David Bremner <david@tethera.net> writes:

> Thomas Schneider <qsx@chaotikum.eu> writes:
>
>> Hello list,
>>
>> I use notmuch with the Emacs frontend and multiple accounts.  I’d like
>> it to set the domain part of Message-Id header of any mail I compose to
>> something sensible, e.g. the FQDN of the host (which does not seem to be
>> easy, see [0]) or the domain part of the From header.
>
> There is some discussion on the wiki of using gnus-alias and
> message-templ with notmuch. The latter is more about setting headers.

Thanks for the pointer.  gnus-alias seems to work so far.  I also use it
to set the Fcc header to avoid duplicating address matches.

>>> I was thinking about setting message-user-fqdn based on the From header
>> in an appropriate hook, but I haven’t found yet where and how to do
>> this.
>
> There is notmuch-mua-send-hook (which by default just runs
> message-send-hook)

This seems to be run too late, so as for now, I use message-setup-hook
and always define the address I want to send as beforehand.

---
(add-hook 'message-setup-hook
	  (lambda ()
	    (make-local-variable 'message-user-fqdn)
	    (setq message-user-fqdn
		  (car (reverse (split-string
				 (car (mail-header-parse-address
				       (message-field-value "From")))
				 "@"))))))
---

Maybe I could add Message-ID to one of the headers added beforehand so
that I see what is generated.