensmtpd-interface-mask-src
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-interface" "mask-src"
+                                     (list boolean?)))))
+  (disable-dsn opensmtpd-interface-disable-dsn
+          (default #f))
+  (pki opensmtpd-interface-pki
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "pki"
+                                (list false? opensmtpd-pki?)))))
+  (port opensmtpd-interface-port
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-interface" "port"
+                                 (list false? integer?)))))
+  (proxy-v2 opensmtpd-interface-proxy-k2
+            (default #f))
+  (received-auth opensmtpd-interface-received-auth
+                 (default #f))
+  (senders opensmtpd-interface-senders
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-interface" "senders"
+                                    (list false?
+                                          tables-data-are-assoc-list?))))
+           (default #f))
+  (masquerade opensmtpd-interface-masquerade
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-interface" "masquerade"
+                                       (list boolean?))))
+              (default #f))
+  (secure-connection opensmtpd-interface-secure-connection
+                     (default #f)
+                     (sanitize
+                      (lambda (var)
+                        (define options
+                          (list "smtps" "tls" "tls-require"
+                                "tls-require-verify"))
+                        (define fieldname "secure-connection")
+                        (cond ((boolean? var)
+                               var)
+                              ((and (string? var)
+                                    (member var options))
+                               var)
+                              (else
+                               (begin
+                                 (report-error
+                                  (G_ "(~a \"~a\") is invalid.~%")
+                                  fieldname var)
+                                 (display-hint
+                                  (G_ (hint-string var options
+                                                   #:fieldname fieldname)))
+                                 (throw 'bad! var)))))))
+  (tag opensmtpd-interface-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+(define-record-type* <opensmtpd-socket>
+  opensmtpd-socket make-opensmtpd-socket
+  opensmtpd-socket?
+  ;; false or <opensmtpd-filter> or list of <opensmtpd-filter>
+  (filters opensmtpd-socket-filters
+           (sanitize (lambda (var)
+                       (sanitize-socket-and-interfaces-filters
+                        var
+                        #:socket-or-interface "socket")))
+          (default #f))
+  (mask-src opensmtpd-socket-mask-src
+            (default #f)
+            (my/sanitize var "opensmtpd-interface" "mask-src"
+                                (list false? boolean?)))
+  (tag opensmtpd-socket-tag
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-interface" "tag"
+                                (list false? string?))))
+       (default #f)))
+
+
+(define-record-type* <opensmtpd-match>
+  opensmtpd-match make-opensmtpd-match
+  opensmtpd-match?
+  ;;TODO? Perhaps I should add in a reject fieldname.  If reject
+  ;;is #t, then the match record will be a reject match record.
+  ;; (opensmtpd-match (reject #t)) vs. (opensmtpd-match (action 'reject))
+  ;; To do this, I will also have to 'reject' mutually exclusive.
+  ;; AND an match with 'reject' can have no action defined.
+  (action opensmtpd-match-action
+          (default #f)
+          (sanitize
+           (lambda (var)
+             (define fieldname "action")
+             (if (or (opensmtpd-relay? var)
+                     (opensmtpd-local-delivery? var)
+                     (eq? (quote reject) var))
+                 var
+                 (begin
+                   (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                 fieldname var)
+                   (display-hint
+                    (G_ "Try an (opensmtpd-relay) record,
+(opensmtpd-local-delivery) record, or (quote reject)."))
+                   (throw 'bad! var))))))
+  (options opensmtpd-match-options
+           (default #f)
+           (sanitize (lambda (var)
+                       (sanitize-options-for-opensmtpd-match var)))))
+
+(define-record-type* <opensmtpd-smtp>
+  opensmtpd-smtp make-opensmtpd-smtp
+  opensmtpd-smtp?
+  (ciphers opensmtpd-smtp-ciphers
+           (default #f)
+           (sanitize (lambda (var)
+                       (my/sanitize var "opensmtpd-smtp" "ciphers"
+                                    (list false? string?)))))
+  (limit-max-mails opensmtpd-smtp-limit-max-mails
+                   (default #f)
+                   (sanitize (lambda (var)
+                               (my/sanitize var "opensmtpd-smtp"
+                                            "limit-max-mails"
+                                            (list false? integer?)))))
+  (limit-max-rcpt opensmtpd-smtp-limit-max-rcpt
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp"
+                                           "limit-max-rcpt"
+                                           (list false? integer?)))))
+  ;; TODO the user could enter in "zebra" which would break the config.
+  ;; I should sanitize the string to make sure it looks like "50M".
+  (max-message-size opensmtpd-smtp-max-message-size
+                    (default #f)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-smtp"
+                                             "max-message-size"
+                                             (list false? integer?
+                                                   string?)))))
+  ;; FIXME/TODO the sanitize function of sub-addr-delim should accept a
+  ;; string of length one not string?
+  (sub-addr-delim opensmtpd-smtp-sub-addr-delim
+                  (default #f)
+                  (sanitize (lambda (var)
+                              (my/sanitize var "opensmtpd-smtp"
+                                           "sub-addr-delim"
+                                           (list false? integer? string?))))))
+
+(define-record-type* <opensmtpd-srs>
+  opensmtpd-srs make-opensmtpd-srs
+  opensmtpd-srs?
+  (key opensmtpd-srs-key
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-srs" "key"
+                                (list false? boolean? my-file-exists?)))))
+  (backup-key opensmtpd-srs-backup-key
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-srs" "backup-key"
+                                       (list false? integer?
+                                             my-file-exists?)))))
+  ;; TODO the user could set the string to be "zebra", which would break
+  ;; the config.
+  (ttl-delay opensmtpd-srs-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-srs" "ttl-delay"
+                                      (list false? string?))))))
+
+(define-record-type* <opensmtpd-queue>
+  opensmtpd-queue make-opensmtpd-queue
+  opensmtpd-queue?
+  (compression opensmtpd-queue-compression
+               (default #f)
+               (sanitize (lambda (var)
+                           (my/sanitize var "opensmtpd-queue" "compression"
+                                        (list boolean?)))))
+  (encryption opensmtpd-queue-encryption
+              (default #f)
+              (sanitize (lambda (var)
+                          (my/sanitize var "opensmtpd-queue" "encryption"
+                                       (list boolean? string?
+                                             my-file-exists?)))))
+  ;; TODO the user could set the string to be "zebra", which would break
+  ;; the config.
+  (ttl-delay opensmtpd-queue-ttl-delay
+             (default #f)
+             (sanitize (lambda (var)
+                         (my/sanitize var "opensmtpd-queue" "ttl-delay"
+                                      (list false? string?))))))
 
 (define-record-type* <opensmtpd-configuration>
   opensmtpd-configuration make-opensmtpd-configuration
   opensmtpd-configuration?
-  (package     opensmtpd-configuration-package
-               (default opensmtpd))
+  (package opensmtpd-configuration-package
+           (default opensmtpd))
   (config-file opensmtpd-configuration-config-file
-               (default %default-opensmtpd-config-file))
+               (default #f))
+  ;; FIXME/TODO should I include a admd authservid entry?
+  (bounce opensmtpd-configuration-bounce
+          (default #f)
+          (sanitize
+           (lambda (var)
+             (cond ((false? var)
+                    var)
+                   ((and (list? var)
+                         (>= 4 (length var))
+                         (<= 1 (length var))
+                         (list-of-strings? var)
+                         (every (lambda (str)
+                                  (and (<= 2 (string-length str))
+                                       ;; last character of str is 's' or 'm'
+                                       ;; or 'h' or 'd'.
+                                       (member (string-take-right str 1)
+                                               (list "s" "m" "h" "d"))
+                                       ;; first part of str is an integer.
+                                       (integer?
+                                        (string->number
+                                         (string-take str
+                                                      (- (string-length str)
+                                                         1 ))))))
+                                var))
+                    var)
+                   (else
+                    ;; FIXME TODO I am getting a warning that says
+                    ;; possibly wrong number of arguments to `G_'
+                    ;; is one of the below lines to blame?
+                    (if (string? var)
+                        (report-error (G_ "(bounce \"~a\") is invalid.\n") var)
+                        (report-error (G_ "(bounce ~a) is invalid.\n") var))
+                    (display-hint (G_ "Try (bounce (list \"30m\" \"2h\"))\n"))
+                    (throw 'bad! var))))))
+  (cas opensmtpd-configuration-cas
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "cas"
+                                (list false? list-of-opensmtpd-ca?)))))
+
+  ;; list of many records of type opensmtpd-interface
+  (interfaces opensmtpd-configuration-interfaces
+              (default (list (opensmtpd-interface)))
+              (sanitize
+               (lambda (var)
+                 ;; This makes sure that no opensmtpd-interface is like this:
+                 ;; (opensmtpd-interface (senders #f) (masquerade #t)), which
+                 ;; is a syntax error.
+                 (define (correct-senders? interface)
+                   (not
+                    (and (not (opensmtpd-interface-senders interface))
+                         (opensmtpd-interface-masquerade interface))))
+
+                 (define fieldname "interface")
+
+                 ;; TODO rework this sanitize bit, so that if someone writes:
+                 ;; (opensmtpd-interface (senders #f) (masquerade #t)), they
+                 ;; get a proper error.
+                 ;; (report-error
+                 ;;  (G_ "((senders #f) & (masquerade #t)) is invalid.\n"))
+                 (if (and (list-of-interface? var)
+                          (every correct-senders? var)
+                          (not (contains-duplicate? var)))
+                     var
+                     (begin
+                       (display "<opensmtpd-configuration> fieldname ")
+                       (display  "'interface' may be #f or a list of records")
+                       (display "\n of unique <opensmtpd-interface>.\n")
+                       (throw 'bad! var))))))
+  (socket opensmtpd-configuration-socket
+                    (default #f)
+                    (sanitize
+                     (lambda (var)
+                       (define fieldname "socket")
+                       (if (or (opensmtpd-socket? var)
+                               (false? var))
+                           var
+                           (begin
+                             (report-error (G_ "(~a \"~a\") is invalid.~%")
+                                           fieldname var)
+                             (display-hint
+                              (G_
+                               (string-append "Try an ("
+                                              fieldname
+                                              " (opensmtpd-socket ...)) .\n")))
+                             (throw 'bad! var))))))
+  ;; list of strings of absolute path names
+  (includes opensmtpd-configuration-includes
+            (default #f)
+            (sanitize (lambda (var)
+                        (my/sanitize var "opensmtpd-configuration" "includes"
+                                     (list false? list-of-strings? gexp?)))))
+  (matches opensmtpd-configuration-matches
+           (default (list (opensmtpd-match
+                           (action (opensmtpd-local-delivery
+                                    (name "local")
+                                    (method "mbox")))
+                           (options (list
+                                     (opensmtpd-option
+                                      (option "for local")))))
+                          (opensmtpd-match
+                           (action (opensmtpd-relay
+                                    (name "outbound")))
+                           (options (list
+                                     (opensmtpd-option
+                                      (option "from local"))
+                                     (opensmtpd-option
+                                      (option "for any")))))))
+           ;; TODO perhaps I should sanitize this function like I sanitized
+           ;; the 'filters'. For example, you could have two different.
+           ;; actions, one for local delivery and one for remote,
+           ;; with the same name.
+           ;; It might be a bit complicated to do this.
+           ;; I might just let smtpd figure out if the user made a silly
+           ;; mistake by having two different actions with the same name.
+           (sanitize (lambda (var)
+                       var
+                       (my/sanitize var "opensmtpd-configuration" "matches"
+                                    (list list-of-opensmtpd-match?)))))
+  ;; list of many records of type mda-wrapper
+  ;; TODO/FIXME support using gexps here
+  ;; eg (list "name" gexp)
+  ;; TODO what are mda-wrappers for?  How do I use this fieldname?
+  ;; (mda-wrappers opensmtpd-configuration-mda-wrappers
+  ;;               (default #f)
+  ;;               (sanitize (lambda (var)
+  ;;                           (my/sanitize var
+  ;;                                        "opensmtpd-configuration"
+  ;;                                        "mda-wrappers"
+  ;;                                        (list false? string?)))))
+  (mta-max-deferred opensmtpd-configuration-mta-max-deferred
+                    (default 100)
+                    (sanitize (lambda (var)
+                                (my/sanitize var "opensmtpd-configuration"
+                                             "mta-max-deferred"
+                                             (list number?)))))
+  (queue opensmtpd-configuration-queue
+         (default #f)
+         (sanitize (lambda (var)
+                     (my/sanitize var "opensmtpd-configuration" "queue"
+                                  (list false? opensmtpd-queue?)))))
+  (smtp opensmtpd-configuration-smtp
+        (default #f)
+        (sanitize (lambda (var)
+                    (my/sanitize var "opensmtpd-configuration" "smtp"
+                                 (list false? opensmtpd-smtp?)))))
+  (srs opensmtpd-configuration-srs
+       (default #f)
+       (sanitize (lambda (var)
+                   (my/sanitize var "opensmtpd-configuration" "srs"
+                                (list false? opensmtpd-srs?)))))
   (setgid-commands? opensmtpd-setgid-commands? (default #t)))
 
+;; this help procedure is used 3 or 4 times by
+;; sanitize-options-for-opensmtpd-match
+(define* (throw-error-duplicate-option option error-arg
+                                       #:key (record-name "match"))
+  (throw-error error-arg
+               (list
+                (string-append "(opensmtpd-" record-name
+                               ") (options ...)) can only have one \n"
+                               "(opensmtpd-option (option \"" option
+                               "\")) record, but more are present. \n"))
+               #:duplicate-option #t))
+
+;; this procedure sanitizes the fieldname opensmtpd-match-options
+(define* (sanitize-options-for-opensmtpd-match %options)
+  (define option-list (list "for any" "for local" "for domain"
+                            "for rcpt-to" "from any" "from auth"
+                            "from local" "from mail-from" "from rdns"
+                            "from socket" "from src" "auth" "helo"
+                            "mail-from" "rcpt-to" "tag" "tls"))
+  (when (not (list-of-opensmtpd-option? %options))
+    (report-error (G_ ""))
+    (display
+     (string-append "(opensmtpd-match (options ...)) is a list of unique"
+                    " (opensmtpd-option ...) records.\nIt's value is: "))
+    (display %options)
+    (display "\n")
+    (throw 'bad! %options))
+
+  (let loop ((%traversing-options %options)
+             ;; sanitized-options is an alist that may end of looking
+             ;; like:
+             ;; (("for" (opensmtpd-option (option "for any")))
+             ;;  ("from" (opensmtpd-option (option "from any")))
+             ;;  ("tag (opensmtpd-option (option "tag") (data "tag")))
+             (%sanitized-options '())
+             (option-record (if (null? %options)
+                                '()
+                                (car %options)))
+             (option-string (if (null? %options)
+                                '()
+                                (opensmtpd-option-option
+                                 (car %options)))))
+
+    (cond
+     ((null? %traversing-options)
+      %options)
+     ;; error if option-string is invalid option
+     ((not (member option-string option-list))
+      (report-error (G_ "(opensmtpd-match \"~a\")) is invalid.\n")
+                    option-string)
+      (display-hint (G_ ""))
+      (display (hint-string option-string option-list #:fieldname "option"))
+      (throw 'bad! option-string))
+     ;; error, if duplicate option
+     ((assoc-ref %sanitized-options option-string)
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-match (options ...)) can "
+                              "only have one (opensmtpd-option (option "
+                              "\"" option-string "\")), but more "
+                              " \n are present.\n"))
+      (display-hint
+       (format #f (G_ "Try removing one (opensmtpd-option (option \"~a\")).~%")
+        option-string))
+      (throw 'bad! option-record))
+     ;; error, if duplicate from or duplicate for option
+     ((or
+       (if (and (string=? "for" (substring option-string 0 3))
+                (assoc-ref %sanitized-options "for"))
+           #t
+           #f)
+       (if (and (>= (length (string->list option-string)) 4)
+                (string=? "from" (substring option-string 0 4))
+                (assoc-ref %sanitized-options "from"))
+           #t
+           #f))
+      (throw-error %options
+                   (list "(opensmtpd-match (options ...)) can only have one"
+                         " (option \"for ...\") and one (option \"from ...\")"
+                         "\nBut (option \"" option-string "\") and (option \""
+                         (opensmtpd-option-option
+                          (if (assoc-ref %sanitized-options "for")
+                              (assoc-ref %sanitized-options "for")
+                              (assoc-ref %sanitized-options "from")))
+                         "\") are present.\n")
+                   #:hint-strings
+                   (list "Try removing one "
+                         (if (string=? "for" (substring option-string 0 3))
+                             "(opensmtpd-option (option \"for ...\"))"
+                             "(opensmtpd-option (option \"from ...\"))")
+                         " record.\n")))
+     ;; these 3 options must have fieldname data defined.
+     ((and (member option-string
+                   (list "helo" "mail-from" "rcpt-to"))
+           (not (opensmtpd-option-data option-record)))
+      (report-error (G_ ""))
+      (display (string-append "(option \"" option-string
+                              "\") must have (data ...) of type string or an "
+                              "(opensmtpd-table ...) record.\n"))
+      (throw 'bad! option-string))
+     ;; fieldname data must be a string.
+     ((and (string=? "tag" option-string)
+           (not (string? (opensmtpd-option-data option-record))))
+      (throw-error option-record
+                   (list "(opensmtpd-match ... (option \"tag\"))"
+                         " must have a 'data' of type string.\n")))
+     ((or (string=? "tls" option-string)
+          (string=? "for" (substring option-string 0 3))
+          (string=? "from" (substring option-string 0 4)))
+      ;; let's test the "for" and "from" options now.
+      (cond
+       ;; the options in this list cannot define 'data' or 'regex'
+       ;; fieldnames.
+       ((and (member option-string (list "for local" "for any"
+                                         "from any" "from local"
+                                         "from socket" "tls"))
+             (or (opensmtpd-option-data option-record)
+                 (opensmtpd-option-regex option-record)))
+        (report-error (G_ ""))
+        (display (string-append "When (openmstpd-option (option \""
+                                option-string "\") ...), "
+                                "then (data ...) and (regex ...) "
+                                "must be #f. \n"))
+        (throw 'bad! option-record))
+       ;; the options in this list must have a data field of type
+       ;; string or tables-data-are-a-list-of-strings?
+       ((and (member option-string
+                     (list "for domain" "for rcpt-to"
+                           "from mail-from" "from src"))
+             (or (false? (opensmtpd-option-data option-record))
+                 (tables-data-are-assoc-list?
+                  (opensmtpd-option-data option-record))))
+        (throw-error option-record
+                     (list "When (openmstpd-option (option \""
+                           option-string "\") ...) \n"
+                           "then (data ...) must be a string or an \n"
+                           "(opensmtpd-table ....) record whose "
+                           "'data' is a list of strings.\n")))
+       (else
+        (loop (cdr %traversing-options)
+              (alist-cons
+               (cond ((string=? "for" (substring option-string 0 3))
+                      "for")
+                     ((string=? "tls" option-string)
+                      "tls")
+                     (else "from"))
+               option-record
+               %sanitized-options)
+              ;;option-record
+              (if (null? (cdr %traversing-options))
+                  '()
+                  (car (cdr %traversing-options)))
+              ;; option-string
+              (if (null? (cdr %traversing-options))
+                  '()
+                  (opensmtpd-option-option
+                   (car (cdr %traversing-options))))))))
+     ;; TODO if auth's 'data' is an assoc-list table, then
+     ;; it IS invalid!
+     ;; option-string = 'auth' cannot be made invalidly,
+     ;; do not test for it.
+     (else
+      (loop (cdr %traversing-options)
+            (alist-cons option-string option-record
+                        %sanitized-options)
+            ;;option-record
+            (if (null? (cdr %traversing-options))
+                '()
+                (car (cdr %traversing-options)))
+            ;; option-string
+            (if (null? (cdr %traversing-options))
+                '()
+                (opensmtpd-option-option
+                 (car (cdr %traversing-options)))))))))
+
+(define (filter-phase-has-message-and-value? record)
+  (and (opensmtpd-filter-phase-message record)
+       (opensmtpd-filter-phase-value record)))
+
+;; return #t if phase needs a message. Or if the message did not start
+;; with a 4xx or 5xx status code. otherwise #f
+(define (filter-phase-decision-lacks-proper-message? record)
+  (define decision (opensmtpd-filter-phase-decision record))
+  (if (member decision (list "disconnect" "reject"))
+      ;; this message needs to be RFC compliant, meaning
+      ;; that it need to start with 4xx or 5xx status code
+      (cond ((eq? #f (opensmtpd-filter-phase-message record))
+             #t)
+            ((string? (opensmtpd-filter-phase-message record))
+             (let ((number (string->number
+                            (substring
+                             (opensmtpd-filter-phase-message record) 0 3))))
+               (if (and (number? number)
+                        (and (< number 600) (> number 399)))
+                   #f
+                   #t))))
+      #f))
+
+;; 'decision' "rewrite" requires 'value' to be a number.
+(define (filter-phase-lacks-proper-value? record)
+  (define decision (opensmtpd-filter-phase-decision record))
+  (if (string=? "rewrite" decision)
+      (if (and (number? (opensmtpd-filter-phase-value record))
+               (eq? #f (opensmtpd-filter-phase-message record)))
+          #f
+          #t)
+      #f))
+
+;; 'decision' "junk" or "bypass" cannot have a message or a value.
+(define (filter-phase-has-incorrect-junk-or-bypass? record)
+  (and
+   (member
+    (opensmtpd-filter-phase-decision record)
+    (list "junk" "bypass"))
+   (or
+    (opensmtpd-filter-phase-value record)
+    (opensmtpd-filter-phase-message record))))
+
+(define (filter-phase-junks-after-commit? record)
+  (and (string=? "junk" (opensmtpd-filter-phase-decision record))
+       (string=? "commit" (opensmtpd-filter-phase-phase record))))
+
+;; returns #t if list is a unique list of <opensmtpd-filter> or
+;; <opensmtpd-filter-phase> returns # otherwise
+;; only opensmtpd-filter-chain? uses this function, and opensmtpd-filter-chain
+;; is NEVER actually used.
+;; I could possibly remove it.
+(define (list-of-unique-filter-or-filter-phase? %filters)
+  (and (list? %filters)
+       (not (null? %filters))
+       ;; this list is made up of only <opensmtpd-filter-phase>
+       ;; or <opensmtpd-filter>
+       (every (lambda (filter)
+                (or (opensmtpd-filter? filter)
+                    (opensmtpd-filter-phase? filter)))
+              %filters)
+       ;; each filter-name is unique.
+       (not (duplicate-filter-name %filters))))
+
+(define (filters->list-of-filter-names %filters)
+  (map (lambda (filter)
+         (cond ((opensmtpd-filter-phase? filter)
+                (opensmtpd-filter-phase-name filter))
+               (else (opensmtpd-filter-name filter))))
+       %filters))
+
+(define (duplicate-string-in-list strings)
+  (define first-string (car strings))
+  (cond ((null? (cdr strings))
+         #f)
+        ((any (lambda (element)
+                (if (string=? element first-string)
+                    element
+                    #f))
+              (cdr strings))
+         first-string)
+        (else (duplicate-string-in-list (cdr strings)))))
+
+(define (duplicate-filter-name %filters)
+  (define filter-names (filters->list-of-filter-names %filters))
+  (duplicate-string-in-list filter-names))
+
+;; the sanitize procedures used for sanitizing each <opensmtpd-interface> and
+;; <opensmtpd-socket> fieldname 'filters'.
+;; It primarily sanitizes <filter-phases>.  The only sanitization it does
+;; for <filter>s, is no make sure there are no duplicate filter names.
+
+(define* (sanitize-socket-and-interfaces-filters
+          %filters
+          #:key (socket-or-interface "interface"))
+
+  ;; if there are two filters with the same name, store that name here.
+  (define the-duplicate-filter-name
+    (if (not %filters)
+        #f
+        (duplicate-filter-name %filters)))
+
+  (define %filter-phases
+    (if (not %filters)
+        '()
+        (remove opensmtpd-filter? %filters)))
+  ;; the order of the first two tests in this cond is important.
+  ;; (false?) has to be 1st and (duplicate-filter-filter-name) has to be
+  ;; second. You may optionally re-order the other alternates in the cond.
+  (cond ((false? %filters)
+         #f)
+        (the-duplicate-filter-name
+         (report-error (G_ ""))
+         (display (string-append
+                   "(opensmtpd-" socket-or-interface
+                   " (filters ...)) has a duplicate filter name: \""
+                   the-duplicate-filter-name "\".\n"))
+         (throw 'bad! %filters))
+        (else
+         (let loop ((%traversing-list %filter-phases)
+                    (fieldname (if (null? %filter-phases)
+                                   '()
+                                   (opensmtpd-filter-phase-decision
+                                    (car %filter-phases)))))
+           (cond
+            ((null? %traversing-list)
+             %filters)
+            ((opensmtpd-filter? (car %traversing-list))
+             (loop (cdr %traversing-list)
+                   (if (null? (cdr %traversing-list))
+                       '()
+                       (opensmtpd-filter-phase-decision
+                        (car (cdr %traversing-list))))))
+            ((filter-phase-has-message-and-value?
+              (car %traversing-list))
+             (report-error (G_ ""))
+             (display
+              (string-append "(opensmtpd-filter-phase ...) cannot define "
+                             "fieldnames 'value' \n and 'message'.\n")))
+            ((filter-phase-decision-lacks-proper-message?
+              (car %traversing-list))
+             (cond
+              ((string? fieldname)
+               (report-error
+                (G_ "(decision \"~a\") with (message ...) is invalid.~%")
+                fieldname))
+              ((or (integer? fieldname) (boolean? fieldname))
+               (report-error
+                (G_ "(decision ~a) with (message ...) is invalid.~%")
+                fieldname))
+              (else
+               (report-error
+                (G_ "(~a ...\") with (message ...) is invalid.~%... is ~a")
+                fieldname)))
+             (display-hint
+              (G_ (string-append "Try (opensmtpd-filter-phase "
+                                 "(message \"406 Not acceptable.\") "
+                                 "(decision \"" fieldname "\")).\n")))
+             (throw 'bad! (car %traversing-list)))
+            ((filter-phase-lacks-proper-value? (car %traversing-list))
+             (begin
+               (report-error (G_ ""))
+               (display
+                (string-append
+                 "(opensmtpd-filter-phase (decision \"rewrite\")"
+                 "\n\t\t(value ...)) must be a number.\n"))
+               (display-hint (G_ "Try (value 5)."))
+               (throw 'bad! (car %traversing-list))))
+            ((filter-phase-has-incorrect-junk-or-bypass?
+              (car %traversing-list))
+             (begin
+               (report-error (G_ ""))
+               (display
+                (string-append "(opensmtpd-filter-phase (decision \""
+                               (opensmtpd-filter-phase-decision
+                                (car %traversing-list))
+                               "\") cannot define (message ...) or "
+                               "(value ...).\n"))
+               (throw 'bad! (car %traversing-list))))
+            ((filter-phase-junks-after-commit? (car %traversing-list))
+             (begin
+               (report-error (G_ ""))
+               (display
+                (string-append
+                 "(opensmtpd-filter-phase (decision \"junk\")\n\t\t "
+                 "(phase \"commit\")) is invalid.\n"))
+               (display-hint
+                (G_ (string-append "You cannot junk an email during phase "
+                                   "\"commit\". Try (phase \"data\").\n")))
+               (throw 'bad! (car %traversing-list))))
+            (else (loop (cdr %traversing-list)
+                        (if (null? (cdr %traversing-list))
+                            '()
+                            (opensmtpd-filter-phase-decision
+                             (car (cdr %traversing-list)))))))))))
+
+(define* (sanitize-options-for-filter-phase %options)
+  (define option-list
+    (list "fcrdns" "rdns" "src" "helo" "auth" "mail-from" "rcpt-to"))
+  (let loop ((%traversing-options %options)
+             ;; sanitized-options is an alist that may end of looking like:
+             ;; (("fcrdns" (opensmtpd-option (option "fcrdns")))
+             ;;  ("auth" (opensmtpd-option (option "auth"))))
+             (%sanitized-options '())
+             (option-record (if (null? %options)
+                                '()
+                                (car %options)))
+             (option-string (if (null? %options)
+                                '()
+                                (opensmtpd-option-option (car %options)))))
+    (cond
+     ((null? %traversing-options)
+      %options)
+     ;; error if option-string is invalid option
+     ((not (member option-string option-list))
+      (report-error
+       (G_ "(opensmtpd-filter-phase (option \"~a\")) is invalid.\n")
+       option-string)
+      (display-hint (G_ ""))
+      (display (hint-string option-string option-list
+                            #:fieldname "option"))
+      (throw 'bad! option-string))
+
+     ;; if we see two "rdns" (for example), throw a
+     ;; "duplicate option" error.
+     ((assoc-ref %sanitized-options option-string)
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-filter-phase (options ...)) can "
+                              "only have one\n (opensmtpd-option (option \""
+                              option-string "\")), but more are present.\n"))
+      (display-hint
+       (format #f (G_ "Try removing one (option \"~a\").~%") option-string))
+      (throw 'bad! option-record))
+
+     ;; the next 4 options must have fieldname 'data' defined.
+     ((and (member option-string
+                   (list "src" "helo" "mail-from" "rcpt-to"))
+           (not (opensmtpd-table? (opensmtpd-option-data option-record))))
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-filter-phase ... " "(option \""
+                              option-string "\")) must define (data ...).\n"))
+      (display-hint (G_ "Try defining (data (opensmtpd-table ...).\n"))
+      (throw 'bad! option-record))
+     ;;fcrdns cannot have fieldname data defined
+     ((and (string=? "fcrdns" option-string)
+           (opensmtpd-option-data option-record))
+      (report-error (G_ ""))
+      (display (string-append "(opensmtpd-option \"" option-string "\") "
+                              "cannot define (data ...).\n"))
+      (display-hint (G_ ""))
+      (display "Try removing (data ...).\n")
+      (throw 'bad! option-record))
+     ;; rdns and auth cannot be made invalidly.
+     ;; skip testing them.
+     (else (loop (cdr %traversing-options)
+                 (alist-cons option-string option-record
+                             %sanitized-options)
+                 ;; option-record
+                 (if (null? (cdr %traversing-options))
+                     '()
+                     (car (cdr %traversing-options)))
+                 ;; option-string
+                 (if (null? (cdr %traversing-options))
+                     '()
+                     (opensmtpd-option-option
+                      (car (cdr %traversing-options)))))))))
+
+(define* (throw-error var %strings
+                      #:key
+                      (record-name #f)
+                      (duplicate-option #f)
+                      (fieldname #f)
+                      (hint-strings #f))
+  (cond ((and record-name fieldname)
+         (cond ((or (string? var))
+                (report-error (G_ "(~a \"~a\") is invalid.~%") fieldname var))
+               ((boolean? var)
+                (report-error (G_ "(~a ~a) is invalid.~%") fieldname var))
+               ((number? var)
+                (report-error (G_ "(~a ~a) is invalid.~%") fieldname
+                              (number->string var)))
+               (else
+                (report-error (G_ "(~a ...) is invalid.~%Its value is: ~a~%")
+                              fieldname var)))
+         (display-hint (G_ (string-append "(opensmtpd-" record-name
+                                          " (fieldname " fieldname "...)) "
+                                          (apply string-append %strings))))
+         (throw 'bad! var))
+        ((list? hint-strings)
+         (report-error (G_ ""))
+         (display (apply string-append %strings))
+         (display-hint (G_ (apply string-append hint-strings)))
+         (throw 'bad! var))
+        ;; display the output for throw-error-duplicate-option
+        (duplicate-option
+         (report-error (G_ ""))
+         (display (apply string-append %strings))
+         (display-hint
+          (format #f
+                  (G_ "Try removing one (opensmtpd-option \"~a\") option.\n")
+                               var))
+         (throw 'bad! var))
+        (else
+         (report-error (G_ ""))
+         (display (apply string-append %strings))
+         (throw 'bad! var))))
+
+;; if strings is (list "auth" "for any" "from local")
+;; Then this will return "Try \"auth\", \"for any\", or \"from local\".
+(define (try-string strings)
+  (string-append "Try "
+                 (let loop ((strings strings))
+                   (cond ((= 1 (length strings))
+                          (string-append
+                           "or \"" (car strings) "\".\n"))
+                         (else
+                          (string-append
+                           "\"" (car strings) "\", "
+                           (loop (cdr strings))))))))
+
+;; suppose string is "for anys"
+;; and strings is (list "for any" "for local" "for domain")
+;; then hint-string will return "Did you mean "for any"?"
+(define* (hint-string string strings
+                      #:key (fieldname #f))
+  (define str (string-closest string strings))
+  (if (not str)
+      (try-string strings)
+      (if fieldname
+          (string-append "Did you mean (" fieldname " \""
+                         str "\") ?\n")
+          (string-append "Did you mean  \"" str "\" ?\n"))))
+
+;; this is used for sanitizing <opensmtpd-filter-phase> fieldname 'options'
+(define (contains-duplicate? list)
+  (if (null? list)
+      #f
+      (or
+      ;; check if (car list) is in (cdr list)
+      (any (lambda (var)
+             (equal? var (car list)))
+           (cdr list))
+       ;; check if (cdr list) contains duplicate
+       (contains-duplicate? (cdr list)))))
+
+(define* (variable->string var #:key (append "") (postpend " "))
+  (let ((var (if (number? var)
+                 (number->string var)
+                 var)))
+    (if var
+        (string-append append var postpend)
+        "")))
+
+;;; Various functions to check that lists are of the appropriate type.
+
+;; given a list and procedure, this tests that each element of list is of type
+;; ie: (list-of-type? list string?) tests each list is of type string.
+(define (list-of-type? list proc?)
+  (if (and (list? list)
+           (not (null? list)))
+      (let loop ((list list))
+        (if (null? list)
+            #t
+            (if (proc? (car list))
+                (loop (cdr list))
+                #f)))
+      #f))
+
+(define (list-of-strings? list)
+  (list-of-type? list string?))
+
+(define (list-of-interface? list)
+  (list-of-type? list opensmtpd-interface?))
+
+(define (list-of-opensmtpd-option? list)
+  (list-of-type?
+   list opensmtpd-option?))
+
+(define (list-of-opensmtpd-ca? list)
+  (list-of-type? list opensmtpd-ca?))
+
+(define (list-of-opensmtpd-pki? list)
+  (list-of-type? list opensmtpd-pki?))
+
+(define (list-of-opensmtpd-match? list)
+  (list-of-type? list opensmtpd-match?))
+
+(define* (list-of-strings->string list
+                                  #:key
+                                  (string-delimiter ", ")
+                                  (postpend "")
+                                  (append "")
+                                  (drop-right-number 2))
+  (string-drop-right
+   (string-append (let loop ((list list))
+                    (if (null? list)
+                        ""
+                        (string-append append (car list) postpend
+                                       string-delimiter
+                                       (loop (cdr list)))))
+                  append)
+   drop-right-number))
+
+;; TODO I should probably change this to alist, because that's what this is.
+(define (assoc-list? assoc-list)
+  (list-of-type? assoc-list
+                 (lambda (pair)
+                   (and (pair? pair)
+                        (string? (car pair))
+                        (string? (cdr pair))
+                        (<= 1 (string-length (car pair)))
+                        (<= 1 (string-length (cdr pair)))))))
+
+(define (nested-list? list)
+  (every (lambda (element)
+           (and
+            (list-of-strings? element)
+            (< 1 (length element))))
+         list))
+
+;; this procedure takes in one argument.
+;; if that argument is an <opensmtpd-table> whose fieldname 'values' is
+;; an assoc-list, then it returns #t, #f if otherwise.
+(define (tables-data-are-assoc-list? table)
+  (if (not (opensmtpd-table? table))
+      #f
+      (assoc-list? (opensmtpd-table-data table))))
+
+;; this procedure takes in one argument
+;; if that argument is an <opensmtpd-table> whose fieldname 'values' is a
+;; list of strings, then it returns #t, #f if otherwise.
+(define (tables-data-are-a-list-of-strings? table)
+  (if (not (opensmtpd-table? table))
+      #f
+      (and (list-of-strings? (opensmtpd-table-data table)))))
+
+;; This procedures takes in an <opensmtpd-table>
+;; if that table a list of lists of strings eg:
+;; (list (list "cat") (list "dog"))
+;; then this returns #t, otherwise false.
+(define (tables-data-are-a-nested-list-of-strings? table)
+  (cond ((false? (opensmtpd-table-data table))
+         #f)
+        ((not (list? (opensmtpd-table-data table)))
+         #f)
+        (else
+         (nested-list? (opensmtpd-table-data table)))))
+
+;;; The following functions convert various records into strings.
+
+;; these next few functions help me to turn <table>s
+;; into strings suitable to fit into "opensmtpd.conf".
+(define (assoc-list->string assoc-list)
+  (string-drop-right
+   (let loop ((assoc-list assoc-list))
+     (if (null? assoc-list)
+         ""
+         ;; pair is (cons "hello" "world") -> ("hello" . "world")
+         (let ((pair (car assoc-list)))
+           (string-append
+            "\"" (car pair)  "\""
+            " = "
+            "\"" (cdr pair) "\""
+            ", "
+            (loop (cdr assoc-list))))))
+   2))
+
+;; can be of type: (quote list-of-strings) or (quote assoc-list)
+;;  this will output a string that looks like:
+;;  table <"mytable"> { "ludo"="ludo@gnu.org" }
+(define (opensmtpd-table->string table)
+  (string-append "table \"" (opensmtpd-table-name table) "\" "
+                 (cond ((tables-data-are-a-list-of-strings? table)
+                        (string-append "{ "
+                                       (list-of-strings->string
+                                        (opensmtpd-table-data table)
+                                        #:append "\""
+                                        #:drop-right-number 3
+                                        #:postpend "\"") " }"))
+                       ((tables-data-are-assoc-list? table)
+                        (string-append "{ "
+                                       (assoc-list->string
+                                        (opensmtpd-table-data table)) " }"))
+                       (else (throw 'youMessedUp table)))
+                 " \n"))
+
+;; will output something like:
+;; <"mytable">
+(define (opensmtpd-table-name->string table)
+  (string-append "<\"" (opensmtpd-table-name table) "\">"))
+
+(define (opensmtpd-interface->string record)
+  (string-append
+   "listen on "
+   (opensmtpd-interface-interface record) " "
+   (let* ((hostname (opensmtpd-interface-hostname record))
+          (hostnames (if (opensmtpd-interface-hostnames record)
+                         (opensmtpd-table-name
+                          (opensmtpd-interface-hostnames record))
+                         #f))
+          (filters (opensmtpd-interface-filters record))
+          (filter-name (if filters
+                           (if (< 1 (length filters))
+                               (generate-filter-chain-name filters)
+                               (if (opensmtpd-filter? (car filters))
+                                   (opensmtpd-filter-name (car filters))
+                                   (opensmtpd-filter-phase-name
+                                    (car filters))))
+                           #f))
+          (mask-src (opensmtpd-interface-mask-src record))
+          (tag (opensmtpd-interface-tag record))
+          (senders (opensmtpd-interface-senders record))
+          (masquerade (opensmtpd-interface-masquerade record))
+          (secure-connection (opensmtpd-interface-secure-connection record))
+          (port (opensmtpd-interface-port record))
+          (pki (opensmtpd-interface-pki record))
+          (auth (opensmtpd-interface-auth record))
+          (auth-optional (opensmtpd-interface-auth-optional record)))
+     (string-append
+      (if mask-src
+          (string-append "mask-src ")
+          "")
+      (variable->string hostname #:append "hostname ")
+      (variable->string hostnames #:append "hostnames <" #:postpend "> ")
+      (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+      (variable->string tag #:append "tag \"" #:postpend "\" ")
+      (if secure-connection
+          (cond ((string=? "smtps" secure-connection)
+                 "smtps ")
+                ((string=? "tls" secure-connection)
+                 "tls ")
+                ((string=? "tls-require" secure-connection)
+                 "tls-require ")
+                ((string=? "tls-require-verify" secure-connection)
+                 "tls-require verify "))
+          "")
+      (if senders
+          (string-append "senders <\"" (opensmtpd-table-name senders) "\"> "
+           (if masquerade
+               "masquerade "
+               ""))
+          "")
+      (variable->string port #:append "port " #:postpend " ")
+      (if pki
+          (variable->string (opensmtpd-pki-domain pki) #:append "pki ")
+          "")
+      (if auth
+          (string-append "auth "
+                         (if (opensmtpd-table? auth)
+                             (string-append
+                              (opensmtpd-table-name->string auth))
+                             ""))
+          "")
+      (if auth-optional
+          (string-append "auth-optional "
+                         (if (opensmtpd-table? auth-optional)
+                             (string-append
+                              "<\""
+                              (opensmtpd-table-name->string auth-optional)
+                              "\">")
+                             ""))
+          "")
+      "\n"))))
+
+(define (opensmtpd-socket->string record)
+  (string-append
+   "listen on socket "
+   (let* ((filters (opensmtpd-socket-filters record))
+          (filter-name (if filters
+                           (if (< 1 (length filters))
+                               (generate-filter-chain-name filters)
+                               (if (opensmtpd-filter? (car filters))
+                                   (opensmtpd-filter-name (car filters))
+                                   (opensmtpd-filter-phase-name
+                                    (car filters))))
+                           #f))
+          (mask-src (opensmtpd-socket-mask-src record))
+          (tag (opensmtpd-socket-tag record)))
+     (string-append
+      (if mask-src
+          (string-append "mask-src ")
+          "")
+      (variable->string filter-name #:append "filter \"" #:postpend "\" ")
+      (variable->string tag #:append "tag \"" #:postpend "\" ")
+      "\n"))))
+
+(define (opensmtpd-relay->string record)
+  (let ((backup (opensmtpd-relay-backup record))
+        (backup-mx (opensmtpd-relay-backup-mx record))
+        (helo (opensmtpd-relay-helo record))
+        ;; helo-src can either be a string IP address or an <opensmtpd-table>
+        (helo-src (if (opensmtpd-relay-helo-src record)
+                      (if (string? (opensmtpd-relay-helo-src record))
+                          (opensmtpd-relay-helo-src record)
+                          (string-append "<\""
+                                         (opensmtpd-table-name
+                                          (opensmtpd-relay-src record))
+                                         "\">"))
+                      #f))
+        (domain (if (opensmtpd-relay-domain record)
+                    (opensmtpd-table-name
+                     (opensmtpd-relay-domain record))
+                    #f))
+        (host (opensmtpd-relay-host record))
+        (name (opensmtpd-relay-name record))
+        (pki (if (opensmtpd-relay-pki record)
+                 (opensmtpd-pki-domain (opensmtpd-relay-pki record))
+                 #f))
+        (srs (opensmtpd-relay-srs record))
+        (tls (opensmtpd-relay-tls record))
+        (auth (if (opensmtpd-relay-auth record)
+                  (opensmtpd-table-name
+                   (opensmtpd-relay-auth record))
+                  #f))
+        (mail-from (opensmtpd-relay-mail-from record))
+        ;; src can either be a string IP address or an <opensmtpd-table>
+        (src (if (opensmtpd-relay-src record)
+                 (if (string? (opensmtpd-relay-src record))
+                     (opensmtpd-relay-src record)
+                     (string-append "<\""
+                                    (opensmtpd-table-name
+                                     (opensmtpd-relay-src record))
+                                    "\">"))
+                 #f)))
+
+    (string-append
+     "\""
+     name
+     "\" " "relay "
+     ;;FIXME should I always quote the host fieldname?
+     ;; do I need to quote localhost via "localhost" ?
+     (variable->string host #:append "host \"" #:postpend "\" ")
+     (variable->string backup)
+     (variable->string backup-mx #:append "backup mx ")
+     (variable->string helo #:append "helo ")
+     (variable->string helo-src #:append "helo-src ")
+     (variable->string domain #:append "domain <\"" #:postpend "\"> ")
+     (variable->string host #:append "host ")
+     (variable->string pki #:append "pki ")
+     (variable->string srs)
+     (variable->string tls #:append "tls ")
+     (variable->string auth #:append "auth <\"" #:postpend "\"> ")
+     (variable->string mail-from #:append "mail-from ")
+     (variable->string src #:append "src ")
+     "\n")))
+
+(define (opensmtpd-lmtp->string record)
+  (string-append "lmtp "
+                 (opensmtpd-lmtp-destination record)
+                 (if (opensmtpd-lmtp-rcpt-to record)
+                     (begin
+                       " " (opensmtpd-lmtp-rcpt-to record))
+                     "")))
+
+(define (opensmtpd-mda->string record)
+  (string-append "mda "
+                 (opensmtpd-mda-command record) " "))
+
+(define (opensmtpd-maildir->string record)
+  (string-append "maildir "
+                 "\""
+                 (if (opensmtpd-maildir-pathname record)
+                     (opensmtpd-maildir-pathname record)
+                     "~/Maildir")
+                 "\""
+                 (if (opensmtpd-maildir-junk record)
+                     " junk "
+                     " ")))
+
+(define (opensmtpd-local-delivery->string record)
+  (let ((name (opensmtpd-local-delivery-name record))
+        (method (opensmtpd-local-delivery-method record))
+        (alias (if (opensmtpd-local-delivery-alias record)
+                   (opensmtpd-table-name
+                    (opensmtpd-local-delivery-alias record))
+                   #f))
+        (ttl (opensmtpd-local-delivery-ttl record))
+        (user (opensmtpd-local-delivery-user record))
+        (userbase (if (opensmtpd-local-delivery-userbase record)
+                      (opensmtpd-table-name
+                       (opensmtpd-local-delivery-userbase record))
+                      #f))
+        (virtual (if (opensmtpd-local-delivery-virtual record)
+                     (opensmtpd-table-name
+                      (opensmtpd-local-delivery-virtual record))
+                     #f))
+        (wrapper (opensmtpd-local-delivery-wrapper record)))
+    (string-append
+     "\"" name "\" "
+     (cond ((string? method)
+            (string-append method " "))
+           ((opensmtpd-mda? method)
+            (opensmtpd-mda->string method))
+           ((opensmtpd-lmtp? method)
+            (opensmtpd-lmtp->string method))
+           ((opensmtpd-maildir? method)
+            (opensmtpd-maildir->string method)))
+     ;; FIXME/TODO support specifying alias file:/path/to/alias-file  ?
+     ;; I do not think that is something that I can do...
+     (variable->string alias #:append "alias <\"" #:postpend "\"> ")
+     (variable->string ttl #:append "ttl ")
+     (variable->string user #:append "user ")
+     (variable->string userbase #:append "userbase <\"" #:postpend "\"> ")
+     (variable->string virtual #:append "virtual <\"" #:postpend "\"> ")
+     (variable->string wrapper #:append "wrapper "))))
+
+;; this function turns both opensmtpd-local-delivery and
+;; opensmtpd-relay into strings.
+(define (opensmtpd-action->string record)
+  (string-append "action "
+                 (cond ((opensmtpd-local-delivery? record)
+                        (opensmtpd-local-delivery->string record))
+                       ((opensmtpd-relay? record)
+                        (opensmtpd-relay->string record)))
+                 " \n"))
+
+;; this turns option records found in <opensmtpd-match> into strings.
+(define* (opensmtpd-option->string record
+                                                 #:key
+                                                 (space-after-! #f))
+  (let ((bool (opensmtpd-option-bool record))
+        (option (opensmtpd-option-option record))
+        (regex (opensmtpd-option-regex record))
+        (data (opensmtpd-option-data record)))
+    (string-append
+     (if (false? bool)
+         (if space-after-!
+             "! "
+             "!")
+         "")
+     option " "
+     (if regex
+         "regex "
+         "")
+     (if data
+         (if (opensmtpd-table? data)
+             (string-append
+              (opensmtpd-table-name->string data) " ")
+             (string-append data " "))
+         ""))))
+
+(define (opensmtpd-match->string record)
+  (string-append "match "
+                 (let* ((action (opensmtpd-match-action record))
+                        (name (cond ((opensmtpd-relay? action)
+                                     (opensmtpd-relay-name action))
+                                    ((opensmtpd-local-delivery? action)
+                                     (opensmtpd-local-delivery-name action))
+                                    (else 'reject)))
+                        (options (opensmtpd-match-options record)))
+                   (string-append
+                    (if options
+                        (apply string-append
+                               (map opensmtpd-option->string options))
+                        "")
+                    (if (string? name)
+                        (string-append "action " "\"" name "\" ")
+                        "reject ")
+                    "\n"))))
+
+(define (opensmtpd-ca->string record)
+  (string-append "ca " (opensmtpd-ca-name record) " "
+                 "cert \"" (opensmtpd-ca-file record) "\"\n"))
+
+(define (opensmtpd-pki->string record)
+  (let ((domain (opensmtpd-pki-domain record))
+        (cert (opensmtpd-pki-cert record))
+        (key (opensmtpd-pki-key record))
+        (dhe (opensmtpd-pki-dhe record)))
+    (string-append "pki " domain " " "cert \"" cert "\" \n"
+                   "pki " domain " " "key \"" key "\" \n"
+                   (if dhe
+                       (string-append
+                        "pki " domain " " "dhe " dhe "\n")
+                       ""))))
+
+(define (generate-filter-chain-name list-of-filters)
+  (string-drop-right (apply string-append
+                            (flatten
+                             (map (lambda (filter)
+                                    (list
+                                     (if (opensmtpd-filter? filter)
+                                         (opensmtpd-filter-name filter)
+                                         (opensmtpd-filter-phase-name filter))
+                                     "-"))
+                                  list-of-filters)))
+                     1))
+
+(define (opensmtpd-filter->list-of-strings-and-gexps record)
+  (list "filter "
+        "\"" (opensmtpd-filter-name record) "\" "
+        (if (opensmtpd-filter-exec record)
+            "proc-exec "
+            "proc ")
+        "\"" (opensmtpd-filter-proc record) "\""
+        "\n\n"))
+
+;; this procedure takes in a list of <opensmtpd-filter> and
+;; <opensmtpd-filter-phase>. It returns a string of the form:
+;; filter "uniqueName" chain chain { "filter-name", "filter-name2" [, ...]}
+(define (opensmtpd-filter-chain->string list-of-filters)
+  (string-append "filter \""
+                 (generate-filter-chain-name list-of-filters)
+                 "\" "
+                 "chain {"
+                 (string-drop-right
+                  (apply string-append
+                         (flatten
+                          (map (lambda (filter)
+                                 (list
+                                  "\""
+                                  (if (opensmtpd-filter? filter)
+                                      (opensmtpd-filter-name filter)
+                                      (opensmtpd-filter-phase-name filter))
+                                  "\", "))
+                               list-of-filters)))
+                  2)
+                 "}\n\n"))
+
+(define (opensmtpd-filter-phase->string record)
+  (let ((name (opensmtpd-filter-phase-name record))
+        (phase (opensmtpd-filter-phase-phase record))
+        (decision (opensmtpd-filter-phase-decision record))
+        (options (opensmtpd-filter-phase-options record))
+        (message (opensmtpd-filter-phase-message record))
+        (value (opensmtpd-filter-phase-value record)))
+    (string-append "filter "
+                   "\"" name "\" "
+                   "phase " phase " "
+                   "match "
+                   (apply string-append ; turn the options into a string
+                          (flatten
+                           (map (lambda (option)
+                                  (opensmtpd-option->string
+                                   option #:space-after-! #f))
+                                options)))
+                   " "
+                   decision " "
+                   (if (member decision (list "reject" "disconnect"))
+                       (string-append "\"" message "\"")
+                       "")
+                   (if (string=? "rewrite" decision)
+                       (string-append "rewrite " (number->string value))
+                       "")
+                   "\n\n")))
+
+;; in the next procedure, the variable 'filters' is a list of
+;; <opensmtpd-filter>, <opensmtpd-filter-phase>, and filter chains, which are
+;; lists that look like:
+;; (list (opensmtpd-filter ...) (opensmtpd-filter-phase ...)
+;;       (opensmtpd-filter-phase ...) (opensmtpd-filter ...))
+;; This function converts (get-opensmtpd-filters <opensmtpd-configuration>)
+;; to a string.
+;; Consider if a user passed in a valid <opensmtpd-configuration>,
+;; so that (get-opensmtpd-filters (opensmtpd-configuration)) returns
+;; (list (opensmtpd-filter
+;;         (name "rspamd")
+;;         (proc "rspamd"))
+;;       ;; this is a listen-on, with a filter-chain.
+;;       (list (opensmtpd-filter-phase
+;;               (name "dkimsign")
+;;               ...)
+;;               (opensmtpd-filter
+;;                 (name "rspamd")
+;;                 (proc "rspamd"))))
+;;
+;; (we will call the above list "total filters"):
+;; did you notice that filter "rspamd" is listed twice?  Once by itself, and
+;; once again in a filter chain. How do you make sure that it is NOT printed
+;; twice in smtpd.conf?
+;; 1st flatten "total filters", then remove its duplicates so that we
+;; may print the <opensmtpd-filter>s and <opensmtpd-filter-phase>s.
+;; 2nd now we go through "total filters", and we only print the filter-chains.
+(define (opensmtpd-filters->list-of-strings-and-gexps filters)
+  ;; first print the unique <opensmtpd-filter-phase>s and <opensmtpd-filter>s.
+  ;; then print the filter-chains.
+  ;; to do this: flatten filters, then remove duplicates.
+  (flatten
+   (list
+    ;; TODO for funsies, try to figure out how to list the filter-phases and
+    ;; filters in one go.  I tried it earlier, and it broke the service.
+    ;; Why?
+    ;;
+
+    ;; print the filter-phases
+    (apply string-append
+           (map (lambda (filter)
+                  (cond ((opensmtpd-filter-phase? filter)
+                         (opensmtpd-filter-phase->string filter))
+                        (else "")))
+                (delete-duplicates (flatten filters))))
+
+    ;; list the filters that may be gexps
+    (map (lambda (filter)
+           (cond ((opensmtpd-filter? filter)
+                  (opensmtpd-filter->list-of-strings-and-gexps filter))
+                 (else "")))
+         (delete-duplicates (flatten filters)))
+
+     ;; now we have to print the filter chains.
+    (apply string-append
+           (map (lambda (filter)
+                  (cond ((list? filter)
+                         (opensmtpd-filter-chain->string filter))
+                        (else            ; you are a <opensmtpd-filter>
+                         "")))
+                filters)))))
+
+(define (opensmtpd-configuration-includes->string string)
+  (string-append
+   "include \"" string "\"\n"))
+
+(define (opensmtpd-configuration-srs->string record)
+  (let ((key (opensmtpd-srs-key record))
+        (backup-key (opensmtpd-srs-backup-key record))
+        (ttl-delay (opensmtpd-srs-ttl-delay record)))
+    (string-append
+     (variable->string key #:append "srs key " #:postpend "\n")
+     (variable->string backup-key #:append "srs key backup " #:postpend "\n")
+     (variable->string ttl-delay #:append "srs ttl " #:postpend "\n")
+     "\n")))
+
+;; TODO make sure all options here work!  I just fixed limit-max-rcpt!
+(define (opensmtpd-smtp->string record)
+  (let ((ciphers (opensmtpd-smtp-ciphers record))
+        (limit-max-mails (opensmtpd-smtp-limit-max-mails record))
+        (limit-max-rcpt (opensmtpd-smtp-limit-max-rcpt record))
+        (max-message-size (opensmtpd-smtp-max-message-size record))
+        (sub-addr-delim (opensmtpd-smtp-sub-addr-delim record)))
+    (string-append
+     (variable->string ciphers #:append "smtp ciphers " #:postpend "\n")
+     (variable->string limit-max-mails
+                       #:append "smtp limit max-mails " #:postpend "\n")
+     (variable->string limit-max-rcpt
+                       #:append "smtp limit max-rcpt " #:postpend "\n")
+     (variable->string max-message-size
+                       #:append "smtp max-message-size " #:postpend "\n")
+     (variable->string sub-addr-delim
+                       #:append "smtp sub-addr-delim " #:postpend "\n")
+     "\n")))
+
+(define (opensmtpd-configuration-queue->string record)
+  (let ((compression (opensmtpd-queue-compression record))
+        (encryption (opensmtpd-queue-encryption record))
+        (ttl-delay (opensmtpd-queue-ttl-delay record)))
+    (string-append
+     (if compression
+         "queue compression\n"
+         "")
+     (if encryption
+         (string-append
+          "queue encryption "
+          (if (not (boolean? encryption))
+              encryption
+              "")
+          "\n")
+         "")
+     (if ttl-delay
+         (string-append "queue ttl" ttl-delay "\n")
+         ""))))
+
+;; build a list of <opensmtpd-action> from
+;; opensmtpd-configuration-matches, which is a list of <opensmtpd-match>.
+;; Each <opensmtpd-match> has a fieldname 'action', which accepts
+;; an <opensmtpd-action>.
+(define (get-opensmtpd-actions record)
+  (define opensmtpd-actions
+    (let loop ((list (opensmtpd-configuration-matches record)))
+      (if (null? list)
+          '()
+          (cons (opensmtpd-match-action (car list))
+                (loop (cdr list))))))
+  (delete-duplicates (append opensmtpd-actions)))
+
+;; build a list of opensmtpd-pkis from
+;; opensmtpd-configuration-interfaces and
+;; get-opensmtpd-actions
+(define (get-opensmtpd-pkis record)
+  ;; TODO/FIXME/maybe/wishlist could get-opensmtpd-actions -> NOT have an
+  ;; opensmtpd-relay?
+  ;; I think so.  And if it did NOT have a relay configuration, then
+  ;; action-pkis would be '() when it needs to be #f.  because if the
+  ;; opensmtpd-configuration has NO pkis, then this function will
+  ;; return '(), when it should return #f.  If it returns '(), then
+  ;; opensmtpd-configuration-fieldname->string will
+  ;; print the string "\n" instead of ""
+  (define action-pkis
+    (let loop1 ((list (get-opensmtpd-actions record)))
+      (if (null? list)
+          '()
+          (if (and (opensmtpd-relay? (car list))
+                   (opensmtpd-relay-pki (car list)))
+              (cons (opensmtpd-relay-pki (car list))
+                    (loop1 (cdr list)))
+              (loop1 (cdr list))))))
+  ;; FIXME/TODO/maybe/wishlist
+  ;; this could be #f aka left blank. aka there are no interface records
+  ;; with pkis. aka there are no lines in the configuration like:
+  ;; listen on eth0 tls pki smtp.gnucode.me
+  ;; in that case the smtpd.conf will have an extra "\n"
+  (define listen-on-pkis
+    (let loop2 ((list (opensmtpd-configuration-interfaces record)))
+      (if (null? list)
+          '()
+          (if (opensmtpd-interface-pki (car list))
+              (cons (opensmtpd-interface-pki (car list))
+                    (loop2 (cdr list)))
+              (loop2 (cdr list))))))
+  (delete-duplicates (append action-pkis listen-on-pkis)))
+
+;; takes in a <opensmtpd-configuration> and returns a list whose
+;; elements are <opensmtpd-filter>, <opensmtpd-filter-phase>,
+;; and a filter-chain.
+;; It returns a list of <opensmtpd-filter> and/or <opensmtpd-filter-phase>
+;; here's an example of what this procedure might return:
+;; (list (opensmtpd-filter...) (opensmtpd-filter-phase ...)
+;;       (openmstpd-filter ...) (opensmtpd-filter-phase ...)
+;;       ;; this next list is a filter-chain.
+;;       (list (opensmtpd-filter-phase ...) (opensmtpd-filter...)))
+;;
+;; This procedure handles filter chains a little odd.
+(define (get-opensmtpd-filters record)
+  (define socket-filters
+    (if (and (opensmtpd-configuration-socket record)
+             (opensmtpd-socket-filters
+              (opensmtpd-configuration-socket record)))
+        (opensmtpd-socket-filters (opensmtpd-configuration-socket record))
+        '()))
+  (define list-of-interfaces
+    (if (opensmtpd-configuration-interfaces record)
+        (opensmtpd-configuration-interfaces record)
+        '()))
+
+  (delete-duplicates
+   (append
+    (remove boolean?
+            (map-in-order
+             ;; get the filters found in the <listen-on-record>s
+             (lambda (interface-or-socket-record)
+               (if (and
+                    (opensmtpd-interface-filters interface-or-socket-record)
+                    (= 1 (length (opensmtpd-interface-filters
+                                  interface-or-socket-record))))
+                   ;; this next line returns an <opensmtpd-interface>
+                   (car (opensmtpd-interface-filters
+                         interface-or-socket-record))
+                   ;; this next line returns a filter chain.
+                   (opensmtpd-interface-filters interface-or-socket-record)))
+             list-of-interfaces))
+    socket-filters)))
+
+(define (flatten . lst)
+  "Return a list that recursively concatenates all sub-lists of LST."
+  (define (flatten1 head out)
+    (if (list? head)
+        (fold-right flatten1 out head)
+        (cons head out)))
+  (fold-right flatten1 '() lst))
+
+;; This function takes in a record, or list, or anything, and returns
+;; a list of <opensmtpd-table>s assuming the thing you passed into it had
+;; any <opensmtpd-table>s.
+;;
+;; is object record? call func on it's fieldnames
+;; is object list? loop through it's fieldnames calling func on it's records
+;; is object #f or string? or '()? -> #f
+(define (get-opensmtpd-tables value)
+  (delete-duplicates
+   (remove boolean?
+           (flatten ;; turn (list '(1) '(2 '(3))) -> '(1 2 3)
+            (cond ((opensmtpd-table? value)
+                   value)
+                  ((record? value)
+                   (let* ((record-type (record-type-descriptor value))
+                          (list-of-record-fieldnames
+                           (record-type-fields record-type)))
+                     (map (lambda (fieldname)
+                            (get-opensmtpd-tables
+                             ((record-accessor record-type fieldname)
+                              value)))
+                          list-of-record-fieldnames)))
+                  ((and (list? value) (not (null? value)))
+                   (map get-opensmtpd-tables value))
+                  (else #f))))))
+
+(define (opensmtpd-configuration-fieldname->string
+         record fieldname-accessor record->string)
+  (if (fieldname-accessor record)
+      (begin
+        (string-append
+         (list-of-records->string (fieldname-accessor record)
+                                  record->string) "\n"))
+      ""))
+
+(define (list-of-records->string list-of-records record->string)
+  (string-append
+   (cond ((not (list? list-of-records))
+          (record->string list-of-records))
+         (else
+          (let loop ((list list-of-records))
+            (if (null? list)
+                ""
+                (string-append
+                 (record->string (car list))
+                 (loop (cdr list)))))))))
+
+(define (opensmtpd-configuration->string record)
+  ;; should I use this named let, or should I give this a name, or
+  ;; not use it at all...
+  ;; eg:
+  ;; (write-all-fieldnames
+  ;;   (list (cons fieldname fieldname->string)
+  ;;         (cons fieldname2 fieldname->string)))
+  ;; (let loop ([list
+  ;;            (list
+  ;;              (cons opensmtpd-configuration-includes
+  ;;                    (lambda (string)
+  ;;                      (string-append
+  ;;                        "include \"" string "\"\n")))
+  ;;              (cons opensmtpd-configuration-smtp opensmtpd-smtp->string)
+  ;;              (cons opensmtpd-configuration-srs opensmtpd-srs->string))])
+  ;;   (if (null? list)
+  ;;       ""
+  ;;       (string-append
+  ;;         (opensmtpd-configuration-fieldname->string record
+  ;;          (caar list)
+  ;;          (cdar list))
+  ;;          (loop (cdr list)))))
+  (string-append
+   (opensmtpd-configuration-fieldname->string
+    record opensmtpd-configuration-bounce
+    (lambda (%bounce)
+      (if %bounce
+          (list-of-strings->string %bounce)
+          "")))
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-smtp
+                                              opensmtpd-smtp->string)
+   (opensmtpd-configuration-fieldname->string
+    record
+    opensmtpd-configuration-srs
+    opensmtpd-configuration-srs->string)
+   (opensmtpd-configuration-fieldname->string
+    record
+    opensmtpd-configuration-queue
+    opensmtpd-configuration-queue->string)
+   ;; write out the mta-max-deferred
+   (opensmtpd-configuration-fieldname->string
+    record opensmtpd-configuration-mta-max-deferred
+    (lambda (var)
+      (string-append "mta max-deferred "
+                     (number->string
+                      (opensmtpd-configuration-mta-max-deferred record))
+                     "\n")))
+   ;;write out all the tables
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-tables
+                                              opensmtpd-table->string)
+   ;; write out all the cas
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-cas
+                                              opensmtpd-ca->string)
+   ;; write out all the pkis
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-pkis
+                                              opensmtpd-pki->string)
+   ;; write all of the interface and socket records
+   (opensmtpd-configuration-fieldname->string
+    record
+    opensmtpd-configuration-interfaces
+    opensmtpd-interface->string)
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-socket
+                                              opensmtpd-socket->string)
+   ;; write all the actions
+   (opensmtpd-configuration-fieldname->string record get-opensmtpd-actions
+                                              opensmtpd-action->string)
+   ;; write all of the matches
+   (opensmtpd-configuration-fieldname->string record
+                                              opensmtpd-configuration-matches
+                                              opensmtpd-match->string)))
+
+;; FIXME/TODO should I use format here srfi-28 ?
+;; web.scm nginx does a (format #f "string" "another string")
+;; this could be a list like
+;; (list
+;;   (file-append opensmtpd-dkimsign "/libexec/filter")
+;;   "-d gnucode.me -s /path/to/selector.cert")
+;; Then opensmtpd-configuration->mixed-text-file could be rewritten to be
+;; something like
+;; (mixed-text-file
+;;   (eval `(string-append (opensmtpd-configuration-fieldname->string ...))
+;;   (gnu services mail)))
+(define (opensmtpd-configuration->mixed-text-file record)
+  (apply mixed-text-file "smtpd.conf"
+         (flatten (list
+                   ;; write out the includes
+                   (opensmtpd-configuration-fieldname->string
+                    record
+                    opensmtpd-configuration-includes
+                    opensmtpd-configuration-includes->string)
+                   ;; TODO should I change the below line of code into these
+                   ;; two lines of code?
+                   ;;(opensmtpd-configuration-fieldname->string
+                   ;;  record get-opensmtpd-filters-and-filter-phases
+                   ;;  opensmtpd-filter-and-filter-phase->string)
+                   ;;(opensmtpd-configuration-fieldname->string
+                   ;;  record get-opensmtpd-filter-chains
+                   ;;  opensmtpd-filter-chain->string)
+                   ;; write out all the filters
+                   (opensmtpd-filters->list-of-strings-and-gexps
+                    (get-opensmtpd-filters record))
+                   (opensmtpd-configuration->string record)))))
+
 (define %default-opensmtpd-config-file
   (plain-file "smtpd.conf" "
 listen on lo
@@ -1668,18 +4140,37 @@ (define %default-opensmtpd-config-file
 match from local for any action outbound
 "))
 
-(define opensmtpd-shepherd-service
-  (match-lambda
-    (($ <opensmtpd-configuration> package config-file)
-     (list (shepherd-service
+(define (opensmtpd-shepherd-service config)
+  (list (shepherd-service
             (provision '(smtpd))
             (requirement '(loopback))
             (documentation "Run the OpenSMTPD daemon.")
-            (start (let ((smtpd (file-append package "/sbin/smtpd")))
-                     #~(make-forkexec-constructor
-                        (list #$smtpd "-f" #$config-file)
-                        #:pid-file "/var/run/smtpd.pid")))
-            (stop #~(make-kill-destructor)))))))
+            (start
+             (let ((smtpd (file-append
+                           (opensmtpd-configuration-package config)
+                           "/sbin/smtpd")))
+               #~(make-forkexec-constructor
+                  (list #$smtpd "-f"
+                        (or
+                         #$(opensmtpd-configuration-config-file config)
+                         #$(opensmtpd-configuration->mixed-text-file config)))
+                  #:pid-file "/var/run/smtpd.pid")))
+            (stop #~(make-kill-destructor)))))
+
+;; TODO why does the below NOT work?
+;(define (opensmtpd-shepherd-service config)
+;  (match-lambda
+;    (($ <opensmtpd-configuration> package config-file)
+;     (list (shepherd-service
+;            (provision '(smtpd))
+;            (requirement '(loopback))
+;            (documentation "Run the OpenSMTPD daemon.")
+;            (start (let ((smtpd (file-append package "/sbin/smtpd")))
+;                     #~(make-forkexec-constructor
+;                        (list #$smtpd "-f" (or #$config-file
+;                                               #$(opensmtpd-configuration->mixed-text-file config)))
+;                        #:pid-file "/var/run/smtpd.pid")))
+;            (stop #~(make-kill-destructor)))))))
 
 (define %opensmtpd-accounts
   (list (user-group
@@ -1700,10 +4191,10 @@ (define %opensmtpd-accounts
          (home-directory "/var/empty")
          (shell (file-append shadow "/sbin/nologin")))))
 
-(define opensmtpd-activation
-  (match-lambda
-    (($ <opensmtpd-configuration> package config-file)
-     (let ((smtpd (file-append package "/sbin/smtpd")))
+(define (opensmtpd-activation config)
+  (let ((smtpd (file-append (opensmtpd-configuration-package config) "/sbin/smtpd"))
+        (config-file (opensmtpd-configuration-config-file config))
+        (configuration (opensmtpd-configuration->mixed-text-file config)))
        #~(begin
            (use-modules (guix build utils))
            ;; Create mbox and spool directories.
@@ -1711,7 +4202,36 @@ (define opensmtpd-activation
            (mkdir-p "/var/spool/smtpd")
            (chmod "/var/spool/smtpd" #o711)
            (mkdir-p "/var/spool/mail")
-           (chmod "/var/spool/mail" #o711))))))
+           (chmod "/var/spool/mail" #o711)
+           (display (string-append "checking syntax of "
+                                   (or
+                                    #$config-file
+                                    #$configuration)
+                                   "\n"))
+           (system* #$smtpd "-nf"
+                    (or
+                     #$config-file
+                     #$configuration)))))
+
+;; TODO why does this not work?
+;(define (opensmtpd-activation config)
+;  (match-lambda
+;    (($ <opensmtpd-configuration> package config-file)
+;     (let ((smtpd (file-append package "/sbin/smtpd"))
+;           (configuration (opensmtpd-configuration->mixed-text-file config)))
+;       #~(begin
+;           (use-modules (guix build utils))
+           ;; Create mbox and spool directories.
+;           (mkdir-p "/var/mail")
+;          (mkdir-p "/var/spool/smtpd")
+;         (chmod "/var/spool/smtpd" #o711)
+;        (mkdir-p "/var/spool/mail")
+;           (chmod "/var/spool/mail" #o711)
+;           (display (string-append "checking syntax of "
+;                                  (or
+;                                    #$config-file
+;                                    #$configuration)
+;                                   "\n")))))))
 
 (define %opensmtpd-pam-services
   (list (unix-pam-service "smtpd")))
diff --git a/gnu/tests/mail.scm b/gnu/tests/mail.scm
index f13751b72f..f9bd96402b 100644
--- a/gnu/tests/mail.scm
+++ b/gnu/tests/mail.scm
@@ -37,6 +37,7 @@ (define-module (gnu tests mail)
   #:use-module (guix gexp)
   #:use-module (guix store)
   #:use-module (ice-9 ftw)
+  #:use-module (srfi srfi-64)
   #:export (%test-opensmtpd
             %test-exim
             %test-dovecot
@@ -165,6 +166,718 @@ (define %test-opensmtpd
    (description "Send an email to a running OpenSMTPD server.")
    (value (run-opensmtpd-test))))
 
+;; trying to create a bad record, should result in an error.
+;; this function should not be able return, instead it should throw an error
+;(define (create-bad-record record)
+  ;; TODO why is this not working
+;  (with-output-to-port (%make-void-port "w")
+;    (lambda () (when record #f))))
+
+;; if this caller function is reached, then trying to create the bad record
+;; resulted in an error.  So return true.
+(define (return-true error arg)
+  #t)
+
+(define (return-false error arg)
+  #f)
+
+(define (test-good-record func)
+  (catch #t func return-false))
+
+(define (run-opensmtpd-record-sanitation-test)
+  ;;(with-output-to-port (%make-void-port "w")
+  ;;  (lambda ()
+  (test-begin "run-opensmtpd-record-sanitation-test")
+
+  (test-error "(interface (filters ...)) has two filters with the same name."
+              #t
+              (let ((dkimsign
+                     (opensmtpd-filter
+                      (name "dkimsign")
+                      (exec #t)
+                      (proc
+                       (list
+                        (file-append
+                         opensmtpd-filter-dkimsign
+                         "/libexec/opensmtpd/filter-dkimsign")
+                             " -d gnucode.me -s 2021-09-22 -c "
+                             "relaxed/relaxed -k "
+                             "rando string"
+                             "/etc/dkim/private.key "
+                             "user nobody group nogroup")))))
+                (opensmtpd-interface
+                  (interface "lo")
+                  (filters (list
+                            dkimsign
+                            dkimsign)))))
+
+  ;; duplicate filter names.  The filters are different, the fix
+  ;; is to change one filter's 'name' field.
+  (test-error "Test <interface> cannot have two filters with the same name."
+              #t
+              (opensmtpd-interface
+               (filters (list
+                         (opensmtpd-filter-phase
+                          (name "src")
+                          (phase "connect")
+                          (options
+                           (list
+                            (opensmtpd-option
+                             (option "fcrdns")
+                             (bool #f))))
+                          (decision "junk"))
+                         (opensmtpd-filter-phase
+                          (name "src")
+                          (phase "helo")
+                          (options
+                           (list
+                            (opensmtpd-option
+                             (option "rdns")
+                             (bool #f))))
+                          (decision "reject")
+                          (message "433 no rdns."))))))
+
+  (test-error "(filter (proc ...)) is a list of strings or gexps, NOT numbers."
+              #t
+              (opensmtpd-filter
+               (name "dkimsign")
+               (proc
+                (list
+                 (file-append opensmtpd-filter-dkimsign
+                              "/libexec/opensmtpd/filter-dkimsign")
+                 " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                 5
+                 "/etc/dkim/private.key "
+                 "user nobody group nogroup"))
+               (exec #t)))
+
+  (test-error "Test <filter-phase> fieldname 'phase' has an wrong phase name."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "wrongString")
+               (decision "bypass")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "auth"))))))
+
+  (test-error
+   "(filter-phase (decision \"reject\")) requires a 'message'."
+   #t
+   (opensmtpd-interface
+    (filters (list
+              (opensmtpd-filter-phase
+               (name "src")
+               (phase "connect")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "src")
+                  (data (opensmtpd-table
+                         (name "src-table")
+                         (data (list "cat" "hat")))))))
+               (decision "reject"))))))
+
+  (test-error (string-append
+               "Test <filter-phase> fieldname 'decision' "
+               "w/ value \"reject\" and \"disconnect\" requires a 'message'."
+               " The message must begin with 4xx or 5xx.")
+    #t
+    (opensmtpd-interface
+     (filters (list
+               (opensmtpd-filter-phase
+                (name "src")
+                (phase "connect")
+                (options
+                 (list
+                  (opensmtpd-option
+                   (option "src")
+                   (data (opensmtpd-table
+                          (name "src-table")
+                          (data (list "cat" "hat")))))))
+                (decision "reject")
+                (message "322 Bad data!"))))))
+
+  (test-error
+   "(filter-phase \"rewrite\") requires fieldname 'value' to have a number."
+   #t
+   (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "noFRDNS")
+       (phase "commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns")
+                       (bool #f))))
+       (decision "rewrite"))))))
+
+  (define option-string1/2 (list-ref (list "junk" "bypass")
+                                     (random 2)))
+  (test-error
+   (string-append "(filter-phase \"decision\" with values 'junk' or 'bypass',"
+                  " then fieldname 'message' and 'value' must be blank.")
+              #t
+              (opensmtpd-interface
+               (filters
+                (list
+                 (opensmtpd-filter-phase
+                  (name "noFRDNS")
+                  (phase "commit")
+                  (options (list (opensmtpd-option
+                                  (option "fcrdns")
+                                  )))
+                  (decision option-string1/2)
+                  (message "This is not a good email."))))))
+
+  (test-error "You cannot junk an email on phase commit."
+              #t
+    (opensmtpd-interface
+    (filters
+     (list
+      (opensmtpd-filter-phase
+       (name "junk-after-commit")
+       (options (list (opensmtpd-option
+                       (option "fcrdns"))))
+       (phase "commit")
+       (decision "junk"))))))
+
+  (define (good-interface1)
+    (opensmtpd-interface
+     (senders
+      (opensmtpd-table
+       (name "senders")
+       (data '(("joshua" . "joshua@dismail.de")))))
+     (masquerade #t)))
+
+  (test-assert "good interface" (test-good-record good-interface1))
+
+  (test-error "Test <filter-phase> has 2 duplicate options."
+              #t
+              (opensmtpd-filter-phase
+               (name "invalid-fcrdns")
+               (phase "connect")
+               (options
+                (list (opensmtpd-option
+                       (option "fcrdns"))
+                      (opensmtpd-option
+                       (option "fcrdns"))))
+               (decision "reject")
+               (message "422 No valid fcrdns.")))
+
+  (test-error "Test <filter-phase> option 'src' requires a table."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "helo")
+               (decision "bypass")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "src"))))))
+
+  (test-error "Test <filter-phase> option 'fcrdns' cannot have a table."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "helo")
+               (decision "bypass")
+               (options
+                (list
+                 (opensmtpd-option
+                  (option "fcrdns")
+                  (data (opensmtpd-table
+                         (name "table")
+                         (data (list "hello" "cat")))))))))
+
+  (test-error "Test <filter-phase> must have at least one option."
+              #t
+              (opensmtpd-filter-phase
+               (name "filter")
+               (phase "helo")
+               (decision "bypass")))
+
+  (test-error
+   "(filter-phase (options ...)) must be a list of <opensmtpd-option>s."
+              #t
+              (opensmtpd-filter-phase
+               (name "rdns")
+               (decision "junk")
+               (phase "helo")
+               (options
+                (list 5))))
+
+  (test-error "Test (decision \"junks\") is invalid."
+              #t
+              (opensmtpd-filter-phase
+               (name "this")
+               (options (list
+                         (opensmtpd-option
+                          (option "auth"))))
+               (phase "helo")
+               (decision "junks")))
+
+  (test-error
+   (string-append
+    "(local-delivery (virtual ...) must be an <opensmtp-table> "
+    "whose 'data' is an alist.")
+              #t
+              (opensmtpd-local-delivery
+               (name "receive")
+               (method (opensmtpd-maildir
+                        (pathname "/home/%{rcpt.user}/Maildir")))
+               (virtual (opensmtpd-table
+                         (name "virt")
+                         (data (list "jbranso@dismail.de"))))))
+
+  (test-error "(opensmtpd-match (options ...)) should not be quoted."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options
+                '((opensmtpd-option
+                   (option "for any"))))))
+
+  (test-error "Test <opensmtpd-match> has duplicate 'for' options."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "for any"))
+                         (opensmtpd-option
+                          (option "for local"))))))
+
+  (test-error "Test <opensmtpd-match> has duplicate 'from' options."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "from any"))
+                         (opensmtpd-option
+                          (option "from auth"))))))
+
+  (define option-string1
+    (list-ref (list "helo" "rcpt-to" "mail-from")
+              (random 3)))
+  ;; rcpt-to, mail-from, and helo must have a data field.
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string1
+                             "\")) must also define fieldname 'data'.")
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option option-string1))))))
+  (define option-string2
+    (list-ref (list "for local" "for any" "from any"
+                    "from local" "from socket" "tls")
+              (random 6)))
+  ;; "for local" "for any" "from any" "from local" "from socket" "tls"
+  ;; cannot have data or regex defined
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string2
+                             "\")) cannot have fieldname 'data' defined.")
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option option-string2)
+                          (regex #t))))))
+
+  (test-error "(opensmtpd-match (action ...)) needs to be defined."
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (option "from auth"))))))
+
+  (test-error "(opensmtpd-match (options ...)) has duplicate 'helo's."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "helo")
+                          (bool #f))
+                         (opensmtpd-option
+                          (option "helo"))))))
+
+  (test-error "(opensmtpd-match (options ...)) has duplicate 'mail-from's."
+              #t
+              (opensmtpd-match
+               (action (opensmtpd-relay
+                        (name "relay")))
+               (options (list
+                         (opensmtpd-option
+                          (option "mail-from")
+                          (data "hello"))
+                         (opensmtpd-option
+                          (option "mail-from")
+                          (data "world"))))))
+
+  (test-error
+   "(opensmtpd-match (options ...)) has an invalid option name: fcrdns."
+   #t
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "fcrdns"))))
+    (action (opensmtpd-relay
+             (name "relay")))))
+
+  (test-error
+   "(opensmtpd-match (options ...)) has an invalid option name: rdns."
+   #t
+   (opensmtpd-match
+    (options (list
+              (opensmtpd-option
+               (option "rdns"))))
+    (action (opensmtpd-relay
+             (name "relay")))))
+
+  (test-error
+   (string-append
+    "(opensmtpd-match (options ...)) option-name 'tag' must "
+    "also have 'data' be a string.")
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (option "tag"))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+  (define option-string3
+    (list-ref (list "for domain" "for rcpt-to"
+                    "from mail-from" "from src")
+              (random 4)))
+  ;; the options in this list:
+  ;; (list "for domain" "for rcpt-to" "from mail-from" "from src")
+  ;; must have a data field.
+  (test-error
+   (string-append "Test (opensmtpd-option (option \""
+                  option-string3 "\"))"
+                  " must define fieldname 'data'.")
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (option option-string3))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+  (define option-string4
+    (list-ref (list "for local" "for any" "from any"
+                    "from local" "from socket" "tls")
+              (random 6)))
+  ;; the options in this list cannot have a data or regex field defined.
+  ;; (list "for local" "for any" "from any" "from local" "from socket" "tls")
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string4 "\"))"
+                             " cannot define fieldname 'data'.")
+              #t
+              (opensmtpd-match
+               (options (list
+                         (opensmtpd-option
+                          (regex #t)
+                          (option option-string4))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+
+  (define option-string5
+    (list-ref (list "for domain" "for rcpt-to"
+                    "from mail-from" "from src")
+              (random 4)))
+  (test-error (string-append "Test (opensmtpd-option (option \""
+                             option-string5 "\"))"
+                             " must define fieldname 'data' as a string or "
+                             "an <opensmtpd-table>, whose 'data' \n"
+                             "is a list of strings.")
+              #t
+              (opensmtpd-match
+               (options
+                (list (opensmtpd-option
+                       (option option-string5)
+                       (data (opensmtpd-table
+                              (name "src-table")
+                              (data '(("127.0.0.1" . "374.394.405.23"))))))))
+               (action (opensmtpd-relay
+                        (name "relay")))))
+
+  ;; match must have at least one option.
+  (test-error
+   "(opensmtpd-match (options ...)) must have at least one <opensmtpd-option>."
+   #t
+   (opensmtpd-match
+    (action
+     (opensmtpd-local-delivery
+      (name "mail")))))
+
+  ;; you cannot have strings of length 0.
+  (test-error
+   (string-append
+    "(opensmtpd-table (name \"table\") (data '((\"james\" . \"\")))) "
+    "has an empty string.")
+   #t
+   (opensmtpd-table
+    (name "mytable")
+    (data '(("hello" . "")))))
+
+  (define good-match1
+    (opensmtpd-match
+     (action (opensmtpd-relay
+              (name "relay")))
+     (options (list (opensmtpd-option
+                     (option "for any"))
+                    (opensmtpd-option
+                     (option "from any"))
+                    (opensmtpd-option
+                     (option "auth"))))))
+
+  (test-assert "good match" (test-good-record good-match1))
+  ;;(test-assert "Test <opensmtpd-match> is valid.")
+
+  ;; I used to have some code that assumed if you have
+  ;; an "<interface>" and an "<socket>" using the same filter, then that
+  ;; was a misconfiguration.  It's not.
+  (define (good-opensmtpd-configuration1)
+    (let ([interface "lo"]
+          [filter-dkimsign
+           (opensmtpd-filter
+            (name "dkimsign")
+            (exec #t)
+            (proc (list (file-append opensmtpd-filter-dkimsign
+                                     "/libexec/opensmtpd/filter-dkimsign")
+                        " -d gnucode.me -s 2021-09-22 -c relaxed/relaxed -k "
+                        "/etc/dkim/private.key "
+                        "user nobody group nogroup")))])
+      (opensmtpd-configuration
+       (interfaces
+        (list
+         ;; send out emails and be sure to dkimsign them.
+         (opensmtpd-interface
+          (interface interface)
+          (filters (list filter-dkimsign)))))
+       (socket
+        (opensmtpd-socket
+         (filters (list filter-dkimsign))))
+       (matches (list
+                 (opensmtpd-match
+                  (action (opensmtpd-relay
+                           (name "relay")))
+                  (options (list (opensmtpd-option
+                                  (option "for any"))
+                                 (opensmtpd-option
+                                  (option "from any"))
+                                 (opensmtpd-option
+                                  (option "auth"))))))))))
+
+  (test-assert
+      (string-append "opensmtpd-configuration may use the same dkimsign "
+                     "filter on <opensmtpd-socket> and <opensmtpd-interface>.")
+    (test-good-record good-opensmtpd-configuration1))
+
+  ;; this is just the largest configuration that I can test.
+  (define (good-opensmtpd-configuration2)
+    (let ([interface "lo"]
+          [creds-table
+           (opensmtpd-table
+            (name "creds")
+            (data
+             (list
+              (cons "joshua"
+                    "$6$Ec4m8FgKjT2F/03Y$k66ABdse9TzCX6qaALB3WBL9GC1rmAWJmaoSjFMpbhzat7DOpFqpnOwpbZ34wwsQYIK8RQlqwM1I/v6vsRq86."))))]
+          [receive-action
+           (opensmtpd-local-delivery
+                           (name "receive")
+                           (method (opensmtpd-maildir
+                                    (pathname "/home/%{rcpt.user}/Maildir")
+                                    (junk #t)))
+                           (alias (opensmtpd-table
+                                   (name "aliases")
+                                   (data '(("joshua@gnucode.me" . "joshua")))))
+                           (virtual (opensmtpd-table
+                                     (name "virt")
+                                     (data '(("josh"
+                                              . "jbranso@dismail.de"))))))]
+          ;; as of 7-24-22 this proc fieldname does not actually work, but
+          ;; is proper syntax.
+          [filter-dkimsign (opensmtpd-filter
+                            (name "dkimsign")
+                            (exec #t)
+                            (proc (list
+                                   (file-append
+                                    opensmtpd-filter-dkimsign
+                                    "/libexec/opensmtpd/filter-dkimsign")
+                                   " -d gnucode.me -s 2021-09-22 -c "
+                                   "relaxed/relaxed -k "
+                                   "/etc/dkim/private.key "
+                                   "user nobody group nogroup")))]
+          [filter-invalid-fcrdns (opensmtpd-filter-phase
+                                  (name "invalid-fcrdns")
+                                  (phase "connect")
+                                  (options
+                                   (list (opensmtpd-option
+                                          (option "fcrdns")
+                                          (bool #f))))
+                                  (decision "reject")
+                                  (message "422 No valid fcrdns."))]
+          [filter-invalid-rdns (opensmtpd-filter-phase
+                                (name "invalid-rdns")
+                                (phase "connect")
+                                (options
+                                 (list (opensmtpd-option
+                                        (option "rdns")
+                                        (bool #f))))
+                                (decision "junk"))]
+          [smtp.gnucode.me (opensmtpd-pki
+                            (domain "smtp.gnucode.me")
+                            (cert "guix.scm")
+                            (key "guix.scm"))])
+      (opensmtpd-configuration
+       (mta-max-deferred 50)
+       (queue
+        (opensmtpd-queue
+         (compression #t)))
+       (smtp
+        (opensmtpd-smtp
+         (max-message-size "10M")))
+       (srs
+        (opensmtpd-srs
+         (ttl-delay "5d")))
+       (interfaces
+        (list
+         (opensmtpd-interface
+          (interface interface)
+          (port 25)
+          (secure-connection "tls")
+          (filters (list filter-invalid-fcrdns
+                         filter-invalid-rdns))
+          (pki smtp.gnucode.me))
+         ;; this lets local users logged into the system via ssh send email
+         ;; be sure to dkimsign them.
+         (opensmtpd-interface
+          (interface interface)
+          (port 465)
+          (secure-connection "smtps")
+          (pki smtp.gnucode.me)
+          (auth creds-table)
+          (filters (list filter-dkimsign)))
+         ;; if you uncomment this next line, then you get issues.
+         ;;(opensmtpd-socket
+         ;; (filters (list filter-dkimsign)))
+         ;; send out emails and be sure to dkimsign them.
+         (opensmtpd-interface
+          (interface interface)
+          (port 587)
+          (secure-connection "tls-require")
+          (pki smtp.gnucode.me)
+          (auth creds-table)
+          (filters (list filter-dkimsign)))))
+       (socket
+        (opensmtpd-socket
+         (filters (list filter-dkimsign))
+         (tag "socket")))
+       (matches (list
+                 (opensmtpd-match
+                  (action (opensmtpd-relay
+                           (name "relay")))
+                  (options (list (opensmtpd-option
+                                  (option "for any"))
+                                 (opensmtpd-option
+                                  (option "from any"))
+                                 (opensmtpd-option
+                                  (option "auth")))))
+                 (opensmtpd-match
+                  (action receive-action)
+                  (options (list (opensmtpd-option
+                                  (option "from any"))
+                                 (opensmtpd-option
+                                  (option "for domain")
+                                  (data (opensmtpd-table
+                                         (name "domain-table")
+                                         (data (list "gnucode.me"
+                                                     "gnu-hurd.com"))))))))
+                 (opensmtpd-match
+                  (action receive-action)
+                  (options (list (opensmtpd-option
+                                  (option "for local"))))))))))
+
+  (test-assert "Test my largish example <opensmtpd-configuration>."
+    (test-good-record good-opensmtpd-configuration2))
+
+  ;; the matches have two actions with the same name,
+  ;; but are different actions.
+  (test-error
+   (string-append "Test <opensmtpd-configuration> fieldname 'matches' has "
+                  "two actions with the same name, but the actions are "
+                  "different.")
+   #t
+   (opensmtpd-configuration
+    (matches
+     (list (opensmtpd-match
+            (options
+             (list
+              (opensmtpd-option
+               (option "auth"))))
+            (action
+             (opensmtpd-local-delivery
+              (name "my-local-delivery")
+              (ttl "50m"))))
+           (opensmtpd-match
+            (options
+             (list
+              (opensmtpd-option
+               (option "auth"))))
+            (action
+             (opensmtpd-local-delivery
+              (name "my-local-delivery")
+              (ttl "50h"))))))))
+
+  ;; you can only have 1 opensmtpd-socket.
+  (test-error
+   (string-append
+    "(opensmtpd-configuration> (listen-on ...)) may only have "
+    "one <opensmtpd-socket>.")
+   #t
+   (let ([interface "lo"])
+     (opensmtpd-configuration
+      (socket
+       (list
+        (opensmtpd-socket)
+        (opensmtpd-socket)))
+      (matches (list
+                (opensmtpd-match
+                 (options
+                  (list
+                   (opensmtpd-option
+                    (option "auth"))))
+                 (action (opensmtpd-relay
+                          (name "relay")))))))))
+
+  (test-end "run-opensmtpd-record-sanitation-test"))
+
+(define %test-opensmtpd-record-sanitation
+  (system-test
+   (name "opensmtpdRecordSanitation")
+   (description
+    (string-append "<opensmtpd> has numerous sanity checks.\n"
+                   "This checks that invalid configurations, return an\n"
+                   "appropriate error.\n"))
+   (value (run-opensmtpd-record-sanitation-test))))
+
 
 (define %exim-os
   (simple-operating-system

base-commit: 4b3493ed0156709a924f31ef4c9a5efa0815dfe8
-- 
2.38.1





^ permalink raw reply related	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH opensmtpd-records v3] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-12-23 13:52     ` [bug#56046] [PATCH opensmtpd-records v3] " Joshua Branson via Guix-patches via
@ 2022-12-26 19:34       ` Liliana Marie Prikler
  2022-12-28  0:16         ` Joshua Branson via Guix-patches via
  0 siblings, 1 reply; 23+ messages in thread
From: Liliana Marie Prikler @ 2022-12-26 19:34 UTC (permalink / raw)
  To: Joshua Branson, 56046; +Cc: Joshua Branson

Am Freitag, dem 23.12.2022 um 08:52 -0500 schrieb Joshua Branson:
> 
> * gnu/services/mail.scm:
> (opensmtpd-table,
> opensmtpd-ca,
> opensmtpd-pki,
> opensmtpd-action-local-delivery,
> opensmtpd-maildir,
> opensmtpd-mda,
> opensmtpd-lmtp,
> opensmtpd-relay,
> opensmtpd-option,
> opensmtpd-filter-phase,
> opensmtpd-filter,
> opensmtpd-interface,
> opensmtpd-socket,
> opensmtpd-match,
> opensmtpd-smtp,
> opensmtpd-srs,
> opensmtpd-queue, and
> opensmtpd-configuration): New records.
Don't forget to put closing parentheses at the end of lines.  Also,
feel free to group them to save vertical space.

> (false?, is-value-right-type, add-comma-or-string,
> list-of-procedures->string, string-in-list?, my-sanitize,
> opensmtpd-filter-chain?, throw-error-duplicate-option,
> sanitize-list-of-options-for-match, sanitize-filters,
> list-has-duplicates-or-non-filters?,
> filter-phase-has-message-and-value?,
> filter-phase-decision-lacks-proper-message?,
> filter-phase-lacks-proper-value?,
> filter-phase-has-incorrect-junk-or-bypass?,
> filter-phase-junks-after-commit?,
> list-of-unique-filter-or-filter-phase?, throw-error,
> contains-duplicate?, list-of-type?, list-of-strings?,
> list-of-unique-opensmtpd-option?,
> list-of-opensmtpd-ca?,
> list-of-opensmtpd-pki?,
> list-of-opensmtpd-listen-on?,
> list-of-unique-opensmtpd-match?, list-of-strings->string,
> assoc-list? assoc-list, variable->string,
> tables-data-are-assoc-list?,
> tables-data-are-a-list-of-strings?,
> table-data-are-a-nested-list-of-strings?,
> assoc-list->string,
> opensmtpd-table->string,
> opensmtpd-listen-on->string,
> opensmtpd-listen-on-socket->string,
> opensmtpd-action-relay->string,
> opensmtpd-lmtp->string,
> opensmtpd-mda->string,
> opensmtpd-maildir->string,
> opensmtpd-action-local-delivery->string,
> opensmtpd-action->string, opensmtpd-option->string,
> opensmtpd-match->string,
> opensmtpd-ca->string, opensmtpd-pki->string,
> generate-filter-chain-name, opensmtpd-filter-chain->string,
> opensmtpd-filter-phase->string, opensmtpd-filters->string,
> opensmtpd-listen->string,
> opensmtpd-srs->string,
> opensmtpd-smtp->string,
> opensmtpd-queue->string, get-opensmtpd-actions,
> get-opensmtpd-pkis, get-opensmtpd-filters, flatten,
> get-opensmtpd-tables, opensmtpd-fieldname->string,
> list-of-records->string, opensmtpd->mixed-text-file): New
> procedures.
> 
> * gnu/tests/mail.scm : new tests for various opensmtpd records.
> 
> * doc/guix.texi (OpenSMTPD Service): Added documentation for the
> new records for opensmtpd.
> ---
>  doc/guix.texi         | 1065 ++++++++++++++++-
>  gnu/services/mail.scm | 2560
> ++++++++++++++++++++++++++++++++++++++++-
>  gnu/tests/mail.scm    |  713 ++++++++++++
>  3 files changed, 4310 insertions(+), 28 deletions(-)
> 
> diff --git a/doc/guix.texi b/doc/guix.texi
> index 535c8cdfc3..879a2ad233 100644
> --- a/doc/guix.texi
> +++ b/doc/guix.texi
> @@ -25407,16 +25407,66 @@ could instantiate a dovecot service like
> this:
>  @end lisp
>  
>  @subsubheading OpenSMTPD Service
> +@cindex opensmtpd
>  
>  @deffn {Scheme Variable} opensmtpd-service-type
> -This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
> -service, whose value should be an @code{opensmtpd-configuration}
> object
> -as in this example:
> +OpenSMTPD is an easy-to-use mail transfer agent (MTA).  OpenSMTPD
> +@strong{listens} for incoming mail and @strong{matches} the mail to
> +@strong{actions}. The following records represent those stages:
>  
> -@lisp
> -(service opensmtpd-service-type
> -         (opensmtpd-configuration
> -           (config-file (local-file "./my-smtpd.conf"))))
> +@multitable {aaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
I hope this will receive proper documentation.
> +@item @strong{listens}
> +@tab @code{<opensmtpd-interface>}
> +@item
> +@tab @code{<opensmtpd-socket>}
> +@item
> +@tab
> +@item @strong{matches}
> +@tab @code{<opensmtpd-match>}
> +@item
> +@tab
> +@item @strong{actions}
> +@tab @code{<opensmtpd-local-delivery>}
> +@item
> +@tab @code{<opensmtpd-relay>}
> +@end multitable
> +
> +Additionally, each @code{<opensmtpd-interface>} and
> +@code{<opensmtpd-socket>} may use a list of @code{<opensmtpd-
> filter>},
> +and/or @code{<opensmtpd-filter-phase>} records to filter
> +email/spam. Also numerous records' fieldnames use
> +@code{<opensmtpd-table>} records to hold lists or key value pairs of
> +data.  Be sure to read the @code{<opensmtpd-table>} section to learn
> the
> +differance between a @code{mapping table} and a @code{list table}.
> +
> +Finally, both @code{<opensmtpd-match>} and
> +@code{<opensmtpd-filter-phase>} use @code{<opensmtpd-option>} to
> +configure various options.
> +
> +A simple example opensmtpd configuration is below:
> +
> +@lisp
> +(let ((smtp.gnu.org (opensmtpd-pki
> +                        (domain "smtp.gnu.org")
> +                        (cert "file.cert")
> +                        (key "file.key"))))
> +  (service opensmtpd-service-type
> +           (opensmtpd-configuration
> +            (interfaces (list
> +                         (opensmtpd-interface
> +                          (pki smtp.gnu.org))
> +                         (opensmtpd-interface
> +                          (pki smtp.gnu.org)
> +                          (secure-connection "smtps"))))
> +            (matches (list
> +                      (opensmtpd-match
> +                       (action
> +                        (opensmtpd-local-delivery
> +                         (name "local-delivery"))))
> +                      (opensmtpd-match
> +                       (action
> +                        (opensmtpd-relay
> +                         (name "relay")))))))))
>  @end lisp
>  @end deffn
>  
> @@ -25425,7 +25475,7 @@ Data type representing the configuration of
> opensmtpd.
>  
>  @table @asis
>  @item @code{package} (default: @var{opensmtpd})
> -Package object of the OpenSMTPD SMTP server.
> +Package object of the OpenSMTPD server.
>  
>  @item @code{config-file} (default: @code{%default-opensmtpd-config-
> file})
>  File-like object of the OpenSMTPD configuration file to use.  By
> default
> @@ -25433,14 +25483,1013 @@ it listens on the loopback network
> interface, and allows for mail from
>  users and daemons on the local machine, as well as permitting email
> to
>  remote servers.  Run @command{man smtpd.conf} for more information.
>  
> +@item @code{bounce} (default: @code{(list "4h")})
> +@code{bounce} is a list of strings, which send warning messages to
> the
> +envelope sender when temporary delivery failures cause a message to
> +remain in the queue for longer than a specified delay. Each delay
> option
> +is a string parameter beginning with a positive decimal integer and
> a
> +unit, which can be 's', 'm', 'h', or 'd'. At most four delay
> parameters
> +can be specified.
> +
> +@item @code{interfaces} default:
> +@lisp
> +(list
> +  (opensmtpd-interface
> +    (interface "lo")
> +    (port 25)))
> +@end lisp
> +@code{interfaces} is a list of @code{<opensmtpd-interface>} records.
> +This list details what interfaces and ports OpenSMTPD listens on as
> well as
> +other options.
> +
> +@item @code{socket} (default: @code{(opensmtpd-socket)})
> +Listens for incoming connections on the Unix domain socket.
> +
> +@item @code{includes} (default: @code{#f})
> +@code{includes} is a list of string filenames. Each filename's
> contents is
> +additional configuration that is inserted into the top of the
> configuration
> +file.  Run @code{man smtpd.conf} for more information.
> +
> +@item @code{matches} default:
> +@lisp
> +(list (opensmtpd-match
> +       (action (opensmtpd-local-delivery
> +                (name "local")
> +                (method "mbox")
> +                (options
> +                 (list
> +                  (opensmtpd-option
> +                   (option "for local")))))))
> +      (opensmtpd-match
> +       (action (opensmtpd-relay
> +                (name "outbound")))
> +       (options
> +        (list
> +         (opensmtpd-option
> +          (option "from local"))
> +         (opensmtpd-option
> +          (option "for any"))))))
> +@end lisp
> +@code{matches} is a list of @code{<opensmtpd-match>} records, which
> +matches incoming mail and sends it to a correspending action. The
> match
> +records are evaluated sequentially, with the first match winning.
> +Therefore @emph{the order that you arrange your matches is
> important}.
> +It's a good idea to put specific matches first and an all
> emcompassing
> +match (like @code{(option "for any")}) @strong{last}. If an incoming
> +mail does not match any match records, then it is rejected.
> +
> +@item @code{mta-max-deferred} (default: @code{100})
> +When delivery to a given host is suspended due to temporary
> failures, cache
> +at most number envelopes for that host such that they can be
> delivered as
> +soon as another delivery succeeds to that host. The default is 100.
> +
> +@item @code{queue} (default: @code{#f})
> +@code{queue} expects an @code{<opensmtpd-queue>} record. With it,
> one may
> +compress and encrypt queue-ed emails as well as set the default
> expiration
> +time for temporarily undeliverable messages.
> +
> +@item @code{smtp} (default: @code{#f})
> +@code{smtp} expects an @code{<opensmtpd-smtp>} record, which lets
> one
> +specifiy how large email may be along with other settings.
> +
> +@item @code{srs} (default: @code{#f})
> +@code{srs} expects an @code{<opensmtpd-srs>} record, which lets one
> set
> +up SRS, the Sender Rewritting Scheme.
> +
>  @item @code{setgid-commands?} (default: @code{#t})
>  Make the following commands setgid to @code{smtpq} so they can be
>  executed: @command{smtpctl}, @command{sendmail}, @command{send-
> mail},
>  @command{makemap}, @command{mailq}, and @command{newaliases}.
>  @xref{Setuid Programs}, for more information on setgid programs.
> +
>  @end table
>  @end deftp
>  
> +@itemize
> +@item Data Type: opensmtpd-interface
> +Data type representing the configuration of an
> +@code{<opensmtpd-interface>}. It listens on the fieldname
> +@code{interface} for incoming connections, using the same syntax as
> +@code{ifconfig}. The interface parameter may also be an string
> interface
> +group, an string IP address, or a string domain name. Listening can
> +optionally be restricted to a specific address via the fieldname
> +@code{family}, which can be either @code{"inet4"} or @code{"inet6"}.
> +
> +@itemize
> +@item @code{interface} (default: @code{"lo"})
> +
> +The string interface to listen for incoming connections.  This
> string
> +may be an interface group, an IP address, or a domain name. These
> +interfaces can usually be found by the command @code{ip link}.
> +
> +@item @code{family} (default: @code{#f})
> +
> +Only listen on a specific address family.  Valid strings are
> +@code{"inet4"} or @code{"inet6"}, which will only listen on IPv4 or
> IPv6
> +respectfully.  If @code{(family #f)}, then opensmtpd will listen on
> both
> +IPv4 and IPv6.
> +
> +@item @code{auth} (default: @code{#f})
> +Support SMTPAUTH: clients may only start SMTP transactions after
> +successful authentication. If @code{auth} is @code{#t}, then users
> are
> +authenticated against their own normal login credentials.
> Alternatively
> +@code{auth} may be a @code{mapping table} that maps usernames to
> +encrypted passwords.  The password can be encrypted via the
> +@code{smtpctl} @code{encrypt} subcommand.
> +
> +@item @code{auth-optional} (default: @code{#f})
> +Support SMTPAUTH optionally: clients need not authenticate, but may
> do
> +so.  This allows the @code{<opensmtpd-interface>} to both accept
> +incoming mail from untrusted senders and permit outgoing mail from
> +authenticated users. It can be used in situations where it is not
> +possible to listen on a separate port (usually the submission port,
> 587)
> +for users to authenticate.  This option also accepts a @code{mapping
> +table} that maps usernames to encrypted passwords.
> +
> +@item @code{filters} (default: @code{#f})
> +A list of one or many @code{<opensmtpd-filter>} or
> +@code{<opensmtpd-filter-phase>} records. The filters are applied
> +sequentially. These records listen and filter on connections handled
> by this
> +listener.
> +
> +@item @code{hostname} (default: @code{#f})
> +Change the default server name in the greeting banner instead of the
> +default one.
> +
> +@item @code{hostnames} (default: @code{#f})
> +Override the server name for specific addresses. Use a @code{mapping
> +table} that maps string IP addresses to string hostnames. If the
> address
> +on which the connection arrives appears in the mapping, the
> associated
> +hostname is used.
> +
> +@item @code{mask-src} (default: @code{#f})
> +If @code{#t}, then omit the from part when prepending “Received”
> headers.
> +
> +@item @code{disable-dsn} (default: @code{#f})
> +When @code{#t}, then disable the DSN (Delivery Status Notification)
> extension.
> +
> +@item @code{pki} (default: @code{#f})
> +For secure connections, use an @code{<opensmtpd-pki>} record to
> prove a
> +mail server's identity.
> +
> +@item @code{port} (default: @code{25})
> +Listen on the integer port instead of the default port of 25.
> +
> +@item @code{proxy-v2} (default: @code{#f})
> +If @code{#t}, then support the PROXYv2 protocol, rewriting
> appropriately source
> +address received from proxy.
> +
> +@item @code{received-auth} (default: @code{#f})
> +If @code{#t}, then in “Received” headers, report whether the session
> was
> +authenticated and by which local user.
> +
> +@item @code{senders} (default: @code{#f})
> +Look up the authenticated user in the supplied @code{mapping table}
> to
> +find the email addresses that user is allowed to submit mail as.
> +
> +@item @code{masquerade} (default: @code{#f})
> +@code{masquerade}, is used in conjunction with @code{senders}.  If
> +@code{#t}, then the From header is rewritten to match the sender
> +provided in the SMTP session.  If @code{senders} is @code{#false},
> then
> +@code{masquerade} cannot be @code{#t}.
> +
> +@item @code{secure-connection} (default: @code{#f})
> +This is a string of one of these options:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
Same here
> +@item @code{"smtps"}
> +@tab Support SMTPS, by default on port 465.
> +@item @code{"tls"}
> +@tab Support STARTTLS, by default on port 25.
> +@item @code{"tls-require"}
> +@tab Like @code{"tls"}, but force clients to
> +@item
> +@tab establish a secure connection before being
> +@item
> +@tab allowed to start an SMTP transaction.
> +@item @code{"tls-require-verify"}
> +@tab Like @code{"tls-require"}, but clients must
> +@item
> +@tab also provide a valid certificate
> +@item
> +@tab to establish an SMTP session.
> +@end multitable
> +
> +@item @code{tag} (default: @code{#f})
> +Clients connecting to the listener are tagged with the given string
> tag.
> +@end itemize
> +
> +@item Data Type: opensmtpd-socket
> +Data type representing the configuration of an
> +@code{<opensmtpd-socket>}. Listen for incoming SMTP connections on
> the
> +Unix domain socket @samp{/var/run/smtpd.sock}. This is done by
> default,
> +even if the record is absent.
> +
> +@itemize
> +@item @code{filters} (default: @code{#f})
> +A list of one or many @code{<opensmtpd-filter>} or
> +@code{<opensmtpd-filter-phase>} records. These filter incoming
> +connections handled by this listener.
> +
> +@item @code{mask-src} (default: @code{#f})
> +If @code{#t}, then omit the from part when prepending “Received”
> headers.
> +
> +@item @code{tag} (default: @code{#f})
> +Clients connecting to the listener are tagged with the given string
> tag.
> +@end itemize
> +
> +@item Data Type: opensmtpd-match
> +@cindex opensmtpd-match
> +This data type represents the configuration of an
> +@code{<opensmtpd-match>} record.
> +
> +If at least one mail envelope matches the options of one match
> record,
> +receive the incoming message, put a copy into each matching
> envelope,
> +and atomically save the envelopes to the mail spool for later
> processing
> +by the respective @code{<opensmtpd-action>} found in fieldname
> +@code{action}.  Here is an example @code{opensmtpd-match}
> +record.
> +
> +@lisp
> +(opensmtpd-match
> + (action (opensmtpd-local-delivery
> +          (name "receive")
> +          (method (opensmtpd-maildir
> +                   (pathname "/home/%@{rcpt.user@}/Maildir")
> +                   (junk #t)))
> +          (virtual (opensmtpd-table
> +                    (name "virt")
> +                    (data '(("carmen" . "carmen@@gnu.org")))))))
> + (options (list (opensmtpd-option
> +                 (option "from any"))
> +                (opensmtpd-option
> +                 (option "for domain")
> +                 (data (opensmtpd-table
> +                        (name "domain-table")
> +                        (data (list "gnu.org" "fsf.org"))))))))
> +@end lisp
> +
> +@itemize
> +@item @code{action} (default: @code{#f})
> +
> +If mail matches this match configuration, then do this action. Valid
> values
> +include @code{<opensmtpd-local-delivery>} or
> +@code{<opensmtpd-relay>}.
> +
> +@item @code{options} (default: @code{#f})
> +The fieldname @code{option} is a list of unique
> +@code{<opensmtpd-option>} records.
> +
> +There are some mutually exclusive options: there can be only one
> ``for''
> +and only one ``from'' option.
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
and here.
> +@headitem for
> +@tab from
> +@item only use one of the following:
> +@tab only use one of the following:
> +@item @code{"for any"}
> +@tab @code{"from any"}
> +@item @code{"for local"}
> +@tab @code{"from auth"}
> +@item @code{"for domain"}
> +@tab @code{"from local"}
> +@item @code{"for rcpt-to"}
> +@tab @code{"from mail-from"}
> +@item
> +@tab @code{"from socket"}
> +@item
> +@tab @code{"from src"}
> +@end multitable
> +
> +Additionally, some options require additional data via
> +@code{<opensmtpd-option>}'s fieldname @code{data}.  The following
> list
> +will explain the below syntax.
> +
> +@itemize
> +@item @code{"for any"}
> +This option only requires fieldname @code{option} to have the string
> +@code{"for any"}:
> +
> +@lisp
> +      (opensmtpd-option
> +       (option "for any"))
> +@end lisp
> +
> +@item @code{"tag"} _tag_
> +This option only requires fieldname @code{option} to have the string
> +@code{"tag"} with a string in fieldname @code{data}:
> +
> +@lisp
> +      (opensmtpd-option
> +       (option "tag")
> +       (data "this-tag"))
> +@end lisp
> +
> +@item @code{"for rcpt"} _domain_ | <list table>
> +This option requires fieldname @code{data} to have a string domain
> or
> +@code{list table}:
> +
> +@lisp
> +      (opensmtpd-option
> +       (option "for rcpt")
> +       (data "gnu.org"))
> +@end lisp
> +
> +OR
> +
> +@lisp
> +      (opensmtpd-option
> +       (option "for rcpt")
> +       (data (list "gnu.org" "fsf.org")))
> +@end lisp
> +@end itemize
> +
> +The following matching options are supported and can all be negated
> (via not
> +#t). The options that support a table (anything surrounded with '<'
> and '>'
> +eg: <table>), also support specifying regex via (regex #t).
> +
> +@itemize
> +@item @code{"for any"}
> +Specify that session may address any destination.
> +
> +@item @code{"for local"}
> +Specify that session may address any local domain.  This is the
> default,
> +and may be omitted.
> +
> +@item @code{"for domain"} _domain_ | <domain>
> +Specify that session may address the string _domain_ or
> +@code{list table} <domain>.
> +
> +@item @code{"for rcpt-to"} _recipient_ | <recipient>
> +Specify that session may address the string _recipient_ or list
> table
> +<recipient>.
> +
> +@item @code{"from any"}
> +Specify that session may originate from any source.
> +
> +@item @code{"from auth"}
> +Specify that session may originate from any authenticated user, no
> matter
> +the source IP address.
> +
> +@item @code{"from auth"} _user_ | <user>
> +Specify that the session may originate from authenticated _user_ or
> +@code{list table} <user>, no matter the source IP address.
> +
> +@item @code{"from local"}
> +Specify that session may only originate from a local IP address, or
> from
> +the local enqueuer.  This is the default, and may be omitted.
> +
> +@item @code{"from mail-from"} _sender_ | <sender>
> +Specify that session may originate from _sender_ or @code{list
> table}
> +<sender>, no matter the source IP address.
> +
> +@item @code{"from rdns"}
> +Specify that session may only originate from an IP address that
> resolves
> +to a reverse DNS@.
> +
> +@item @samp{"from rdns"} _hostname_ | <hostname>
> +Specify that session may only originate from an IP address that
> resolves
> +to a reverse DNS matching string _hostname_ or @code{list table}
> +<hostname>.
> +
> +@item @samp{"from socket"}
> +Specify that session may only originate from the local enqueuer.
> +
> +@item @code{"from src"} _address_ | <address>
> +Specify that session may only originate from string _address_ or
> +@code{list table} <address> which can be a specific address or a
> subnet
> +expressed in CIDR-notation.
> +
> +@item @code{"auth"}
> +Matches transactions which have been authenticated.
> +
> +@item @code{"auth"} _username_ | <username>
> +Matches transactions which have been authenticated for string _user_
> or
> +@code{list table} <username>.
> +
> +@item @code{"helo"} _helo-name_ | <helo-name>
> +Specify that session's HELO / EHLO should match the string _helo-
> name_
> +or @code{list table} <helo-name>.
> +
> +@item @code{"mail-from"} _sender_ | <sender>
> +Specify that transactions's MAIL FROM should match the string
> _sender_
> +or @code{list table} <sender>.
> +
> +@item @code{"rcpt-to"} _recipient_ | <recipient>
> +Specify that transaction's RCPT TO should match the string
> _recipient_
> +or @code{list table} <recipient>.
> +
> +@item @code{"tag"} _tag_
> +Matches transactions tagged with the given tag.
> +
> +@item @code{"tls"}
> +Specify that transaction should take place in a TLS channel.
> +@end itemize
> +
> +@end itemize
> +
> +@item Data Type: opensmtpd-local-delivery
> +This data type represents the configuration of an
> +@code{<opensmtpd-local-delivery>} record.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +@code{name} is the string name of the relay action.
> +
> +@item @code{method} (default: @code{"mbox"})
> +The email delivery option.  Valid options are:
> +
> +@itemize
> +@item @code{"mbox"}
> +Deliver the message to the user's mbox with mail.local(8).
> +
> +@item @code{"expand-only"}
> +Only accept the message if a delivery method was specified in an
> aliases
> +or .forward file.
> +
> +@item @code{"forward-only"}
> +Only accept the message if the recipient results in a remote address
> after
> +the processing of aliases or forward file.
> +
> +@item @code{<opensmtpd-lmtp>}
> +Deliver the message to an LMTP server at @code{<opensmtpd-lmtp>}'s
> +fieldname @code{destination}. The location may be expressed as
> string
> +host:port or as a UNIX socket. Optionally, @code{<opensmtpd-lmtp>}'s
> +fieldname @code{rcpt-to} might be specified to use the recipient
> email
> +address (after expansion) instead of the local user in the LMTP
> session
> +as RCPT TO.
> +
> +@item @code{<opensmtpd-maildir>}
> +Deliver the message to the maildir in
> +@code{<opensmtpd-maildir>}'s fieldname @code{pathname} if specified,
> +or by default to @code{"~/Maildir"}.
> +
> +The pathname may contain format specifiers that are expanded before
> use
> +(see the below section about Format Specifiers).
> +
> +If @code{<opensmtpd-maildir>}'s record fieldname @code{junk} is
> @code{#t},
> +then message will be moved to the ‘Junk’ folder if it contains a
> positive
> +‘X-Spam’ header. This folder will be created under fieldname
> @code{pathname} if
> +it does not yet exist.
> +
> +@item @code{<opensmtpd-mda>}
> +Delegate the delivery to the @code{<opensmtpd-mda>}'s fieldname
> +@code{command} (type string) that receives the message on its
> standard input.
> +
> +The @code{command} may contain format specifiers that are expanded
> before use
> +(see Format Specifiers).
> +@end itemize
> +
> +@item @code{alias} (default: @code{#f})
> +Use the @code{mapping table} for aliases expansion.
> +
> +@item @code{ttl} (default: @code{#f})
> +@code{ttl} is a string specify how long a message may remain in the
> queue.  It's
> +format is @code{n@{s|m|h|d@}}.  eg: @code{"4m"} is four minutes.
> +
> +@item @code{user} (default: @code{#f} )
> +@code{user} is the string username for performing the delivery, to
> be looked up
> +with getpwnam(3).
> +
> +This is used for virtual hosting where a single username is in
> charge of
> +handling delivery for all virtual users.
> +
> +This option is not usable with the mbox delivery method.
> +
> +@item @code{userbase} (default: @code{#f})
> +@code{userbase} is an @code{<opensmtpd-table>} record for mapping
> user
> +lookups instead of the getpwnam(3) function.
> +
> +The fieldnames @code{user} and @code{userbase} are mutually
> exclusive.
> +
> +@item @code{virtual} (default: @code{#f})
> +@code{virtual} is an @code{<opensmtpd-table>} record is used for
> virtual
> +expansion.
> +@end itemize
> +
> +@item Data Type: opensmtpd-relay
> +This data type represents the configuration of an
> +@code{<opensmtpd-relay>} record.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +@code{name} is the string name of the relay action.
> +
> +@item @code{backup} (default: @code{#f})
> +When @code{#t}, operate as a backup mail exchanger delivering
> messages to any
> +mail exchanger with higher priority.
> +
> +@item @code{backup-mx} (default: @code{#f})
> +Operate as a backup mail exchanger delivering messages to any mail
> exchanger
> +with higher priority than mail exchanger identified as string name.
> +
> +@item @code{helo} (default: @code{#f})
> +Advertise string heloname as the hostname to other mail exchangers
> during
> +the HELO phase.
> +
> +@item @code{helo-src} (default: @code{#f} )
> + Use the mapping @code{<opensmtpd-table>} to look up a hostname
> +matching the source address, to advertise during the HELO phase.
> +
> +@item @code{domain} (default: @code{#f})
> +Do not perform MX lookups but look up destination domain in an
> +@code{<opensmtpd-table>} and use matching relay url as relay host.
> +
> +@item @code{host} (default: @code{#f})
> +Do not perform MX lookups but relay messages to the relay host
> described by
> +the string relay-url. The format for relay-url is
> +@samp{[proto://[label@@]]host[:port]}. The following protocols are
> available:
> +
> +@multitable {aaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.
> +@item @code{smtp}
> +@tab Normal SMTP session with opportunistic STARTTLS (the default).
> +@item @code{smtp+tls}
> +@tab Normal SMTP session with mandatory STARTTLS@.
> +@item @code{smtp+notls}
> +@tab Plain text SMTP session without TLS@.
> +@item @code{lmtp}
> +@tab LMTP session.  port is required.
> +@item @code{smtps}
> +@tab SMTP session with forced TLS on connection, default port is
> +@item
> +@tab 465.
> +@end multitable
> +
> +Unless noted, port defaults to 25.
> +
> +The label corresponds to an entry in a credentials table, as
> documented in
> +@code{man table}. It is used with the @code{"smtp+tls"} and
> @code{"smtps"} protocols for
> +authentication. Server certificates for those protocols are verified
> by
> +default.
> +
> +@item @code{pki} (default: @code{#f})
> +For secure connections, use the certificate associated with
> +@code{<opensmtpd-pki>} (declared in a pki directive) to prove the
> +client's identity to the remote mail server.
> +
> +@item @code{srs} (default: @code{#f})
> +If @code{#t}, then when relaying a mail resulting from a forward,
> use the Sender
> +Rewriting Scheme to rewrite sender address.
> +
> +@item @code{tls} (default: @code{#f}) boolean or string ``no-
> verify''
Instead of a string, take 'no-verify as symbol perhaps?
> +When @code{#t}, Require TLS to be used when relaying, using
> mandatory STARTTLS by
> +default. When used with a smarthost, the protocol must not be
> +@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not
> require a valid
> +certificate.
> +
> +@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table>}
> +Use the alist @code{<opensmtpd-table>} for connecting to relay-url
> +using credentials. This option is usable only with fieldname
> @code{host} option.
> +
> +@item @code{mail-from} (default: @code{#f}) string
> +Use the string mailaddress as MAIL FROM address within the SMTP
> transaction.
> +
> +@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-
> table>}
> +Use the string or @code{<opensmtpd-table>} sourceaddr for the
> +source IP address, which is useful on machines with multiple
> interfaces. If
> +the list contains more than one address, all of them are used in
> such a way
> +that traffic is routed as efficiently as possible.
> +@end itemize
> +
> +@item Data Type: opensmtpd-filter
> +This data type represents the configuration of an
> +@code{<opensmtpd-filter>}. This is the filter record one should use
> +if they want to use an external package to filter email eg: rspamd
> or
> +spamassassin.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +The string name of the filter.
> +
> +@item @code{proc} (default: @code{#f})
> +The string command or process name.  If @code{proc-exec} is
> @code{#t}, @code{proc} is
> +treated as a command to execute.  Otherwise, it is a process name.
> +
> +@item @code{proc-exec} (default: @code{#f})
> +If @code{#t}, then execute the command in @code{proc}.
> +@end itemize
> +
> +@item Data Type: opensmtpd-filter-phase
> +This data type represents the configuration of an
> +@code{<opensmtpd-filter-phase>}.
> +
> +In a regular workflow, @code{smtpd(8)} may accept or reject a
> message
> +based only on the content of envelopes. Its decisions are about the
> +handling of the message, not about the handling of an active
> session.
> +
> +Filtering extends the decision making process by allowing
> +@code{smtpd(8)} to stop at each phase of an SMTP session, check that
> +options are met, then decide if a session is allowed to move
> forward.
> +
> +With filtering via an @code{<opensmtpd-filter-phase>} record, a
> +session may be interrupted at any phase before an envelope is
> complete. A
> +message may also be rejected after being submitted, regardless of
> whether the
> +envelope was accepted or not.
> +
> +@itemize
> +@item @code{name} (default: @code{#f})
> +
> +The string name of the filter phase.
> +
> +@item @code{phase-name} (default: @code{#f})
> +The string name of the phase. Valid values are:
> +
> +@multitable {aaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @code{"connect"}
> +@tab upon connection, before a banner is displayed
> +@item @code{"helo"}
> +@tab after HELO command is submitted
> +@item @code{"ehlo"}
> +@tab after EHLO command is submitted
> +@item @code{"mail-from"}
> +@tab after MAIL FROM command is submitted
> +@item @code{"rcpt-to"}
> +@tab after RCPT TO command is submitted
> +@item @code{"data"}
> +@tab after DATA command is submitted
> +@item @code{"commit"}
> +@tab after message is fully is submitted
> +@end multitable
> +
> +@item @code{options} (default @code{#f})
> +A list of unique @code{<opensmtpd-option>} records.
> +
> +At each phase, various options, specified by a list of
> +@code{<opensmtpd-option>}, may be checked. The
> +@code{<opensmtpd-option>}'s fieldname @code{option} values of:
> +@code{"fcrdns"}, @code{"rdns"}, and @code{"src"} data are available
> in
> +all phases, but other data must have been already submitted before
> they
> +are available. Options with a @code{<table>} next to them require
> the
> +@code{<opensmtpd-option>}'s fieldname @code{data} to be an
> +@code{<opensmtpd-table>}. There are the available options:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @code{"fcrdns"}
> +@tab forward-confirmed reverse DNS is valid
> +@item @code{"rdns"}
> +@tab session has a reverse DNS
> +@item @code{"rdns"} <table>
> +@tab session has a reverse DNS in table
> +@item @code{"src"} <table>
> +@tab source address is in table
> +@item @code{"helo"} <table>
> +@tab helo name is in table
> +@item @code{"auth"}
> +@tab session is authenticated
> +@item @code{"auth"} <table>
> +@tab session username is in table
> +@item @code{"mail-from"} <table>
> +@tab sender address is in table
> +@item @code{"rcpt-to"} <table>
> +@tab recipient address is in table
> +@end multitable
> +
> +These conditions may all be negated by setting
> +@code{(opensmtpd-option (bool #f))}.
> +
> +Any conditions that require a table may indicate that tables include
> regexs
> +setting @code{(opensmtpd-option (regex #t))}.
> +
> +@item @code{decision}
> +A string decision to be taken. Some decisions require an
> @code{message}
> +or @code{value}.  The value and message may be put in the
> +@code{<opensmtpd-option>}'s fieldname @code{data}.  Valid strings
> are:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @code{"bypass"}
> +@tab the session or transaction bypasses filters
> +@item @code{"disconnect"} message
> +@tab the session is disconnected with message
> +@item @code{"junk"}
> +@tab the session or transaction is junked,
> +@item
> +@tab  i.e., an ‘X-Spam: yes’ header is added to
> +@item
> +@tab any messages
> +@item @code{"reject"} message
> +@tab the command is rejected with message
> +@item @code{"rewrite"} value
> +@tab the command parameter is rewritten with value
> +@end multitable
> +
> +Decisions that involve a message require that the message be RFC
> valid,
> +meaning that they should either start with a 4xx or 5xx status code.
> +Descisions can be taken at any phase, though junking can only happen
> before
> +a message is committed.
> +
> +@item @code{message} (default @code{#f})
> +A string message beginning with a 4xx or 5xx status code.
> +
> +@item @code{value} (default: @code{#f})
> +A number value.  @code{value} and @code{message} are mutually
> exclusive.
> +@end itemize
> +
> +@item Data Type: opensmtpd-option
> +This data type represents the configuration of an
> +@code{<opensmtpd-option>}, which is used by
> +@code{<opensmtpd-filter-phase>} and @code{<opensmtpd-match>}
> +to match various options for email.
> +
> +@itemize
> +@item @code{option} (default @code{#f}) string
> +
> +A string option to be taken. Some options require the fieldname
> +@code{data} to have a string or an @code{<opensmtpd-table>}. When
> the
> +option record is used inside of an @code{<opensmtpd-filter-phase>},
> then
> +valid strings for fieldname @code{option} are:
> +
> +@itemize
> +@item @code {"fcrdns"}
> +@item @code {"rdns"}
> +@item @code {"src"}
> +@item @code {"helo"}
> +@item @code {"auth"}
> +@item @code {"mail-from"}
> +@item @code {"rcpt-to"}
> +@end itemize
> +
> +When @code{<opensmtpd-option>} is used inside of an
> +@code{<opensmtpd-match>}, then valid strings for fieldname
> @code{option}
> +are:
> +
> +@itemize
> +@item @code {"for"}
> +@item @code {"for any"}
> +@item @code {"for local"}
> +@item @code {"for domain"}
> +@item @code {"for rcpt-to"}
> +@item @code {"from any"}
> +@item @code {"from auth"}
> +@item @code {"from local"}
> +@item @code {"from mail-from"}
> +@item @code {"from rdns"}
> +@item @code {"from socket"}
> +@item @code {"from src"}
> +@item @code {"auth"}
> +@item @code {"helo"}
> +@item @code {"mail-from"}
> +@item @code {"rcpt-to"}
> +@item @code {"tag"}
> +@item @code {"tls"}
> +@end itemize
> +
> +@item @code{data} (default @code{#f}) string | @code{<opensmtpd-
> table>}
> +Some options require a string or @code{<opensmtpd-table>} to be
> +present. One would specify that table here.
> +
> +@item @code{regex} (default: @code{#f}) boolean
> +Any options using a table may indicate that tables hold regular
> +expressions by setting this option to @code{#t}.
> +
> +@item @code{bool} (default: @code{#t}) boolean
> +When @code{(bool #f)}, this option record is negated.
> +@end itemize
> +
> +@item Data Type: opensmtpd-table
> +This data type represents the configuration of an
> +@code{<opensmtpd-table>}.
> +
> +@itemize
> +@item @code{name} (default @code{#f})
> +@code{name} is the name of the @code{<opensmtpd-table>} record.
> +
> +@item @code{data} (default: @code{#f}) string | list | alist |
> nested-list
> +@code{data} expects a string, a list of strings, an alist of
> strings, or
> +a nested list of strings.
> +eg:
> +
> +@itemize
> +
> +@item string
> +@lisp
> +(data "dev@@gnu.org")
> +@end lisp
> +
> +A table of this type is called a @code{string table}.
> +
> +@item list
> +@lisp
> +(data (list ("gnu.org" "fsf.org")))
> +@end lisp
> +
> +A table of this type is called a @code{list table}.
> +
> +@item alist
> +@lisp
> +(data '(("james" . "$encryptedPassword")
> +        ("jennifer" . "$encryptedPassword2)))
> +@end lisp
> +
> +A table of this type is called a @code{mapping table}.
> +
> +@item nested-list
> +@lisp
> +(data '(("user1" "root@@gnu.org" "admin@@gnu.org")
> +        ("user2" "james@@guix.gnu.org" "sarah@@fsf.org")))
> +@end lisp
> +
> +A table of this type is also called a @code{mapping table}.
> +
> +@end itemize
> +@end itemize
> +
> +@item Data Type: opensmtpd-pki
> +This data type represents the configuration of an
> +@code{<opensmtpd-pki>}.
> +
> +@itemize
> +@item @code{domain} (default @code{#f})
> +@code{domain} is the string name of the @code{<opensmtpd-pki>}
> record.
> +
> +@item @code{cert} (default: @code{#f})
> +@code{cert} (default: @code{#f})
> +
> +@code{cert} is the string certificate filename to use for this pki.
> +
> +@item @code{key} (default: @code{#f})
> +@code{key} is the string certificate falename to use for this pki.
> +
> +@item @code{dhe} (default: @code{"none"})
> +Specify the DHE string parameter to use for DHE cipher suites with
> host
> +pkiname. Valid parameter values are @code{"none"}, @code{"legacy"},
> or
> +@code{"auto"}. For @code{"legacy"}, a fixed key length of 1024 bits
> is
> +used, whereas for @code{"auto"}, the key length is determined
> +automatically. The default is @code{"none"}, which disables DHE
> cipher
> +suites.
> +@end itemize
> +
> +@item Data Type: opensmtpd-maildir
> +@itemize
> +@item @code{pathname} (default: @code{"~/Maildir"})
> +Deliver the message to the maildir if pathname if specified, or by
> default
> +to @code{"~/Maildir"}.
> +
> +The pathname may contain format specifiers that are expanded before
> use
> +(see FORMAT SPECIFIERS).
> +
> +@item @code{junk} (default: @code{#f})
> +If the junk argument is @code{#t}, then the message will be moved to
> the @samp{‘Junk’}
> +folder if it contains a positive @samp{‘X-Spam’} header. This folder
> will be
> +created under pathname if it does not yet exist.
> +@end itemize
> +
> +@item Data Type: opensmtpd-mda
> +This record lets you delegate the delivery to a command that
> receives
> +the message on its standard input.
> +
> +@itemize
> +@item @code{name}
> +The string name for this MDA command.
> +
> +@item @code{command}
> +The command to that delivers the mail.
> +
> +The command may contain format specifiers that are expanded before
> use (see
> +FORMAT SPECIFIERS).
> +@end itemize
> +
> +@item Data Type: opensmtpd-queue
> +@itemize
> +@item @code{compression} (default @code{#f})
> +Store queue files in a compressed format. This may be useful to save
> disk
> +space.
> +
> +@item @code{encryption} (default @code{#f})
> +Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If
> no key is specified, it is
> +read with getpass(3). If the string stdin or a single dash (‘-’) is
> given
> +instead of a key, the key is read from the standard input.
> +
> +@item @code{ttl-delay} (default @code{#f})
> +Set the default expiration time for temporarily undeliverable
> messages,
> +given as a positive decimal integer followed by a unit s, m, h, or
> d. The
> +default is four days (@code{"4d"}).
> +@end itemize
> +
> +@item Data Type: opensmtpd-smtp
> +Data type representing an @code{<opensmtpd-smtp>} record.
> +
> +@itemize
> +@item @code{ciphers} (default: @code{#f})
> +Set the control string for
> SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default
> is
> +         ``HIGH:!aNULL:!MD5''.
> +
> +@item @code{limit-max-mails} (default: @code{100})
> +Limit the number of messages to count for each sessio
> +
> +@item @code{limit-max-rcpt} (default: @code{1000})
> +Limit the number of recipients to count for each transaction.
> +
> +@item @code{max-message-size} (default: @code{35M})
> +Reject messages larger than size, given as a positive number of
> bytes or as
> +a string to be parsed with scan@math{_scaled}(3).
> +
> +@item @code{sub-addr-delim character} (default: @code{+})
> +When resolving the local part of a local email address, ignore the
> ASCII
> +character and all characters following it. This is helpful for email
> +filters. @samp{"admin+bills@@gnu.org"} is the same email address as
> +@samp{"admin@@gnu.org"}. BUT an email filter can filter emails
> addressed to first
> +email address into a 'Bills' email folder.
> +@end itemize
> +
> +@item Data Type: opensmtpd-srs
> +Use this record to set up the Sender Rewriting Scheme (SRS).
> +
> +@itemize
> +@item @code{key} (default: @code{#f})
> +Set the secret key to use for SRS, the Sender Rewriting Scheme.
> +
> +@item @code{backup-key} (default: @code{#f})
> +Set a backup secret key to use as a fallback for SRS@. This can be
> used to
> +implement SRS key rotation.
> +
> +@item @code{ttl-delay} (default: @code{"4d"})
> +Set the time-to-live delay for SRS envelopes. After this delay, a
> bounce
> +reply to the SRS address will be discarded to limit risks of forged
> +addresses.
> +@end itemize
> +
> +@item Format Specifiers
> +Some configuration records support expansion of their parameters at
> +runtime. Such records (for example
> +@code{<opensmtpd-maildir>}, @code{<opensmtpd-mda>}) may use
> +format specifiers which are expanded before delivery or relaying.
> The
> +following formats are currently supported:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{sender@}}
> +@tab sender email address, may be empty string
> +@item @samp{%@{sender.user@}}
> +@tab user part of the sender email address, may be empty
> +@item @samp{%@{sender.domain@}}
> +@tab domain part of the sender email address, may be empty
> +@item @samp{%@{rcpt@}}
> +@tab recipient email address
> +@item @samp{%@{rcpt.user@}}
> +@tab user part of the recipient email address
> +@item @samp{%@{rcpt.domain@}}
> +@tab domain part of the recipient email address
> +@item @samp{%@{dest@}}
> +@tab recipient email address after expansion
> +@item @samp{%@{dest.user@}}
> +@tab user part after expansion
> +@item @samp{%@{dest.domain@}}
> +@tab domain part after expansion
> +@item @samp{%@{user.username@}}
> +@tab local user
> +@item @samp{%@{user.directory@}}
> +@tab home directory of the local user
> +@item @samp{%@{mbox.from@}}
> +@tab name used in mbox From separator lines
> +@item @samp{%@{mda@}}
> +@tab mda command, only available for mda wrappers
> +@end multitable
> +
> +Expansion formats also support partial expansion using the optional
> bracket notations
> +with substring offset.  For example, with recipient domain
> @samp{“example.org”}:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{rcpt.domain[0]@}}
> +@tab expands to “e”
> +@item @samp{%@{rcpt.domain[1]@}}
> +@tab expands to “x”
> +@item @samp{%@{rcpt.domain[8:]@}}
> +@tab expands to “org”
> +@item @samp{%@{rcpt.domain[-3:]@}}
> +@tab expands to “org”
> +@item @samp{%@{rcpt.domain[0:6]@}}
> +@tab expands to “example”
> +@item @samp{%@{rcpt.domain[0:-4]@}}
> +@tab expands to “example”
> +@end multitable
> +
> +In addition, modifiers may be applied to the token.  For example,
> with recipient
> +@samp{“User+Tag@@Example.org”}:
> +
> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaa}
> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{rcpt:lowercase@}}
> +@tab expands to “user+tag@@example.org”
> +@item @samp{%@{rcpt:uppercase@}}
> +@tab expands to “USER+TAG@@EXAMPLE.ORG”
> +@item @samp{%@{rcpt:strip@}}
> +@tab expands to “User@@Example.org”
> +@item @samp{%@{rcpt:lowercasestrip@}}
> +@tab expands to “user@@example.org”
> +@end multitable
> +
> +For security concerns, expanded values are sanitized and potentially
> dangerous
> +characters are replaced with ‘:’. In situations where they are
> desirable, the
> +“raw” modifier may be applied. For example, with recipient
> +@samp{“user+t?g@@example.org”}:
> +
> +@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> +@item @samp{%@{rcpt@}}
> +@tab expands to “user+t:g@@example.org”
> +@item @samp{%@{rcpt:raw@}}
> +@tab expands to “user+t?g@@example.org”
> +@end multitable
> +@end itemize
> +
>  @subsubheading Exim Service
>  
>  @cindex mail transfer agent (MTA)
> diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
> index 43f144a42d..4175cab375 100644
> --- a/gnu/services/mail.scm
> +++ b/gnu/services/mail.scm
> @@ -35,6 +35,10 @@ (define-module (gnu services mail)
>    #:use-module (gnu packages admin)
>    #:use-module (gnu packages dav)
>    #:use-module (gnu packages tls)
> +  #:use-module (guix i18n)
> +  #:use-module (guix diagnostics)
> +  #:use-module (guix ui)
> +  #:use-module (guix utils)
>    #:use-module (guix records)
>    #:use-module (guix packages)
>    #:use-module (guix gexp)
> @@ -58,10 +62,149 @@ (define-module (gnu services mail)
>              mailbox-configuration
>              namespace-configuration
>  
> +            opensmtpd-table
> +            opensmtpd-table?
> +            opensmtpd-table-name
> +            opensmtpd-table-data
> +
> +            opensmtpd-ca
> +            opensmtpd-ca?
> +            opensmtpd-ca-name
> +            opensmtpd-ca-file
> +
> +            opensmtpd-pki
> +            opensmtpd-pki?
> +            opensmtpd-pki-domain
> +            opensmtpd-pki-cert
> +            opensmtpd-pki-key
> +            opensmtpd-pki-dhe
> +
> +            opensmtpd-local-delivery
> +            opensmtpd-local-delivery?
> +            opensmtpd-local-delivery-method
> +            opensmtpd-local-delivery-alias
> +            opensmtpd-local-delivery-ttl
> +            opensmtpd-local-delivery-user
> +            opensmtpd-local-delivery-userbase
> +            opensmtpd-local-delivery-virtual
> +            opensmtpd-local-delivery-wrapper
> +
> +            opensmtpd-maildir
> +            opensmtpd-maildir?
> +            opensmtpd-maildir-pathname
> +            opensmtpd-maildir-junk
> +
> +            opensmtpd-mda
> +            opensmtpd-mda-name
> +            opensmtpd-mda-command
> +
> +            opensmtpd-lmtp
> +            opensmtpd-lmtp-destination
> +            opensmtpd-lmtp-rcpt
> +
> +            opensmtpd-relay
> +            opensmtpd-relay?
> +            opensmtpd-relay-name
> +            opensmtpd-relay-backup
> +            opensmtpd-relay-backup-mx
> +            opensmtpd-relay-helo
> +            opensmtpd-relay-domain
> +            opensmtpd-relay-host
> +            opensmtpd-relay-pki
> +            opensmtpd-relay-srs
> +            opensmtpd-relay-tls
> +            opensmtpd-relay-auth
> +            opensmtpd-relay-mail-from
> +            opensmtpd-relay-src
> +
> +            opensmtpd-option
> +            opensmtpd-option?
> +            opensmtpd-option-option
> +            opensmtpd-option-bool
> +            opensmtpd-option-regex
> +            opensmtpd-option-data
> +
> +            opensmtpd-filter-phase
> +            opensmtpd-filter-phase?
> +            opensmtpd-filter-phase-name
> +            opensmtpd-filter-phase-phase
> +            opensmtpd-filter-phase-options
> +            opensmtpd-filter-phase-decision
> +            opensmtpd-filter-phase-message
> +            opensmtpd-filter-phase-value
> +
> +            opensmtpd-filter
> +            opensmtpd-filter?
> +            opensmtpd-filter-name
> +            opensmtpd-filter-proc
> +
> +            opensmtpd-interface
> +            opensmtpd-interface?
> +            opensmtpd-interface-interface
> +            opensmtpd-interface-family
> +            opensmtpd-interface-auth
> +            opensmtpd-interface-auth-optional
> +            opensmtpd-interface-filters
> +            opensmtpd-interface-hostname
> +            opensmtpd-interface-hostnames
> +            opensmtpd-interface-mask-src
> +            opensmtpd-interface-disable-dsn
> +            opensmtpd-interface-pki
> +            opensmtpd-interface-port
> +            opensmtpd-interface-proxy-v2
> +            opensmtpd-interface-received-auth
> +            opensmtpd-interface-senders
> +            opensmtpd-interface-masquerade
> +            opensmtpd-interface-secure-connection
> +            opensmtpd-interface-tag
> +
> +            opensmtpd-socket
> +            opensmtpd-socket?
> +            opensmtpd-socket-filters
> +            opensmtpd-socket-mask-src
> +            opensmtpd-socket-tag
> +
> +            opensmtpd-match
> +            opensmtpd-match?
> +            opensmtpd-match-action
> +            opensmtpd-match-options
> +
> +            opensmtpd-smtp
> +            opensmtpd-smtp?
> +            opensmtpd-smtp-ciphers
> +            opensmtpd-smtp-limit-max-mails
> +            opensmtpd-smtp-limit-max-rcpt
> +            opensmtpd-smtp-max-message-size
> +            opensmtpd-smtp-sub-addr-delim character
> +
> +            opensmtpd-srs
> +            opensmtpd-srs?
> +            opensmtpd-srs-key
> +            opensmtpd-srs-backup-key
> +            opensmtpd-srs-ttl-delay
> +
> +            opensmtpd-queue
> +            opensmtpd-queue?
> +            opensmtpd-queue-compression
> +            opensmtpd-queue-encryption
> +            opensmtpd-queue-ttl-delay
> +
>              opensmtpd-configuration
>              opensmtpd-configuration?
> +            opensmtpd-package
> +            opensmtpd-config-file
> +            opensmtpd-configuration-bounce
> +            opensmtpd-configuration-cas
> +            opensmtpd-configuration-interfaces
> +            opensmtpd-configuration-socket
> +            opensmtpd-configuration-includes
> +            opensmtpd-configuration-matches
> +            ;;opensmtpd-configuration-mda-wrappers
> +            opensmtpd-configuration-mta-max-deferred
> +            opensmtpd-configuration-srs
> +            opensmtpd-configuration-smtp
> +            opensmtpd-configuration-queue
>              opensmtpd-service-type
> -            %default-opensmtpd-config-file
>  
>              mail-aliases-service-type
>  
> @@ -1641,22 +1784,2351 @@ (define (generate-dovecot-documentation)
>         (listeners unix-listener-configuration fifo-listener-
> configuration
>                    inet-listener-configuration))
>        (protocol-configuration ,protocol-configuration-fields))
> -  'dovecot-configuration))
> +   'dovecot-configuration))
>  
>  \f
> -;;;
>  ;;; OpenSMTPD.
>  ;;;
> +;;; This next bit of code helps me create my own sanitizer
> functions.
> +
> +;; some fieldnames have a default value of #f, which is ok.  They
> cannot have
> +;; a value of #t.
> +;; for example opensmtpd-table-data can be #f, BUT NOT true.
> +;; my/sanitize procedure tests values to see if they are of the
> right kind.
> +;; procedure false? is needed to allow fields like 'values' to be
> blank,
> +;; (empty), or #f BUT also have a value like a list of strings.
Use less egocentric comments ;)

> +(define (false? var)
> +  (eq? #f var))
> +
> +;; TODO I have to have this procedure, or I need to change
> my/sanitize
> +;; procedure.
> +(define (my-file-exists? file)
> +  (and (string? file)
> +       (access? file F_OK)))
Does file-exists? not work for you?

> +;; This procedure takes in a var and a list of procedures.  It loops
> through
> +;; list of procedures passing in var to each.
> +;; if one procedure returns #t, the function returns true. 
> Otherwise #f.
> +;; TODO for fun rewrite this using map
> +;; If I rewrote it in map, then it may help with sanitizing.
> +;; eg: I could then potentially easily sanitize vars with lambda
> procedures.
> +(define (is-value-right-type? var list-of-procedures record
> fieldname)
> +  (if (null? list-of-procedures)
> +      #f
> +      (if ((car list-of-procedures) var)
> +          #t
> +          (is-value-right-type? var (cdr list-of-procedures) record
> +                                fieldname))))
Alternatively, (any (cut <> var) list-of-procedures).

> +;; converts strings like this:
> +;; "apple, ham, cherry" -> "apple, ham, or cherry"
> +;; "pineapple" -> "pinneapple".
> +;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
> +(define (add-comma-or string)
> +  (define last-comma-location (string-rindex string #\,))
> +  (if last-comma-location
> +      (if (string-contains string ", or" last-comma-location)
> +          string
> +          (string-replace string ", or" last-comma-location
> +                          (+ 1 last-comma-location)))
> +      string))
> +
> +
> +(define (list-of-procedures->string procedures)
> +  (define string
> +    (let loop ((procedures procedures))
> +      (if (null? procedures)
> +          ""
> +          (begin
> +            (string-append
> +             (cond ((eq? false? (car procedures))
> +                    "#f, ")
> +                   ((eq? boolean? (car procedures))
> +                    "a boolean, ")
> +                   ((eq? string? (car procedures))
> +                    "a string, ")
> +                   ((eq? integer? (car procedures))
> +                    "an integer, ")
> +                   ((eq? list-of-strings? (car procedures))
> +                    "a list of strings, ")
> +                   ((eq? assoc-list? (car procedures))
> +                    "an association list of strings, ")
> +                   ((eq? nested-list? (car procedures))
> +                    "a nested-list of strings, ")
> +                   ((eq? opensmtpd-pki? (car procedures))
> +                    "an <opensmtpd-pki> record, ")
> +                   ((eq? opensmtpd-table? (car procedures))
> +                    "an <opensmtpd-table> record, ")
> +                   ((eq? list-of-opensmtpd-match? (car procedures))
> +                    "a list of unique <opensmtpd-match> records, ")
> +                   ((eq? list-of-strings-or-gexps? (car procedures))
> +                    "a list of strings or gexps, ")
> +                   ;; TODO can I remove the next two procedures?
> +                   ;; tables-data-are-a* ?  I think I can.
> +                   ((eq? tables-data-are-assoc-list? (car
> procedures))
> +                    (string-append
> +                     "an <opensmtpd-table> record whose fieldname
> 'data' are "
> +                     "an assoc-list.\nFor example: (opensmtpd-table 
> "
> +                     "(name \"hostnames\") , "
> +                     "(data '((\"124.394.23.1\" . \"gnu.org\"))))"))
> +                   ((eq? tables-data-are-a-list-of-strings?
> +                         (car procedures))
> +                    (string-append
> +                     "on <opensmtpd-table> record whose fieldname
> 'data' is "
> +                     "a list of strings.\n"
> +                     "For example: (opensmtpd-table (name
> \"domains\") , "
> +                     "(data (list \"gnu.org\" \"guix.gnu.org\")))"))
> +                   ((eq? my-file-exists? (car procedures))
> +                    "a file, ")
> +                   (else "has an incorrect value, "))
> +             (loop (cdr procedures)))))))
> +  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
(define (procedure->string) ...)
(define (procedures->string list)
  (define strings (map procedure->string list))
  (string-append
   (string-join (drop-right strings 1) ", ")
   (if (> (length list) 1) ", or")
   (last strings)
   ".\n"))

> +(define (list-of-strings-or-gexps? list)
> +  (and (list? list)
> +       (cond ((null? list)
> +              #t)
> +             ((or (string? (car list))
> +                  (gexp? (car list))
> +                  (local-file? (car list))
> +                  (file-append? (car list))
> +                  (plain-file? (car list))
> +                  (computed-file? (car list))
> +                  (program-file? (car list)))
> +              (list-of-strings-or-gexps? (cdr list)))
> +             (else #f))))
> +
> +(define (my/sanitize var record fieldname list-of-procedures)
> +  (define try-string
> +    (string-append "Try " (list-of-procedures->string list-of-
> procedures)))
> +  (if (is-value-right-type? var list-of-procedures record fieldname)
> +      var
> +      (begin
> +        (cond ((string? var)
> +               (report-error (G_ "(~a \"~a\") is invalid.~%")
> fieldname var))
> +              ((or (number? var) (boolean? var))
> +              (report-error (G_ "(~a ~a) is invalid.~%") fieldname
> var) )
> +              (else
> +               (report-error (G_ "(~a ...) is invalid.~%Value is:
> ~a~%")
> +                             fieldname var)))
> +        (display-hint (G_ try-string))
> +        (throw 'bad! var))))
This procedure needs a proper name, like sanitize/check-type, but more
importantly, why not simply use define-configuration?


Cheers




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH opensmtpd-records v3] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-12-26 19:34       ` Liliana Marie Prikler
@ 2022-12-28  0:16         ` Joshua Branson via Guix-patches via
  2022-12-28 20:04           ` Liliana Marie Prikler
  2022-12-28 20:42           ` jbranso--- via Guix-patches via
  0 siblings, 2 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2022-12-28  0:16 UTC (permalink / raw)
  To: Liliana Marie Prikler; +Cc: Joshua Branson, 56046

Liliana Marie Prikler <liliana.prikler@gmail.com> writes:

> Am Freitag, dem 23.12.2022 um 08:52 -0500 schrieb Joshua Branson:
>> 
>> * gnu/services/mail.scm:
>> (opensmtpd-table,
>> opensmtpd-ca,
>> opensmtpd-pki,
>> opensmtpd-action-local-delivery,
>> opensmtpd-maildir,
>> opensmtpd-mda,
>> opensmtpd-lmtp,
>> opensmtpd-relay,
>> opensmtpd-option,
>> opensmtpd-filter-phase,
>> opensmtpd-filter,
>> opensmtpd-interface,
>> opensmtpd-socket,
>> opensmtpd-match,
>> opensmtpd-smtp,
>> opensmtpd-srs,
>> opensmtpd-queue, and
>> opensmtpd-configuration): New records.
> Don't forget to put closing parentheses at the end of lines.  Also,
> feel free to group them to save vertical space.

Thanks again for your speedy review! I am sending this from my gnucode.me email
address you'll notice. And it is using these new records. :)

>
>> (false?, is-value-right-type, add-comma-or-string,
>> list-of-procedures->string, string-in-list?, my-sanitize,
>> opensmtpd-filter-chain?, throw-error-duplicate-option,
>> sanitize-list-of-options-for-match, sanitize-filters,
>> list-has-duplicates-or-non-filters?,
>> filter-phase-has-message-and-value?,
>> filter-phase-decision-lacks-proper-message?,
>> filter-phase-lacks-proper-value?,
>> filter-phase-has-incorrect-junk-or-bypass?,
>> filter-phase-junks-after-commit?,
>> list-of-unique-filter-or-filter-phase?, throw-error,
>> contains-duplicate?, list-of-type?, list-of-strings?,
>> list-of-unique-opensmtpd-option?,
>> list-of-opensmtpd-ca?,
>> list-of-opensmtpd-pki?,
>> list-of-opensmtpd-listen-on?,
>> list-of-unique-opensmtpd-match?, list-of-strings->string,
>> assoc-list? assoc-list, variable->string,
>> tables-data-are-assoc-list?,
>> tables-data-are-a-list-of-strings?,
>> table-data-are-a-nested-list-of-strings?,
>> assoc-list->string,
>> opensmtpd-table->string,
>> opensmtpd-listen-on->string,
>> opensmtpd-listen-on-socket->string,
>> opensmtpd-action-relay->string,
>> opensmtpd-lmtp->string,
>> opensmtpd-mda->string,
>> opensmtpd-maildir->string,
>> opensmtpd-action-local-delivery->string,
>> opensmtpd-action->string, opensmtpd-option->string,
>> opensmtpd-match->string,
>> opensmtpd-ca->string, opensmtpd-pki->string,
>> generate-filter-chain-name, opensmtpd-filter-chain->string,
>> opensmtpd-filter-phase->string, opensmtpd-filters->string,
>> opensmtpd-listen->string,
>> opensmtpd-srs->string,
>> opensmtpd-smtp->string,
>> opensmtpd-queue->string, get-opensmtpd-actions,
>> get-opensmtpd-pkis, get-opensmtpd-filters, flatten,
>> get-opensmtpd-tables, opensmtpd-fieldname->string,
>> list-of-records->string, opensmtpd->mixed-text-file): New
>> procedures.
>> 
>> * gnu/tests/mail.scm : new tests for various opensmtpd records.
>> 
>> * doc/guix.texi (OpenSMTPD Service): Added documentation for the
>> new records for opensmtpd.
>> ---
>>  doc/guix.texi         | 1065 ++++++++++++++++-
>>  gnu/services/mail.scm | 2560
>> ++++++++++++++++++++++++++++++++++++++++-
>>  gnu/tests/mail.scm    |  713 ++++++++++++
>>  3 files changed, 4310 insertions(+), 28 deletions(-)
>> 
>> diff --git a/doc/guix.texi b/doc/guix.texi
>> index 535c8cdfc3..879a2ad233 100644
>> --- a/doc/guix.texi
>> +++ b/doc/guix.texi
>> @@ -25407,16 +25407,66 @@ could instantiate a dovecot service like
>> this:
>>  @end lisp
>>  
>>  @subsubheading OpenSMTPD Service
>> +@cindex opensmtpd
>>  
>>  @deffn {Scheme Variable} opensmtpd-service-type
>> -This is the type of the @uref{https://www.opensmtpd.org, OpenSMTPD}
>> -service, whose value should be an @code{opensmtpd-configuration}
>> object
>> -as in this example:
>> +OpenSMTPD is an easy-to-use mail transfer agent (MTA).  OpenSMTPD
>> +@strong{listens} for incoming mail and @strong{matches} the mail to
>> +@strong{actions}. The following records represent those stages:
>>  
>> -@lisp
>> -(service opensmtpd-service-type
>> -         (opensmtpd-configuration
>> -           (config-file (local-file "./my-smtpd.conf"))))
>> +@multitable {aaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> I hope this will receive proper documentation.

Users can still use

(service opensmtpd-service-type
         (opensmtpd-configuration
           (config-file (local-file "./my-smtpd.conf"))))

config-file is still a fieldname of <opensmtpd-configuration>.  Is that what you mean?

Also the generated documentation is available here:

https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd-records-documentation.txt

>> +@item @strong{listens}
>> +@tab @code{<opensmtpd-interface>}
>> +@item
>> +@tab @code{<opensmtpd-socket>}
>> +@item
>> +@tab
>> +@item @strong{matches}
>> +@tab @code{<opensmtpd-match>}
>> +@item
>> +@tab
>> +@item @strong{actions}
>> +@tab @code{<opensmtpd-local-delivery>}
>> +@item
>> +@tab @code{<opensmtpd-relay>}
>> +@end multitable
>> +
>> +Additionally, each @code{<opensmtpd-interface>} and
>> +@code{<opensmtpd-socket>} may use a list of @code{<opensmtpd-
>> filter>},
>> +and/or @code{<opensmtpd-filter-phase>} records to filter
>> +email/spam. Also numerous records' fieldnames use
>> +@code{<opensmtpd-table>} records to hold lists or key value pairs of
>> +data.  Be sure to read the @code{<opensmtpd-table>} section to learn
>> the
>> +differance between a @code{mapping table} and a @code{list table}.
>> +
>> +Finally, both @code{<opensmtpd-match>} and
>> +@code{<opensmtpd-filter-phase>} use @code{<opensmtpd-option>} to
>> +configure various options.
>> +
>> +A simple example opensmtpd configuration is below:
>> +
>> +@lisp
>> +(let ((smtp.gnu.org (opensmtpd-pki
>> +                        (domain "smtp.gnu.org")
>> +                        (cert "file.cert")
>> +                        (key "file.key"))))
>> +  (service opensmtpd-service-type
>> +           (opensmtpd-configuration
>> +            (interfaces (list
>> +                         (opensmtpd-interface
>> +                          (pki smtp.gnu.org))
>> +                         (opensmtpd-interface
>> +                          (pki smtp.gnu.org)
>> +                          (secure-connection "smtps"))))
>> +            (matches (list
>> +                      (opensmtpd-match
>> +                       (action
>> +                        (opensmtpd-local-delivery
>> +                         (name "local-delivery"))))
>> +                      (opensmtpd-match
>> +                       (action
>> +                        (opensmtpd-relay
>> +                         (name "relay")))))))))
>>  @end lisp
>>  @end deffn
>>  
>> @@ -25425,7 +25475,7 @@ Data type representing the configuration of
>> opensmtpd.
>>  
>>  @table @asis
>>  @item @code{package} (default: @var{opensmtpd})
>> -Package object of the OpenSMTPD SMTP server.
>> +Package object of the OpenSMTPD server.
>>  
>>  @item @code{config-file} (default: @code{%default-opensmtpd-config-
>> file})
>>  File-like object of the OpenSMTPD configuration file to use.  By
>> default
>> @@ -25433,14 +25483,1013 @@ it listens on the loopback network
>> interface, and allows for mail from
>>  users and daemons on the local machine, as well as permitting email
>> to
>>  remote servers.  Run @command{man smtpd.conf} for more information.
>>  
>> +@item @code{bounce} (default: @code{(list "4h")})
>> +@code{bounce} is a list of strings, which send warning messages to
>> the
>> +envelope sender when temporary delivery failures cause a message to
>> +remain in the queue for longer than a specified delay. Each delay
>> option
>> +is a string parameter beginning with a positive decimal integer and
>> a
>> +unit, which can be 's', 'm', 'h', or 'd'. At most four delay
>> parameters
>> +can be specified.
>> +
>> +@item @code{interfaces} default:
>> +@lisp
>> +(list
>> +  (opensmtpd-interface
>> +    (interface "lo")
>> +    (port 25)))
>> +@end lisp
>> +@code{interfaces} is a list of @code{<opensmtpd-interface>} records.
>> +This list details what interfaces and ports OpenSMTPD listens on as
>> well as
>> +other options.
>> +
>> +@item @code{socket} (default: @code{(opensmtpd-socket)})
>> +Listens for incoming connections on the Unix domain socket.
>> +
>> +@item @code{includes} (default: @code{#f})
>> +@code{includes} is a list of string filenames. Each filename's
>> contents is
>> +additional configuration that is inserted into the top of the
>> configuration
>> +file.  Run @code{man smtpd.conf} for more information.
>> +
>> +@item @code{matches} default:
>> +@lisp
>> +(list (opensmtpd-match
>> +       (action (opensmtpd-local-delivery
>> +                (name "local")
>> +                (method "mbox")
>> +                (options
>> +                 (list
>> +                  (opensmtpd-option
>> +                   (option "for local")))))))
>> +      (opensmtpd-match
>> +       (action (opensmtpd-relay
>> +                (name "outbound")))
>> +       (options
>> +        (list
>> +         (opensmtpd-option
>> +          (option "from local"))
>> +         (opensmtpd-option
>> +          (option "for any"))))))
>> +@end lisp
>> +@code{matches} is a list of @code{<opensmtpd-match>} records, which
>> +matches incoming mail and sends it to a correspending action. The
>> match
>> +records are evaluated sequentially, with the first match winning.
>> +Therefore @emph{the order that you arrange your matches is
>> important}.
>> +It's a good idea to put specific matches first and an all
>> emcompassing
>> +match (like @code{(option "for any")}) @strong{last}. If an incoming
>> +mail does not match any match records, then it is rejected.
>> +
>> +@item @code{mta-max-deferred} (default: @code{100})
>> +When delivery to a given host is suspended due to temporary
>> failures, cache
>> +at most number envelopes for that host such that they can be
>> delivered as
>> +soon as another delivery succeeds to that host. The default is 100.
>> +
>> +@item @code{queue} (default: @code{#f})
>> +@code{queue} expects an @code{<opensmtpd-queue>} record. With it,
>> one may
>> +compress and encrypt queue-ed emails as well as set the default
>> expiration
>> +time for temporarily undeliverable messages.
>> +
>> +@item @code{smtp} (default: @code{#f})
>> +@code{smtp} expects an @code{<opensmtpd-smtp>} record, which lets
>> one
>> +specifiy how large email may be along with other settings.
>> +
>> +@item @code{srs} (default: @code{#f})
>> +@code{srs} expects an @code{<opensmtpd-srs>} record, which lets one
>> set
>> +up SRS, the Sender Rewritting Scheme.
>> +
>>  @item @code{setgid-commands?} (default: @code{#t})
>>  Make the following commands setgid to @code{smtpq} so they can be
>>  executed: @command{smtpctl}, @command{sendmail}, @command{send-
>> mail},
>>  @command{makemap}, @command{mailq}, and @command{newaliases}.
>>  @xref{Setuid Programs}, for more information on setgid programs.
>> +
>>  @end table
>>  @end deftp
>>  
>> +@itemize
>> +@item Data Type: opensmtpd-interface
>> +Data type representing the configuration of an
>> +@code{<opensmtpd-interface>}. It listens on the fieldname
>> +@code{interface} for incoming connections, using the same syntax as
>> +@code{ifconfig}. The interface parameter may also be an string
>> interface
>> +group, an string IP address, or a string domain name. Listening can
>> +optionally be restricted to a specific address via the fieldname
>> +@code{family}, which can be either @code{"inet4"} or @code{"inet6"}.
>> +
>> +@itemize
>> +@item @code{interface} (default: @code{"lo"})
>> +
>> +The string interface to listen for incoming connections.  This
>> string
>> +may be an interface group, an IP address, or a domain name. These
>> +interfaces can usually be found by the command @code{ip link}.
>> +
>> +@item @code{family} (default: @code{#f})
>> +
>> +Only listen on a specific address family.  Valid strings are
>> +@code{"inet4"} or @code{"inet6"}, which will only listen on IPv4 or
>> IPv6
>> +respectfully.  If @code{(family #f)}, then opensmtpd will listen on
>> both
>> +IPv4 and IPv6.
>> +
>> +@item @code{auth} (default: @code{#f})
>> +Support SMTPAUTH: clients may only start SMTP transactions after
>> +successful authentication. If @code{auth} is @code{#t}, then users
>> are
>> +authenticated against their own normal login credentials.
>> Alternatively
>> +@code{auth} may be a @code{mapping table} that maps usernames to
>> +encrypted passwords.  The password can be encrypted via the
>> +@code{smtpctl} @code{encrypt} subcommand.
>> +
>> +@item @code{auth-optional} (default: @code{#f})
>> +Support SMTPAUTH optionally: clients need not authenticate, but may
>> do
>> +so.  This allows the @code{<opensmtpd-interface>} to both accept
>> +incoming mail from untrusted senders and permit outgoing mail from
>> +authenticated users. It can be used in situations where it is not
>> +possible to listen on a separate port (usually the submission port,
>> 587)
>> +for users to authenticate.  This option also accepts a @code{mapping
>> +table} that maps usernames to encrypted passwords.
>> +
>> +@item @code{filters} (default: @code{#f})
>> +A list of one or many @code{<opensmtpd-filter>} or
>> +@code{<opensmtpd-filter-phase>} records. The filters are applied
>> +sequentially. These records listen and filter on connections handled
>> by this
>> +listener.
>> +
>> +@item @code{hostname} (default: @code{#f})
>> +Change the default server name in the greeting banner instead of the
>> +default one.
>> +
>> +@item @code{hostnames} (default: @code{#f})
>> +Override the server name for specific addresses. Use a @code{mapping
>> +table} that maps string IP addresses to string hostnames. If the
>> address
>> +on which the connection arrives appears in the mapping, the
>> associated
>> +hostname is used.
>> +
>> +@item @code{mask-src} (default: @code{#f})
>> +If @code{#t}, then omit the from part when prepending “Received”
>> headers.
>> +
>> +@item @code{disable-dsn} (default: @code{#f})
>> +When @code{#t}, then disable the DSN (Delivery Status Notification)
>> extension.
>> +
>> +@item @code{pki} (default: @code{#f})
>> +For secure connections, use an @code{<opensmtpd-pki>} record to
>> prove a
>> +mail server's identity.
>> +
>> +@item @code{port} (default: @code{25})
>> +Listen on the integer port instead of the default port of 25.
>> +
>> +@item @code{proxy-v2} (default: @code{#f})
>> +If @code{#t}, then support the PROXYv2 protocol, rewriting
>> appropriately source
>> +address received from proxy.
>> +
>> +@item @code{received-auth} (default: @code{#f})
>> +If @code{#t}, then in “Received” headers, report whether the session
>> was
>> +authenticated and by which local user.
>> +
>> +@item @code{senders} (default: @code{#f})
>> +Look up the authenticated user in the supplied @code{mapping table}
>> to
>> +find the email addresses that user is allowed to submit mail as.
>> +
>> +@item @code{masquerade} (default: @code{#f})
>> +@code{masquerade}, is used in conjunction with @code{senders}.  If
>> +@code{#t}, then the From header is rewritten to match the sender
>> +provided in the SMTP session.  If @code{senders} is @code{#false},
>> then
>> +@code{masquerade} cannot be @code{#t}.
>> +
>> +@item @code{secure-connection} (default: @code{#f})
>> +This is a string of one of these options:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> Same here

Are you saying secure-connection is not documented?

It's documented in the table just below:

>> +@item @code{"smtps"}
>> +@tab Support SMTPS, by default on port 465.
>> +@item @code{"tls"}
>> +@tab Support STARTTLS, by default on port 25.
>> +@item @code{"tls-require"}
>> +@tab Like @code{"tls"}, but force clients to
>> +@item
>> +@tab establish a secure connection before being
>> +@item
>> +@tab allowed to start an SMTP transaction.
>> +@item @code{"tls-require-verify"}
>> +@tab Like @code{"tls-require"}, but clients must
>> +@item
>> +@tab also provide a valid certificate
>> +@item
>> +@tab to establish an SMTP session.
>> +@end multitable
>> +
>> +@item @code{tag} (default: @code{#f})
>> +Clients connecting to the listener are tagged with the given string
>> tag.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-socket
>> +Data type representing the configuration of an
>> +@code{<opensmtpd-socket>}. Listen for incoming SMTP connections on
>> the
>> +Unix domain socket @samp{/var/run/smtpd.sock}. This is done by
>> default,
>> +even if the record is absent.
>> +
>> +@itemize
>> +@item @code{filters} (default: @code{#f})
>> +A list of one or many @code{<opensmtpd-filter>} or
>> +@code{<opensmtpd-filter-phase>} records. These filter incoming
>> +connections handled by this listener.
>> +
>> +@item @code{mask-src} (default: @code{#f})
>> +If @code{#t}, then omit the from part when prepending “Received”
>> headers.
>> +
>> +@item @code{tag} (default: @code{#f})
>> +Clients connecting to the listener are tagged with the given string
>> tag.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-match
>> +@cindex opensmtpd-match
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-match>} record.
>> +
>> +If at least one mail envelope matches the options of one match
>> record,
>> +receive the incoming message, put a copy into each matching
>> envelope,
>> +and atomically save the envelopes to the mail spool for later
>> processing
>> +by the respective @code{<opensmtpd-action>} found in fieldname
>> +@code{action}.  Here is an example @code{opensmtpd-match}
>> +record.
>> +
>> +@lisp
>> +(opensmtpd-match
>> + (action (opensmtpd-local-delivery
>> +          (name "receive")
>> +          (method (opensmtpd-maildir
>> +                   (pathname "/home/%@{rcpt.user@}/Maildir")
>> +                   (junk #t)))
>> +          (virtual (opensmtpd-table
>> +                    (name "virt")
>> +                    (data '(("carmen" . "carmen@@gnu.org")))))))
>> + (options (list (opensmtpd-option
>> +                 (option "from any"))
>> +                (opensmtpd-option
>> +                 (option "for domain")
>> +                 (data (opensmtpd-table
>> +                        (name "domain-table")
>> +                        (data (list "gnu.org" "fsf.org"))))))))
>> +@end lisp
>> +
>> +@itemize
>> +@item @code{action} (default: @code{#f})
>> +
>> +If mail matches this match configuration, then do this action. Valid
>> values
>> +include @code{<opensmtpd-local-delivery>} or
>> +@code{<opensmtpd-relay>}.
>> +
>> +@item @code{options} (default: @code{#f})
>> +The fieldname @code{option} is a list of unique
>> +@code{<opensmtpd-option>} records.
>> +
>> +There are some mutually exclusive options: there can be only one
>> ``for''
>> +and only one ``from'' option.
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> and here.

If you are referring to <opensmtpd-option> is it documented like this:

• Data Type: opensmtpd-option This data type represents the
  configuration of an ‘<opensmtpd-option>’, which is used by
  ‘<opensmtpd-filter-phase>’ and ‘<opensmtpd-match>’ to match various
  options for email.

(sorry about the above formatting). That is currently how the documentation is
generated. I need to go through the documentation is fix that. I did
<opensmtpd-configuration> correctly.


>> +@headitem for
>> +@tab from
>> +@item only use one of the following:
>> +@tab only use one of the following:
>> +@item @code{"for any"}
>> +@tab @code{"from any"}
>> +@item @code{"for local"}
>> +@tab @code{"from auth"}
>> +@item @code{"for domain"}
>> +@tab @code{"from local"}
>> +@item @code{"for rcpt-to"}
>> +@tab @code{"from mail-from"}
>> +@item
>> +@tab @code{"from socket"}
>> +@item
>> +@tab @code{"from src"}
>> +@end multitable
>> +
>> +Additionally, some options require additional data via
>> +@code{<opensmtpd-option>}'s fieldname @code{data}.  The following
>> list
>> +will explain the below syntax.
>> +
>> +@itemize
>> +@item @code{"for any"}
>> +This option only requires fieldname @code{option} to have the string
>> +@code{"for any"}:
>> +
>> +@lisp
>> +      (opensmtpd-option
>> +       (option "for any"))
>> +@end lisp
>> +
>> +@item @code{"tag"} _tag_
>> +This option only requires fieldname @code{option} to have the string
>> +@code{"tag"} with a string in fieldname @code{data}:
>> +
>> +@lisp
>> +      (opensmtpd-option
>> +       (option "tag")
>> +       (data "this-tag"))
>> +@end lisp
>> +
>> +@item @code{"for rcpt"} _domain_ | <list table>
>> +This option requires fieldname @code{data} to have a string domain
>> or
>> +@code{list table}:
>> +
>> +@lisp
>> +      (opensmtpd-option
>> +       (option "for rcpt")
>> +       (data "gnu.org"))
>> +@end lisp
>> +
>> +OR
>> +
>> +@lisp
>> +      (opensmtpd-option
>> +       (option "for rcpt")
>> +       (data (list "gnu.org" "fsf.org")))
>> +@end lisp
>> +@end itemize
>> +
>> +The following matching options are supported and can all be negated
>> (via not
>> +#t). The options that support a table (anything surrounded with '<'
>> and '>'
>> +eg: <table>), also support specifying regex via (regex #t).
>> +
>> +@itemize
>> +@item @code{"for any"}
>> +Specify that session may address any destination.
>> +
>> +@item @code{"for local"}
>> +Specify that session may address any local domain.  This is the
>> default,
>> +and may be omitted.
>> +
>> +@item @code{"for domain"} _domain_ | <domain>
>> +Specify that session may address the string _domain_ or
>> +@code{list table} <domain>.
>> +
>> +@item @code{"for rcpt-to"} _recipient_ | <recipient>
>> +Specify that session may address the string _recipient_ or list
>> table
>> +<recipient>.
>> +
>> +@item @code{"from any"}
>> +Specify that session may originate from any source.
>> +
>> +@item @code{"from auth"}
>> +Specify that session may originate from any authenticated user, no
>> matter
>> +the source IP address.
>> +
>> +@item @code{"from auth"} _user_ | <user>
>> +Specify that the session may originate from authenticated _user_ or
>> +@code{list table} <user>, no matter the source IP address.
>> +
>> +@item @code{"from local"}
>> +Specify that session may only originate from a local IP address, or
>> from
>> +the local enqueuer.  This is the default, and may be omitted.
>> +
>> +@item @code{"from mail-from"} _sender_ | <sender>
>> +Specify that session may originate from _sender_ or @code{list
>> table}
>> +<sender>, no matter the source IP address.
>> +
>> +@item @code{"from rdns"}
>> +Specify that session may only originate from an IP address that
>> resolves
>> +to a reverse DNS@.
>> +
>> +@item @samp{"from rdns"} _hostname_ | <hostname>
>> +Specify that session may only originate from an IP address that
>> resolves
>> +to a reverse DNS matching string _hostname_ or @code{list table}
>> +<hostname>.
>> +
>> +@item @samp{"from socket"}
>> +Specify that session may only originate from the local enqueuer.
>> +
>> +@item @code{"from src"} _address_ | <address>
>> +Specify that session may only originate from string _address_ or
>> +@code{list table} <address> which can be a specific address or a
>> subnet
>> +expressed in CIDR-notation.
>> +
>> +@item @code{"auth"}
>> +Matches transactions which have been authenticated.
>> +
>> +@item @code{"auth"} _username_ | <username>
>> +Matches transactions which have been authenticated for string _user_
>> or
>> +@code{list table} <username>.
>> +
>> +@item @code{"helo"} _helo-name_ | <helo-name>
>> +Specify that session's HELO / EHLO should match the string _helo-
>> name_
>> +or @code{list table} <helo-name>.
>> +
>> +@item @code{"mail-from"} _sender_ | <sender>
>> +Specify that transactions's MAIL FROM should match the string
>> _sender_
>> +or @code{list table} <sender>.
>> +
>> +@item @code{"rcpt-to"} _recipient_ | <recipient>
>> +Specify that transaction's RCPT TO should match the string
>> _recipient_
>> +or @code{list table} <recipient>.
>> +
>> +@item @code{"tag"} _tag_
>> +Matches transactions tagged with the given tag.
>> +
>> +@item @code{"tls"}
>> +Specify that transaction should take place in a TLS channel.
>> +@end itemize
>> +
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-local-delivery
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-local-delivery>} record.
>> +
>> +@itemize
>> +@item @code{name} (default: @code{#f})
>> +@code{name} is the string name of the relay action.
>> +
>> +@item @code{method} (default: @code{"mbox"})
>> +The email delivery option.  Valid options are:
>> +
>> +@itemize
>> +@item @code{"mbox"}
>> +Deliver the message to the user's mbox with mail.local(8).
>> +
>> +@item @code{"expand-only"}
>> +Only accept the message if a delivery method was specified in an
>> aliases
>> +or .forward file.
>> +
>> +@item @code{"forward-only"}
>> +Only accept the message if the recipient results in a remote address
>> after
>> +the processing of aliases or forward file.
>> +
>> +@item @code{<opensmtpd-lmtp>}
>> +Deliver the message to an LMTP server at @code{<opensmtpd-lmtp>}'s
>> +fieldname @code{destination}. The location may be expressed as
>> string
>> +host:port or as a UNIX socket. Optionally, @code{<opensmtpd-lmtp>}'s
>> +fieldname @code{rcpt-to} might be specified to use the recipient
>> email
>> +address (after expansion) instead of the local user in the LMTP
>> session
>> +as RCPT TO.
>> +
>> +@item @code{<opensmtpd-maildir>}
>> +Deliver the message to the maildir in
>> +@code{<opensmtpd-maildir>}'s fieldname @code{pathname} if specified,
>> +or by default to @code{"~/Maildir"}.
>> +
>> +The pathname may contain format specifiers that are expanded before
>> use
>> +(see the below section about Format Specifiers).
>> +
>> +If @code{<opensmtpd-maildir>}'s record fieldname @code{junk} is
>> @code{#t},
>> +then message will be moved to the ‘Junk’ folder if it contains a
>> positive
>> +‘X-Spam’ header. This folder will be created under fieldname
>> @code{pathname} if
>> +it does not yet exist.
>> +
>> +@item @code{<opensmtpd-mda>}
>> +Delegate the delivery to the @code{<opensmtpd-mda>}'s fieldname
>> +@code{command} (type string) that receives the message on its
>> standard input.
>> +
>> +The @code{command} may contain format specifiers that are expanded
>> before use
>> +(see Format Specifiers).
>> +@end itemize
>> +
>> +@item @code{alias} (default: @code{#f})
>> +Use the @code{mapping table} for aliases expansion.
>> +
>> +@item @code{ttl} (default: @code{#f})
>> +@code{ttl} is a string specify how long a message may remain in the
>> queue.  It's
>> +format is @code{n@{s|m|h|d@}}.  eg: @code{"4m"} is four minutes.
>> +
>> +@item @code{user} (default: @code{#f} )
>> +@code{user} is the string username for performing the delivery, to
>> be looked up
>> +with getpwnam(3).
>> +
>> +This is used for virtual hosting where a single username is in
>> charge of
>> +handling delivery for all virtual users.
>> +
>> +This option is not usable with the mbox delivery method.
>> +
>> +@item @code{userbase} (default: @code{#f})
>> +@code{userbase} is an @code{<opensmtpd-table>} record for mapping
>> user
>> +lookups instead of the getpwnam(3) function.
>> +
>> +The fieldnames @code{user} and @code{userbase} are mutually
>> exclusive.
>> +
>> +@item @code{virtual} (default: @code{#f})
>> +@code{virtual} is an @code{<opensmtpd-table>} record is used for
>> virtual
>> +expansion.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-relay
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-relay>} record.
>> +
>> +@itemize
>> +@item @code{name} (default: @code{#f})
>> +@code{name} is the string name of the relay action.
>> +
>> +@item @code{backup} (default: @code{#f})
>> +When @code{#t}, operate as a backup mail exchanger delivering
>> messages to any
>> +mail exchanger with higher priority.
>> +
>> +@item @code{backup-mx} (default: @code{#f})
>> +Operate as a backup mail exchanger delivering messages to any mail
>> exchanger
>> +with higher priority than mail exchanger identified as string name.
>> +
>> +@item @code{helo} (default: @code{#f})
>> +Advertise string heloname as the hostname to other mail exchangers
>> during
>> +the HELO phase.
>> +
>> +@item @code{helo-src} (default: @code{#f} )
>> + Use the mapping @code{<opensmtpd-table>} to look up a hostname
>> +matching the source address, to advertise during the HELO phase.
>> +
>> +@item @code{domain} (default: @code{#f})
>> +Do not perform MX lookups but look up destination domain in an
>> +@code{<opensmtpd-table>} and use matching relay url as relay host.
>> +
>> +@item @code{host} (default: @code{#f})
>> +Do not perform MX lookups but relay messages to the relay host
>> described by
>> +the string relay-url. The format for relay-url is
>> +@samp{[proto://[label@@]]host[:port]}. The following protocols are
>> available:
>> +
>> +@multitable {aaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
> AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA.

Are you giving me a triple A+ ? :) Org generated the the like that. I think you
mentioned that I should use fractions last time. Sorry I did not do that. If I
wait 'til I implement every one of your suggestions, I will probably never
submit it. I am really probably "perfecting" this service.

>> +@item @code{smtp}
>> +@tab Normal SMTP session with opportunistic STARTTLS (the default).
>> +@item @code{smtp+tls}
>> +@tab Normal SMTP session with mandatory STARTTLS@.
>> +@item @code{smtp+notls}
>> +@tab Plain text SMTP session without TLS@.
>> +@item @code{lmtp}
>> +@tab LMTP session.  port is required.
>> +@item @code{smtps}
>> +@tab SMTP session with forced TLS on connection, default port is
>> +@item
>> +@tab 465.
>> +@end multitable
>> +
>> +Unless noted, port defaults to 25.
>> +
>> +The label corresponds to an entry in a credentials table, as
>> documented in
>> +@code{man table}. It is used with the @code{"smtp+tls"} and
>> @code{"smtps"} protocols for
>> +authentication. Server certificates for those protocols are verified
>> by
>> +default.
>> +
>> +@item @code{pki} (default: @code{#f})
>> +For secure connections, use the certificate associated with
>> +@code{<opensmtpd-pki>} (declared in a pki directive) to prove the
>> +client's identity to the remote mail server.
>> +
>> +@item @code{srs} (default: @code{#f})
>> +If @code{#t}, then when relaying a mail resulting from a forward,
>> use the Sender
>> +Rewriting Scheme to rewrite sender address.
>> +
>> +@item @code{tls} (default: @code{#f}) boolean or string ``no-
>> verify''
> Instead of a string, take 'no-verify as symbol perhaps?

Sounds good to me. May I ask why you prefer a symbol instead of a string?

>> +When @code{#t}, Require TLS to be used when relaying, using
>> mandatory STARTTLS by
>> +default. When used with a smarthost, the protocol must not be
>> +@samp{"smtp+notls://"}. When string @code{"no-verify"}, then do not
>> require a valid
>> +certificate.
>> +
>> +@item @code{auth} (default: @code{#f}) @code{<opensmtpd-table>}
>> +Use the alist @code{<opensmtpd-table>} for connecting to relay-url
>> +using credentials. This option is usable only with fieldname
>> @code{host} option.
>> +
>> +@item @code{mail-from} (default: @code{#f}) string
>> +Use the string mailaddress as MAIL FROM address within the SMTP
>> transaction.
>> +
>> +@item @code{src} (default: @code{#f}) string | @code{<opensmtpd-
>> table>}
>> +Use the string or @code{<opensmtpd-table>} sourceaddr for the
>> +source IP address, which is useful on machines with multiple
>> interfaces. If
>> +the list contains more than one address, all of them are used in
>> such a way
>> +that traffic is routed as efficiently as possible.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-filter
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-filter>}. This is the filter record one should use
>> +if they want to use an external package to filter email eg: rspamd
>> or
>> +spamassassin.
>> +
>> +@itemize
>> +@item @code{name} (default: @code{#f})
>> +The string name of the filter.
>> +
>> +@item @code{proc} (default: @code{#f})
>> +The string command or process name.  If @code{proc-exec} is
>> @code{#t}, @code{proc} is
>> +treated as a command to execute.  Otherwise, it is a process name.
>> +
>> +@item @code{proc-exec} (default: @code{#f})
>> +If @code{#t}, then execute the command in @code{proc}.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-filter-phase
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-filter-phase>}.
>> +
>> +In a regular workflow, @code{smtpd(8)} may accept or reject a
>> message
>> +based only on the content of envelopes. Its decisions are about the
>> +handling of the message, not about the handling of an active
>> session.
>> +
>> +Filtering extends the decision making process by allowing
>> +@code{smtpd(8)} to stop at each phase of an SMTP session, check that
>> +options are met, then decide if a session is allowed to move
>> forward.
>> +
>> +With filtering via an @code{<opensmtpd-filter-phase>} record, a
>> +session may be interrupted at any phase before an envelope is
>> complete. A
>> +message may also be rejected after being submitted, regardless of
>> whether the
>> +envelope was accepted or not.
>> +
>> +@itemize
>> +@item @code{name} (default: @code{#f})
>> +
>> +The string name of the filter phase.
>> +
>> +@item @code{phase-name} (default: @code{#f})
>> +The string name of the phase. Valid values are:
>> +
>> +@multitable {aaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
>> +@item @code{"connect"}
>> +@tab upon connection, before a banner is displayed
>> +@item @code{"helo"}
>> +@tab after HELO command is submitted
>> +@item @code{"ehlo"}
>> +@tab after EHLO command is submitted
>> +@item @code{"mail-from"}
>> +@tab after MAIL FROM command is submitted
>> +@item @code{"rcpt-to"}
>> +@tab after RCPT TO command is submitted
>> +@item @code{"data"}
>> +@tab after DATA command is submitted
>> +@item @code{"commit"}
>> +@tab after message is fully is submitted
>> +@end multitable
>> +
>> +@item @code{options} (default @code{#f})
>> +A list of unique @code{<opensmtpd-option>} records.
>> +
>> +At each phase, various options, specified by a list of
>> +@code{<opensmtpd-option>}, may be checked. The
>> +@code{<opensmtpd-option>}'s fieldname @code{option} values of:
>> +@code{"fcrdns"}, @code{"rdns"}, and @code{"src"} data are available
>> in
>> +all phases, but other data must have been already submitted before
>> they
>> +are available. Options with a @code{<table>} next to them require
>> the
>> +@code{<opensmtpd-option>}'s fieldname @code{data} to be an
>> +@code{<opensmtpd-table>}. There are the available options:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
>> +@item @code{"fcrdns"}
>> +@tab forward-confirmed reverse DNS is valid
>> +@item @code{"rdns"}
>> +@tab session has a reverse DNS
>> +@item @code{"rdns"} <table>
>> +@tab session has a reverse DNS in table
>> +@item @code{"src"} <table>
>> +@tab source address is in table
>> +@item @code{"helo"} <table>
>> +@tab helo name is in table
>> +@item @code{"auth"}
>> +@tab session is authenticated
>> +@item @code{"auth"} <table>
>> +@tab session username is in table
>> +@item @code{"mail-from"} <table>
>> +@tab sender address is in table
>> +@item @code{"rcpt-to"} <table>
>> +@tab recipient address is in table
>> +@end multitable
>> +
>> +These conditions may all be negated by setting
>> +@code{(opensmtpd-option (bool #f))}.
>> +
>> +Any conditions that require a table may indicate that tables include
>> regexs
>> +setting @code{(opensmtpd-option (regex #t))}.
>> +
>> +@item @code{decision}
>> +A string decision to be taken. Some decisions require an
>> @code{message}
>> +or @code{value}.  The value and message may be put in the
>> +@code{<opensmtpd-option>}'s fieldname @code{data}.  Valid strings
>> are:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
>> +@item @code{"bypass"}
>> +@tab the session or transaction bypasses filters
>> +@item @code{"disconnect"} message
>> +@tab the session is disconnected with message
>> +@item @code{"junk"}
>> +@tab the session or transaction is junked,
>> +@item
>> +@tab  i.e., an ‘X-Spam: yes’ header is added to
>> +@item
>> +@tab any messages
>> +@item @code{"reject"} message
>> +@tab the command is rejected with message
>> +@item @code{"rewrite"} value
>> +@tab the command parameter is rewritten with value
>> +@end multitable
>> +
>> +Decisions that involve a message require that the message be RFC
>> valid,
>> +meaning that they should either start with a 4xx or 5xx status code.
>> +Descisions can be taken at any phase, though junking can only happen
>> before
>> +a message is committed.
>> +
>> +@item @code{message} (default @code{#f})
>> +A string message beginning with a 4xx or 5xx status code.
>> +
>> +@item @code{value} (default: @code{#f})
>> +A number value.  @code{value} and @code{message} are mutually
>> exclusive.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-option
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-option>}, which is used by
>> +@code{<opensmtpd-filter-phase>} and @code{<opensmtpd-match>}
>> +to match various options for email.
>> +
>> +@itemize
>> +@item @code{option} (default @code{#f}) string
>> +
>> +A string option to be taken. Some options require the fieldname
>> +@code{data} to have a string or an @code{<opensmtpd-table>}. When
>> the
>> +option record is used inside of an @code{<opensmtpd-filter-phase>},
>> then
>> +valid strings for fieldname @code{option} are:
>> +
>> +@itemize
>> +@item @code {"fcrdns"}
>> +@item @code {"rdns"}
>> +@item @code {"src"}
>> +@item @code {"helo"}
>> +@item @code {"auth"}
>> +@item @code {"mail-from"}
>> +@item @code {"rcpt-to"}
>> +@end itemize
>> +
>> +When @code{<opensmtpd-option>} is used inside of an
>> +@code{<opensmtpd-match>}, then valid strings for fieldname
>> @code{option}
>> +are:
>> +
>> +@itemize
>> +@item @code {"for"}
>> +@item @code {"for any"}
>> +@item @code {"for local"}
>> +@item @code {"for domain"}
>> +@item @code {"for rcpt-to"}
>> +@item @code {"from any"}
>> +@item @code {"from auth"}
>> +@item @code {"from local"}
>> +@item @code {"from mail-from"}
>> +@item @code {"from rdns"}
>> +@item @code {"from socket"}
>> +@item @code {"from src"}
>> +@item @code {"auth"}
>> +@item @code {"helo"}
>> +@item @code {"mail-from"}
>> +@item @code {"rcpt-to"}
>> +@item @code {"tag"}
>> +@item @code {"tls"}
>> +@end itemize
>> +
>> +@item @code{data} (default @code{#f}) string | @code{<opensmtpd-
>> table>}
>> +Some options require a string or @code{<opensmtpd-table>} to be
>> +present. One would specify that table here.
>> +
>> +@item @code{regex} (default: @code{#f}) boolean
>> +Any options using a table may indicate that tables hold regular
>> +expressions by setting this option to @code{#t}.
>> +
>> +@item @code{bool} (default: @code{#t}) boolean
>> +When @code{(bool #f)}, this option record is negated.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-table
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-table>}.
>> +
>> +@itemize
>> +@item @code{name} (default @code{#f})
>> +@code{name} is the name of the @code{<opensmtpd-table>} record.
>> +
>> +@item @code{data} (default: @code{#f}) string | list | alist |
>> nested-list
>> +@code{data} expects a string, a list of strings, an alist of
>> strings, or
>> +a nested list of strings.
>> +eg:
>> +
>> +@itemize
>> +
>> +@item string
>> +@lisp
>> +(data "dev@@gnu.org")
>> +@end lisp
>> +
>> +A table of this type is called a @code{string table}.
>> +
>> +@item list
>> +@lisp
>> +(data (list ("gnu.org" "fsf.org")))
>> +@end lisp
>> +
>> +A table of this type is called a @code{list table}.
>> +
>> +@item alist
>> +@lisp
>> +(data '(("james" . "$encryptedPassword")
>> +        ("jennifer" . "$encryptedPassword2)))
>> +@end lisp
>> +
>> +A table of this type is called a @code{mapping table}.
>> +
>> +@item nested-list
>> +@lisp
>> +(data '(("user1" "root@@gnu.org" "admin@@gnu.org")
>> +        ("user2" "james@@guix.gnu.org" "sarah@@fsf.org")))
>> +@end lisp
>> +
>> +A table of this type is also called a @code{mapping table}.
>> +
>> +@end itemize
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-pki
>> +This data type represents the configuration of an
>> +@code{<opensmtpd-pki>}.
>> +
>> +@itemize
>> +@item @code{domain} (default @code{#f})
>> +@code{domain} is the string name of the @code{<opensmtpd-pki>}
>> record.
>> +
>> +@item @code{cert} (default: @code{#f})
>> +@code{cert} (default: @code{#f})
>> +
>> +@code{cert} is the string certificate filename to use for this pki.
>> +
>> +@item @code{key} (default: @code{#f})
>> +@code{key} is the string certificate falename to use for this pki.
>> +
>> +@item @code{dhe} (default: @code{"none"})
>> +Specify the DHE string parameter to use for DHE cipher suites with
>> host
>> +pkiname. Valid parameter values are @code{"none"}, @code{"legacy"},
>> or
>> +@code{"auto"}. For @code{"legacy"}, a fixed key length of 1024 bits
>> is
>> +used, whereas for @code{"auto"}, the key length is determined
>> +automatically. The default is @code{"none"}, which disables DHE
>> cipher
>> +suites.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-maildir
>> +@itemize
>> +@item @code{pathname} (default: @code{"~/Maildir"})
>> +Deliver the message to the maildir if pathname if specified, or by
>> default
>> +to @code{"~/Maildir"}.
>> +
>> +The pathname may contain format specifiers that are expanded before
>> use
>> +(see FORMAT SPECIFIERS).
>> +
>> +@item @code{junk} (default: @code{#f})
>> +If the junk argument is @code{#t}, then the message will be moved to
>> the @samp{‘Junk’}
>> +folder if it contains a positive @samp{‘X-Spam’} header. This folder
>> will be
>> +created under pathname if it does not yet exist.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-mda
>> +This record lets you delegate the delivery to a command that
>> receives
>> +the message on its standard input.
>> +
>> +@itemize
>> +@item @code{name}
>> +The string name for this MDA command.
>> +
>> +@item @code{command}
>> +The command to that delivers the mail.
>> +
>> +The command may contain format specifiers that are expanded before
>> use (see
>> +FORMAT SPECIFIERS).
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-queue
>> +@itemize
>> +@item @code{compression} (default @code{#f})
>> +Store queue files in a compressed format. This may be useful to save
>> disk
>> +space.
>> +
>> +@item @code{encryption} (default @code{#f})
>> +Encrypt queue files with EVP@math{_aes}@math{_256}@math{_gcm}(3). If
>> no key is specified, it is
>> +read with getpass(3). If the string stdin or a single dash (‘-’) is
>> given
>> +instead of a key, the key is read from the standard input.
>> +
>> +@item @code{ttl-delay} (default @code{#f})
>> +Set the default expiration time for temporarily undeliverable
>> messages,
>> +given as a positive decimal integer followed by a unit s, m, h, or
>> d. The
>> +default is four days (@code{"4d"}).
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-smtp
>> +Data type representing an @code{<opensmtpd-smtp>} record.
>> +
>> +@itemize
>> +@item @code{ciphers} (default: @code{#f})
>> +Set the control string for
>> SSL@math{_CTX}@math{_set}@math{_cipher}@math{_list}(3).  The default
>> is
>> +         ``HIGH:!aNULL:!MD5''.
>> +
>> +@item @code{limit-max-mails} (default: @code{100})
>> +Limit the number of messages to count for each sessio
>> +
>> +@item @code{limit-max-rcpt} (default: @code{1000})
>> +Limit the number of recipients to count for each transaction.
>> +
>> +@item @code{max-message-size} (default: @code{35M})
>> +Reject messages larger than size, given as a positive number of
>> bytes or as
>> +a string to be parsed with scan@math{_scaled}(3).
>> +
>> +@item @code{sub-addr-delim character} (default: @code{+})
>> +When resolving the local part of a local email address, ignore the
>> ASCII
>> +character and all characters following it. This is helpful for email
>> +filters. @samp{"admin+bills@@gnu.org"} is the same email address as
>> +@samp{"admin@@gnu.org"}. BUT an email filter can filter emails
>> addressed to first
>> +email address into a 'Bills' email folder.
>> +@end itemize
>> +
>> +@item Data Type: opensmtpd-srs
>> +Use this record to set up the Sender Rewriting Scheme (SRS).
>> +
>> +@itemize
>> +@item @code{key} (default: @code{#f})
>> +Set the secret key to use for SRS, the Sender Rewriting Scheme.
>> +
>> +@item @code{backup-key} (default: @code{#f})
>> +Set a backup secret key to use as a fallback for SRS@. This can be
>> used to
>> +implement SRS key rotation.
>> +
>> +@item @code{ttl-delay} (default: @code{"4d"})
>> +Set the time-to-live delay for SRS envelopes. After this delay, a
>> bounce
>> +reply to the SRS address will be discarded to limit risks of forged
>> +addresses.
>> +@end itemize
>> +
>> +@item Format Specifiers
>> +Some configuration records support expansion of their parameters at
>> +runtime. Such records (for example
>> +@code{<opensmtpd-maildir>}, @code{<opensmtpd-mda>}) may use
>> +format specifiers which are expanded before delivery or relaying.
>> The
>> +following formats are currently supported:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
>> +@item @samp{%@{sender@}}
>> +@tab sender email address, may be empty string
>> +@item @samp{%@{sender.user@}}
>> +@tab user part of the sender email address, may be empty
>> +@item @samp{%@{sender.domain@}}
>> +@tab domain part of the sender email address, may be empty
>> +@item @samp{%@{rcpt@}}
>> +@tab recipient email address
>> +@item @samp{%@{rcpt.user@}}
>> +@tab user part of the recipient email address
>> +@item @samp{%@{rcpt.domain@}}
>> +@tab domain part of the recipient email address
>> +@item @samp{%@{dest@}}
>> +@tab recipient email address after expansion
>> +@item @samp{%@{dest.user@}}
>> +@tab user part after expansion
>> +@item @samp{%@{dest.domain@}}
>> +@tab domain part after expansion
>> +@item @samp{%@{user.username@}}
>> +@tab local user
>> +@item @samp{%@{user.directory@}}
>> +@tab home directory of the local user
>> +@item @samp{%@{mbox.from@}}
>> +@tab name used in mbox From separator lines
>> +@item @samp{%@{mda@}}
>> +@tab mda command, only available for mda wrappers
>> +@end multitable
>> +
>> +Expansion formats also support partial expansion using the optional
>> bracket notations
>> +with substring offset.  For example, with recipient domain
>> @samp{“example.org”}:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaa}
>> +@item @samp{%@{rcpt.domain[0]@}}
>> +@tab expands to “e”
>> +@item @samp{%@{rcpt.domain[1]@}}
>> +@tab expands to “x”
>> +@item @samp{%@{rcpt.domain[8:]@}}
>> +@tab expands to “org”
>> +@item @samp{%@{rcpt.domain[-3:]@}}
>> +@tab expands to “org”
>> +@item @samp{%@{rcpt.domain[0:6]@}}
>> +@tab expands to “example”
>> +@item @samp{%@{rcpt.domain[0:-4]@}}
>> +@tab expands to “example”
>> +@end multitable
>> +
>> +In addition, modifiers may be applied to the token.  For example,
>> with recipient
>> +@samp{“User+Tag@@Example.org”}:
>> +
>> +@multitable {aaaaaaaaaaaaaaaaaaaaaaaa}
>> {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
>> +@item @samp{%@{rcpt:lowercase@}}
>> +@tab expands to “user+tag@@example.org”
>> +@item @samp{%@{rcpt:uppercase@}}
>> +@tab expands to “USER+TAG@@EXAMPLE.ORG”
>> +@item @samp{%@{rcpt:strip@}}
>> +@tab expands to “User@@Example.org”
>> +@item @samp{%@{rcpt:lowercasestrip@}}
>> +@tab expands to “user@@example.org”
>> +@end multitable
>> +
>> +For security concerns, expanded values are sanitized and potentially
>> dangerous
>> +characters are replaced with ‘:’. In situations where they are
>> desirable, the
>> +“raw” modifier may be applied. For example, with recipient
>> +@samp{“user+t?g@@example.org”}:
>> +
>> +@multitable {aaaaaaaaaaaaa} {aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa}
>> +@item @samp{%@{rcpt@}}
>> +@tab expands to “user+t:g@@example.org”
>> +@item @samp{%@{rcpt:raw@}}
>> +@tab expands to “user+t?g@@example.org”
>> +@end multitable
>> +@end itemize
>> +
>>  @subsubheading Exim Service
>>  
>>  @cindex mail transfer agent (MTA)
>> diff --git a/gnu/services/mail.scm b/gnu/services/mail.scm
>> index 43f144a42d..4175cab375 100644
>> --- a/gnu/services/mail.scm
>> +++ b/gnu/services/mail.scm
>> @@ -35,6 +35,10 @@ (define-module (gnu services mail)
>>    #:use-module (gnu packages admin)
>>    #:use-module (gnu packages dav)
>>    #:use-module (gnu packages tls)
>> +  #:use-module (guix i18n)
>> +  #:use-module (guix diagnostics)
>> +  #:use-module (guix ui)
>> +  #:use-module (guix utils)
>>    #:use-module (guix records)
>>    #:use-module (guix packages)
>>    #:use-module (guix gexp)
>> @@ -58,10 +62,149 @@ (define-module (gnu services mail)
>>              mailbox-configuration
>>              namespace-configuration
>>  
>> +            opensmtpd-table
>> +            opensmtpd-table?
>> +            opensmtpd-table-name
>> +            opensmtpd-table-data
>> +
>> +            opensmtpd-ca
>> +            opensmtpd-ca?
>> +            opensmtpd-ca-name
>> +            opensmtpd-ca-file
>> +
>> +            opensmtpd-pki
>> +            opensmtpd-pki?
>> +            opensmtpd-pki-domain
>> +            opensmtpd-pki-cert
>> +            opensmtpd-pki-key
>> +            opensmtpd-pki-dhe
>> +
>> +            opensmtpd-local-delivery
>> +            opensmtpd-local-delivery?
>> +            opensmtpd-local-delivery-method
>> +            opensmtpd-local-delivery-alias
>> +            opensmtpd-local-delivery-ttl
>> +            opensmtpd-local-delivery-user
>> +            opensmtpd-local-delivery-userbase
>> +            opensmtpd-local-delivery-virtual
>> +            opensmtpd-local-delivery-wrapper
>> +
>> +            opensmtpd-maildir
>> +            opensmtpd-maildir?
>> +            opensmtpd-maildir-pathname
>> +            opensmtpd-maildir-junk
>> +
>> +            opensmtpd-mda
>> +            opensmtpd-mda-name
>> +            opensmtpd-mda-command
>> +
>> +            opensmtpd-lmtp
>> +            opensmtpd-lmtp-destination
>> +            opensmtpd-lmtp-rcpt
>> +
>> +            opensmtpd-relay
>> +            opensmtpd-relay?
>> +            opensmtpd-relay-name
>> +            opensmtpd-relay-backup
>> +            opensmtpd-relay-backup-mx
>> +            opensmtpd-relay-helo
>> +            opensmtpd-relay-domain
>> +            opensmtpd-relay-host
>> +            opensmtpd-relay-pki
>> +            opensmtpd-relay-srs
>> +            opensmtpd-relay-tls
>> +            opensmtpd-relay-auth
>> +            opensmtpd-relay-mail-from
>> +            opensmtpd-relay-src
>> +
>> +            opensmtpd-option
>> +            opensmtpd-option?
>> +            opensmtpd-option-option
>> +            opensmtpd-option-bool
>> +            opensmtpd-option-regex
>> +            opensmtpd-option-data
>> +
>> +            opensmtpd-filter-phase
>> +            opensmtpd-filter-phase?
>> +            opensmtpd-filter-phase-name
>> +            opensmtpd-filter-phase-phase
>> +            opensmtpd-filter-phase-options
>> +            opensmtpd-filter-phase-decision
>> +            opensmtpd-filter-phase-message
>> +            opensmtpd-filter-phase-value
>> +
>> +            opensmtpd-filter
>> +            opensmtpd-filter?
>> +            opensmtpd-filter-name
>> +            opensmtpd-filter-proc
>> +
>> +            opensmtpd-interface
>> +            opensmtpd-interface?
>> +            opensmtpd-interface-interface
>> +            opensmtpd-interface-family
>> +            opensmtpd-interface-auth
>> +            opensmtpd-interface-auth-optional
>> +            opensmtpd-interface-filters
>> +            opensmtpd-interface-hostname
>> +            opensmtpd-interface-hostnames
>> +            opensmtpd-interface-mask-src
>> +            opensmtpd-interface-disable-dsn
>> +            opensmtpd-interface-pki
>> +            opensmtpd-interface-port
>> +            opensmtpd-interface-proxy-v2
>> +            opensmtpd-interface-received-auth
>> +            opensmtpd-interface-senders
>> +            opensmtpd-interface-masquerade
>> +            opensmtpd-interface-secure-connection
>> +            opensmtpd-interface-tag
>> +
>> +            opensmtpd-socket
>> +            opensmtpd-socket?
>> +            opensmtpd-socket-filters
>> +            opensmtpd-socket-mask-src
>> +            opensmtpd-socket-tag
>> +
>> +            opensmtpd-match
>> +            opensmtpd-match?
>> +            opensmtpd-match-action
>> +            opensmtpd-match-options
>> +
>> +            opensmtpd-smtp
>> +            opensmtpd-smtp?
>> +            opensmtpd-smtp-ciphers
>> +            opensmtpd-smtp-limit-max-mails
>> +            opensmtpd-smtp-limit-max-rcpt
>> +            opensmtpd-smtp-max-message-size
>> +            opensmtpd-smtp-sub-addr-delim character
>> +
>> +            opensmtpd-srs
>> +            opensmtpd-srs?
>> +            opensmtpd-srs-key
>> +            opensmtpd-srs-backup-key
>> +            opensmtpd-srs-ttl-delay
>> +
>> +            opensmtpd-queue
>> +            opensmtpd-queue?
>> +            opensmtpd-queue-compression
>> +            opensmtpd-queue-encryption
>> +            opensmtpd-queue-ttl-delay
>> +
>>              opensmtpd-configuration
>>              opensmtpd-configuration?
>> +            opensmtpd-package
>> +            opensmtpd-config-file
>> +            opensmtpd-configuration-bounce
>> +            opensmtpd-configuration-cas
>> +            opensmtpd-configuration-interfaces
>> +            opensmtpd-configuration-socket
>> +            opensmtpd-configuration-includes
>> +            opensmtpd-configuration-matches
>> +            ;;opensmtpd-configuration-mda-wrappers
>> +            opensmtpd-configuration-mta-max-deferred
>> +            opensmtpd-configuration-srs
>> +            opensmtpd-configuration-smtp
>> +            opensmtpd-configuration-queue
>>              opensmtpd-service-type
>> -            %default-opensmtpd-config-file
>>  
>>              mail-aliases-service-type
>>  
>> @@ -1641,22 +1784,2351 @@ (define (generate-dovecot-documentation)
>>         (listeners unix-listener-configuration fifo-listener-
>> configuration
>>                    inet-listener-configuration))
>>        (protocol-configuration ,protocol-configuration-fields))
>> -  'dovecot-configuration))
>> +   'dovecot-configuration))
>>  
>>  \f
>> -;;;
>>  ;;; OpenSMTPD.
>>  ;;;
>> +;;; This next bit of code helps me create my own sanitizer
>> functions.
>> +
>> +;; some fieldnames have a default value of #f, which is ok.  They
>> cannot have
>> +;; a value of #t.
>> +;; for example opensmtpd-table-data can be #f, BUT NOT true.
>> +;; my/sanitize procedure tests values to see if they are of the
>> right kind.
>> +;; procedure false? is needed to allow fields like 'values' to be
>> blank,
>> +;; (empty), or #f BUT also have a value like a list of strings.
> Use less egocentric comments ;)

I'm not sure what you mean here? I know I had a comment in my task list that
said something like my sanitizer function are probably better than those found
in guix. Apologies for that.

>
>> +(define (false? var)
>> +  (eq? #f var))
>> +
>> +;; TODO I have to have this procedure, or I need to change
>> my/sanitize
>> +;; procedure.
>> +(define (my-file-exists? file)
>> +  (and (string? file)
>> +       (access? file F_OK)))
> Does file-exists? not work for you?

The file-exists? function causes my-sanitize function to break. I think. If you
get rid of it, then what happens when a user types in (file 4), you get an
raise-exception. I can probably just rework my-sanitizer function to deal with
that possibility, but I have not yet. I would love some guidance on how to do
that. Because I feel like having to handle that exception is hard.

>
>> +;; This procedure takes in a var and a list of procedures.  It loops
>> through
>> +;; list of procedures passing in var to each.
>> +;; if one procedure returns #t, the function returns true. 
>> Otherwise #f.
>> +;; TODO for fun rewrite this using map
>> +;; If I rewrote it in map, then it may help with sanitizing.
>> +;; eg: I could then potentially easily sanitize vars with lambda
>> procedures.
>> +(define (is-value-right-type? var list-of-procedures record
>> fieldname)
>> +  (if (null? list-of-procedures)
>> +      #f
>> +      (if ((car list-of-procedures) var)
>> +          #t
>> +          (is-value-right-type? var (cdr list-of-procedures) record
>> +                                fieldname))))
> Alternatively, (any (cut <> var) list-of-procedures).

You mentioned that in the last review, I just can't figure out how to use your
suggestion. This is the code that I have in the task list WIP:

*** TODO simplify my sanitizing funcions  (any (cut <> var))

#+BEGIN_SRC scheme
(use-modules (ice-9 curried-definitions)
             (srfi srfi-26))

(define (((expect-any predicates) record field) var)
  (if (any (cut <> var) predicates)
      var
      (begin
        ;; code code code
        ;; how do I tell the user which function failed?
        (display "error")
        (throw 'bad! var))))

;; here is how you use it.
  (name opensmtpd-table-name ;; string
        (default #f)
        (sanitize (lambda (var)
                    (((expect-any (list string? number?)) "hello" "that") var))))

#+END_SRC

Does that look close to what you want? I feel like it is way off, but I don't
know. Honestly when I say this suggestion I was completely blown away, I have
been using (any ) and (every) in a few places to get rid of some uses of
primitive eval.

>
>> +;; converts strings like this:
>> +;; "apple, ham, cherry" -> "apple, ham, or cherry"
>> +;; "pineapple" -> "pinneapple".
>> +;; "cheese, grapefruit, or jam" -> "cheese, grapefruit, or jam"
>> +(define (add-comma-or string)
>> +  (define last-comma-location (string-rindex string #\,))
>> +  (if last-comma-location
>> +      (if (string-contains string ", or" last-comma-location)
>> +          string
>> +          (string-replace string ", or" last-comma-location
>> +                          (+ 1 last-comma-location)))
>> +      string))
>> +
>> +
>> +(define (list-of-procedures->string procedures)
>> +  (define string
>> +    (let loop ((procedures procedures))
>> +      (if (null? procedures)
>> +          ""
>> +          (begin
>> +            (string-append
>> +             (cond ((eq? false? (car procedures))
>> +                    "#f, ")
>> +                   ((eq? boolean? (car procedures))
>> +                    "a boolean, ")
>> +                   ((eq? string? (car procedures))
>> +                    "a string, ")
>> +                   ((eq? integer? (car procedures))
>> +                    "an integer, ")
>> +                   ((eq? list-of-strings? (car procedures))
>> +                    "a list of strings, ")
>> +                   ((eq? assoc-list? (car procedures))
>> +                    "an association list of strings, ")
>> +                   ((eq? nested-list? (car procedures))
>> +                    "a nested-list of strings, ")
>> +                   ((eq? opensmtpd-pki? (car procedures))
>> +                    "an <opensmtpd-pki> record, ")
>> +                   ((eq? opensmtpd-table? (car procedures))
>> +                    "an <opensmtpd-table> record, ")
>> +                   ((eq? list-of-opensmtpd-match? (car procedures))
>> +                    "a list of unique <opensmtpd-match> records, ")
>> +                   ((eq? list-of-strings-or-gexps? (car procedures))
>> +                    "a list of strings or gexps, ")
>> +                   ;; TODO can I remove the next two procedures?
>> +                   ;; tables-data-are-a* ?  I think I can.
>> +                   ((eq? tables-data-are-assoc-list? (car
>> procedures))
>> +                    (string-append
>> +                     "an <opensmtpd-table> record whose fieldname
>> 'data' are "
>> +                     "an assoc-list.\nFor example: (opensmtpd-table 
>> "
>> +                     "(name \"hostnames\") , "
>> +                     "(data '((\"124.394.23.1\" . \"gnu.org\"))))"))
>> +                   ((eq? tables-data-are-a-list-of-strings?
>> +                         (car procedures))
>> +                    (string-append
>> +                     "on <opensmtpd-table> record whose fieldname
>> 'data' is "
>> +                     "a list of strings.\n"
>> +                     "For example: (opensmtpd-table (name
>> \"domains\") , "
>> +                     "(data (list \"gnu.org\" \"guix.gnu.org\")))"))
>> +                   ((eq? my-file-exists? (car procedures))
>> +                    "a file, ")
>> +                   (else "has an incorrect value, "))
>> +             (loop (cdr procedures)))))))
>> +  (add-comma-or (string-append (string-drop-right string 2) ".\n")))
> (define (procedure->string) ...)
> (define (procedures->string list)
>   (define strings (map procedure->string list))
>   (string-append
>    (string-join (drop-right strings 1) ", ")
>    (if (> (length list) 1) ", or")
>    (last strings)
>    ".\n"))
>
>> +(define (list-of-strings-or-gexps? list)
>> +  (and (list? list)
>> +       (cond ((null? list)
>> +              #t)
>> +             ((or (string? (car list))
>> +                  (gexp? (car list))
>> +                  (local-file? (car list))
>> +                  (file-append? (car list))
>> +                  (plain-file? (car list))
>> +                  (computed-file? (car list))
>> +                  (program-file? (car list)))
>> +              (list-of-strings-or-gexps? (cdr list)))
>> +             (else #f))))
>> +
>> +(define (my/sanitize var record fieldname list-of-procedures)
>> +  (define try-string
>> +    (string-append "Try " (list-of-procedures->string list-of-
>> procedures)))
>> +  (if (is-value-right-type? var list-of-procedures record fieldname)
>> +      var
>> +      (begin
>> +        (cond ((string? var)
>> +               (report-error (G_ "(~a \"~a\") is invalid.~%")
>> fieldname var))
>> +              ((or (number? var) (boolean? var))
>> +              (report-error (G_ "(~a ~a) is invalid.~%") fieldname
>> var) )
>> +              (else
>> +               (report-error (G_ "(~a ...) is invalid.~%Value is:
>> ~a~%")
>> +                             fieldname var)))
>> +        (display-hint (G_ try-string))
>> +        (throw 'bad! var))))
> This procedure needs a proper name, like sanitize/check-type, but more
> importantly, why not simply use define-configuration?

Yes! I have slowly been realizing that I have been clumsily re-inventing
define-configuration. I hope to switch to define-configuration, because a lot of
this code would go away. But I need to explore how define-configuration works.
That would be quite a major change. :)

>
>
> Cheers




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH opensmtpd-records v3] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-12-28  0:16         ` Joshua Branson via Guix-patches via
@ 2022-12-28 20:04           ` Liliana Marie Prikler
  2022-12-28 20:42           ` jbranso--- via Guix-patches via
  1 sibling, 0 replies; 23+ messages in thread
From: Liliana Marie Prikler @ 2022-12-28 20:04 UTC (permalink / raw)
  To: Joshua Branson; +Cc: Joshua Branson, 56046

Am Dienstag, dem 27.12.2022 um 19:16 -0500 schrieb Joshua Branson:
> Are you giving me a triple A+ ? :) Org generated the the like that. I
> think you mentioned that I should use fractions last time. Sorry I
> did not do that.
Do you have to convert your documentation from org?  Writing Texinfo
code manually is an option, as is generating it from define-
configuration IIRC.  There is also nothing wrong with manually touching
up generated docs, but I imagine doing so consistently might be a bit
more adventurous.

> If I wait 'til I implement every one of your suggestions, I will
> probably never submit it. I am really probably "perfecting" this
> service.
You can submit whatever, but don't expect me or any other committer to
upstream the patches while there are open points to address.
> 

> > Instead of a string, take 'no-verify as symbol perhaps?
> 
> Sounds good to me. May I ask why you prefer a symbol instead of a
> string?
Symbols can be compared with eq?, case et al.

> > > -;;;
> > >  ;;; OpenSMTPD.
> > >  ;;;
> > > +;;; This next bit of code helps me create my own sanitizer
> > > functions.
> > > +
> > > +;; some fieldnames have a default value of #f, which is ok. 
> > > They
> > > cannot have
> > > +;; a value of #t.
> > > +;; for example opensmtpd-table-data can be #f, BUT NOT true.
> > > +;; my/sanitize procedure tests values to see if they are of the
> > > right kind.
> > > +;; procedure false? is needed to allow fields like 'values' to
> > > be
> > > blank,
> > > +;; (empty), or #f BUT also have a value like a list of strings.
> > Use less egocentric comments ;)
> 
> I'm not sure what you mean here? I know I had a comment in my task
> list that said something like my sanitizer function are probably
> better than those found in guix. Apologies for that.
For what it's worth, it definitely wasn't I. [1]

> > 
> > > +(define (false? var)
> > > +  (eq? #f var))
> > > +
> > > +;; TODO I have to have this procedure, or I need to change
> > > my/sanitize
> > > +;; procedure.
> > > +(define (my-file-exists? file)
> > > +  (and (string? file)
> > > +       (access? file F_OK)))
> > Does file-exists? not work for you?
> 
> The file-exists? function causes my-sanitize function to break.
Why?

> I think. 
Prove it.

> If you get rid of it, then what happens when a user types in (file
> 4), you get an raise-exception. 
(file-exists? "(file 4)") ; => #f

> I can probably just rework my-sanitizer function to
> deal with that possibility, but I have not yet. I would love some
> guidance on how to do that. Because I feel like having to handle that
> exception is hard.

From the Guile manual:

 -- Scheme Procedure: stat object [exception-on-error?]
 -- C Function: scm_stat (object, exception_on_error)
[...]
     If the optional EXCEPTION_ON_ERROR argument is true, which is the
     default, an exception will be raised if the underlying system call
     returns an error, for example if the file is not found or is not
     readable.  Otherwise, an error will cause ‘stat’ to return ‘#f’.

Now, in (ice-9 boot-9), file-exists? is defined (assuming posix) as

      (lambda (str)
        (->bool (stat str #f)))

Thus, I am pretty sure that no exception should be raised from the
check ;)

> > 
> > > +;; This procedure takes in a var and a list of procedures.  It
> > > loops
> > > through
> > > +;; list of procedures passing in var to each.
> > > +;; if one procedure returns #t, the function returns true. 
> > > Otherwise #f.
> > > +;; TODO for fun rewrite this using map
> > > +;; If I rewrote it in map, then it may help with sanitizing.
> > > +;; eg: I could then potentially easily sanitize vars with lambda
> > > procedures.
> > > +(define (is-value-right-type? var list-of-procedures record
> > > fieldname)
> > > +  (if (null? list-of-procedures)
> > > +      #f
> > > +      (if ((car list-of-procedures) var)
> > > +          #t
> > > +          (is-value-right-type? var (cdr list-of-procedures)
> > > record
> > > +                                fieldname))))
> > Alternatively, (any (cut <> var) list-of-procedures).
> 
> You mentioned that in the last review, I just can't figure out how to
> use your
> suggestion. This is the code that I have in the task list WIP:
> 
> *** TODO simplify my sanitizing funcions  (any (cut <> var))
> 
> #+BEGIN_SRC scheme
> (use-modules (ice-9 curried-definitions)
>              (srfi srfi-26))
> 
> (define (((expect-any predicates) record field) var)
>   (if (any (cut <> var) predicates)
>       var
>       (begin
>         ;; code code code
>         ;; how do I tell the user which function failed?
>         (display "error")
>         (throw 'bad! var))))
All of them failed, that's the point.  As for constructing a string
from a list of procedures, see list-of-procedures->string.

> ;; here is how you use it.
>   (name opensmtpd-table-name ;; string
>         (default #f)
>         (sanitize (lambda (var)
>                     (((expect-any (list string? number?)) "hello"
> "that") var))))
> 
> #+END_SRC
> 
> Does that look close to what you want? I feel like it is way off, but
> I don't know. Honestly when I say this suggestion I was completely
> blown away, I have been using (any ) and (every) in a few places to
> get rid of some uses of primitive eval.
I don't see that, but I do see functions that have been dropped still
mentioned in the ChangeLog.  Another hint at this patch being too
convoluted for its own sake ;)

> > This procedure needs a proper name, like sanitize/check-type, but
> > more importantly, why not simply use define-configuration?
> 
> Yes! I have slowly been realizing that I have been clumsily re-
> inventing define-configuration. I hope to switch to define-
> configuration, because a lot of this code would go away. But I need
> to explore how define-configuration works.
> That would be quite a major change. :)
Manchmal erspart einem monatelange Implementier-Arbeit einen Nachmittag
in der Bücherei.

Cheers

[1] https://issues.guix.gnu.org/issue/56046#4-lineno323




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH opensmtpd-records v3] services (opensmtpd): add opensmtpd records to enhance opensmtpd-configuration.
  2022-12-28  0:16         ` Joshua Branson via Guix-patches via
  2022-12-28 20:04           ` Liliana Marie Prikler
@ 2022-12-28 20:42           ` jbranso--- via Guix-patches via
  1 sibling, 0 replies; 23+ messages in thread
From: jbranso--- via Guix-patches via @ 2022-12-28 20:42 UTC (permalink / raw)
  To: Liliana Marie Prikler; +Cc: Joshua Branson, 56046

December 28, 2022 3:04 PM, "Liliana Marie Prikler" <liliana.prikler@gmail.com> wrote:

> Am Dienstag, dem 27.12.2022 um 19:16 -0500 schrieb Joshua Branson:
> 
>> Are you giving me a triple A+ ? :) Org generated the the like that. I
>> think you mentioned that I should use fractions last time. Sorry I
>> did not do that.
> 
> Do you have to convert your documentation from org? Writing Texinfo
> code manually is an option, as is generating it from define-
> configuration IIRC. There is also nothing wrong with manually touching
> up generated docs, but I imagine doing so consistently might be a bit
> more adventurous.

I wrote the first draft of the documentation in org.  Then converted it
to texinfo.  I have been writing in texinfo ever since.  :)

> 
>> If I wait 'til I implement every one of your suggestions, I will
>> probably never submit it. I am really probably "perfecting" this
>> service.
> 
> You can submit whatever, but don't expect me or any other committer to
> upstream the patches while there are open points to address.

Of course.  :)  I wish I could implement all of your suggestions sooner, 
but I am still learning.  And I might be a bit of a slow coder.  :(

>> Instead of a string, take 'no-verify as symbol perhaps?
>> 
>> Sounds good to me. May I ask why you prefer a symbol instead of a
>> string?
> 
> Symbols can be compared with eq?, case et al.
> 
>>> -;;;
>>> ;;; OpenSMTPD.
>>> ;;;
>>> +;;; This next bit of code helps me create my own sanitizer
>>> functions.
>>> +
>>> +;; some fieldnames have a default value of #f, which is ok. 
>>> They
>>> cannot have
>>> +;; a value of #t.
>>> +;; for example opensmtpd-table-data can be #f, BUT NOT true.
>>> +;; my/sanitize procedure tests values to see if they are of the
>>> right kind.
>>> +;; procedure false? is needed to allow fields like 'values' to
>>> be
>>> blank,
>>> +;; (empty), or #f BUT also have a value like a list of strings.
>> Use less egocentric comments ;)
>> 
>> I'm not sure what you mean here? I know I had a comment in my task
>> list that said something like my sanitizer function are probably
>> better than those found in guix. Apologies for that.
> 
> For what it's worth, it definitely wasn't I. [1]
> 
>>> +(define (false? var)
>>> +  (eq? #f var))
>>> +
>>> +;; TODO I have to have this procedure, or I need to change
>>> my/sanitize
>>> +;; procedure.
>>> +(define (my-file-exists? file)
>>> +  (and (string? file)
>>> +       (access? file F_OK)))
>> Does file-exists? not work for you?
>> 
>> The file-exists? function causes my-sanitize function to break.
> 
> Why?
> 
>> I think.
> 
> Prove it.

Oh, the last time I used guile's file-exist? It broke a one of 
my tests.  I intend to use guile's file-exist? I just have not
figured out how to yet.  :)

> 
>> If you get rid of it, then what happens when a user types in (file
>> 4), you get an raise-exception.
> 
> (file-exists? "(file 4)") ; => #f

The way I am sanitizing it, something like this happens.  
A silly user puts this in their configuration:

(opensmtpd-configuration
   (config-file 4))


(file-exists? (openstmtpd-configuration-config-file record))

(file-exists? 4)  => raise-exception

>> I can probably just rework my-sanitizer function to
>> deal with that possibility, but I have not yet. I would love some
>> guidance on how to do that. Because I feel like having to handle that
>> exception is hard.
> 
> From the Guile manual:
> 
> -- Scheme Procedure: stat object [exception-on-error?]
> -- C Function: scm_stat (object, exception_on_error)
> [...]
> If the optional EXCEPTION_ON_ERROR argument is true, which is the
> default, an exception will be raised if the underlying system call
> returns an error, for example if the file is not found or is not
> readable. Otherwise, an error will cause ‘stat’ to return ‘#f’.
> 
> Now, in (ice-9 boot-9), file-exists? is defined (assuming posix) as
> 
> (lambda (str)
> (->bool (stat str #f)))
> 
> Thus, I am pretty sure that no exception should be raised from the
> check ;)
> 
>>> +;; This procedure takes in a var and a list of procedures.  It
>>> loops
>>> through
>>> +;; list of procedures passing in var to each.
>>> +;; if one procedure returns #t, the function returns true. 
>>> Otherwise #f.
>>> +;; TODO for fun rewrite this using map
>>> +;; If I rewrote it in map, then it may help with sanitizing.
>>> +;; eg: I could then potentially easily sanitize vars with lambda
>>> procedures.
>>> +(define (is-value-right-type? var list-of-procedures record
>>> fieldname)
>>> +  (if (null? list-of-procedures)
>>> +      #f
>>> +      (if ((car list-of-procedures) var)
>>> +          #t
>>> +          (is-value-right-type? var (cdr list-of-procedures)
>>> record
>>> +                                fieldname))))
>> Alternatively, (any (cut <> var) list-of-procedures).
>> 
>> You mentioned that in the last review, I just can't figure out how to
>> use your
>> suggestion. This is the code that I have in the task list WIP:
>> 
>> *** TODO simplify my sanitizing funcions  (any (cut <> var))
>> 
>> #+BEGIN_SRC scheme
>> (use-modules (ice-9 curried-definitions)
>> (srfi srfi-26))
>> 
>> (define (((expect-any predicates) record field) var)
>> (if (any (cut <> var) predicates)
>> var
>> (begin
>> ;; code code code
>> ;; how do I tell the user which function failed?
>> (display "error")
>> (throw 'bad! var))))
> 
> All of them failed, that's the point. As for constructing a string
> from a list of procedures, see list-of-procedures->string.
> 
>> ;; here is how you use it.
>> (name opensmtpd-table-name ;; string
>> (default #f)
>> (sanitize (lambda (var)
>> (((expect-any (list string? number?)) "hello"
>> "that") var))))
>> 
>> #+END_SRC
>> 
>> Does that look close to what you want? I feel like it is way off, but
>> I don't know. Honestly when I say this suggestion I was completely
>> blown away, I have been using (any ) and (every) in a few places to
>> get rid of some uses of primitive eval.
> 
> I don't see that, but I do see functions that have been dropped still
> mentioned in the ChangeLog. Another hint at this patch being too
> convoluted for its own sake ;)

How would I unconvoluted it?  Use define-configuration?  

> 
>> This procedure needs a proper name, like sanitize/check-type, but
>> more importantly, why not simply use define-configuration?
>> 
>> Yes! I have slowly been realizing that I have been clumsily re-
>> inventing define-configuration. I hope to switch to define-
>> configuration, because a lot of this code would go away. But I need
>> to explore how define-configuration works.
>> That would be quite a major change. :)
> 
> Manchmal erspart einem monatelange Implementier-Arbeit einen Nachmittag
> in der Bücherei.
> 
> Cheers
> 
> [1] https://issues.guix.gnu.org/issue/56046#4-lineno323




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration.
  2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
                   ` (4 preceding siblings ...)
  2022-12-23 16:39 ` [bug#56046] [PATCH opensmtpd-records v4 fixing charset=y error] " Joshua Branson via Guix-patches via
@ 2023-06-15 16:06 ` Vivien Kraus via Guix-patches via
  2023-08-18 11:16   ` Joshua Branson via Guix-patches via
  5 siblings, 1 reply; 23+ messages in thread
From: Vivien Kraus via Guix-patches via @ 2023-06-15 16:06 UTC (permalink / raw)
  To: 56046

Hello guix,

I would very much like to have better support (more modular) for
opensmtpd. This patch series seems to go in the right direction. What
is its status?

Best regards,

Vivien




^ permalink raw reply	[flat|nested] 23+ messages in thread

* [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration.
  2023-06-15 16:06 ` [bug#56046] [PATCH] services: mail: " Vivien Kraus via Guix-patches via
@ 2023-08-18 11:16   ` Joshua Branson via Guix-patches via
  0 siblings, 0 replies; 23+ messages in thread
From: Joshua Branson via Guix-patches via @ 2023-08-18 11:16 UTC (permalink / raw)
  To: Vivien Kraus; +Cc: Tobias Geerinckx-Rice, 56046

Vivien Kraus <vivien@planete-kraus.eu> writes:

> Hello guix,
>
> I would very much like to have better support (more modular) for
> opensmtpd. This patch series seems to go in the right direction. What
> is its status?
>
> Best regards,
>
> Vivien

So, I recently just got my email server up and running again, which is
awesome!  What is its status?

It works!  You can configure fairly basic email configurations.  You
should try to run it on your server.  This blog post walks you through how:

https://gnucode.me/submitting-opensmtpd-service-to-guixrus.html

You might not be able to use guix deploy with this service at the
moment.  You might have to ssh into your server and do a "guix system
reconfigure".  I fixed that bug, but have not pushed it to guixrus yet.

Feel free to ask me any questions.

In terms of upstreaming this to guix proper.  It seems like I should
* convert all of the (define-record-type* ...) -> (define-configuration)
* make sure all of the tests still work:
https://notabug.org/jbranso/guix/src/newOpensmtpdBranch/gnu/tests/mail.scm
* try to generate Tobias' smtpd.conf
* host a guix system is awesome party


There's a ton more in the task here:
https://notabug.org/jbranso/linode-guix-system-configuration/src/master/opensmtpd.org

Joshua






^ permalink raw reply	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2023-08-18 11:47 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-06-17 21:46 [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
2022-06-17 21:54 ` [bug#56046] [PATCH] gnu: services: opensmtpd-records-task-list.org: Some notes about how I thought about building this service. And some additional task lists, as well as the WIP documentation Joshua Branson via Guix-patches via
2022-07-04 21:17 ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration. Version 2 Joshua Branson via Guix-patches via
2022-07-06  4:27   ` Liliana Marie Prikler
2022-07-06 21:51   ` jbranso--- via Guix-patches via
2022-07-07  4:25     ` Liliana Marie Prikler
2022-07-07 17:27     ` jbranso--- via Guix-patches via
2022-07-07 18:20       ` Liliana Marie Prikler
2022-07-08  3:06         ` [bug#56046] [PATCH] services: mail: add opensmtpd records to enhance opensmtpd-configuration Joshua Branson via Guix-patches via
2022-07-12 15:45           ` Joshua Branson via Guix-patches via
2022-07-12 16:38             ` Joshua Branson via Guix-patches via
2022-07-05 21:36 ` jbranso--- via Guix-patches via
2022-10-24 17:30 ` [bug#56046] [Patch master v2] services (opensmtpd): " Joshua Branson via Guix-patches via
2022-10-24 18:28   ` Liliana Marie Prikler
2022-12-23 13:52     ` [bug#56046] [PATCH opensmtpd-records v3] " Joshua Branson via Guix-patches via
2022-12-26 19:34       ` Liliana Marie Prikler
2022-12-28  0:16         ` Joshua Branson via Guix-patches via
2022-12-28 20:04           ` Liliana Marie Prikler
2022-12-28 20:42           ` jbranso--- via Guix-patches via
2022-10-24 22:18   ` [bug#56046] [Patch master v2] " jbranso--- via Guix-patches via
2022-12-23 16:39 ` [bug#56046] [PATCH opensmtpd-records v4 fixing charset=y error] " Joshua Branson via Guix-patches via
2023-06-15 16:06 ` [bug#56046] [PATCH] services: mail: " Vivien Kraus via Guix-patches via
2023-08-18 11:16   ` Joshua Branson via Guix-patches via

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