Then the message generated by Gnus does not respect MIME conventions. The boundary string used for the top-level multipart is the same than the boundary string used for the innermost multipart (see below for the generated message). In real life, this problem pops up when I forward multipart messages and that at the same time I sign my forwarded message. This is quite annoying since recipients either cannot decode the message or do not see all the MIME parts, depending on how their mail reader deals with invalid messages. Here is the message generated by the above MML syntax (look at the 1st and 3rd MIME boundaries, they are identical): ------------------------->8---------------------------- From: sebastien.villemot@ens.fr To: sebastien.villemot@ens.fr Subject: Test Date: Wed, 29 Dec 2010 17:14:59 +0100 Message-ID: <874o9wh7y4.fsf@karaba.cepremap.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.2 (gnu/linux) MIME-Version: 1.0 Content-Type: multipart/signed; boundary="====-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --====-=-= Content-Type: multipart/mixed; boundary="==-=-=" --==-=-= Content-Type: message/rfc822 Content-Disposition: inline --====-=-= Content-Disposition: inline MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="====-=-=" Foo --====-=-=-- --==-=-=-- --====-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iEYEARECAAYFAk0bXoUACgkQvjfoAftu/4uUJQCgnqreoFOLp4gcH1X8txwYbb4Y wZsAoPkIlBBD+jXfILU48MCj/Noeu7+V =ePJz -----END PGP SIGNATURE----- --====-=-=-- ------------------------->8---------------------------- Thanks, In GNU Emacs 23.3.1 (x86_64-pc-linux-gnu, GTK+ Version 2.24.6) of 2011-09-09 on spike.0x539.de, modified by Debian Windowing system distributor `The X.Org Foundation', version 11.0.11101000 configured using `configure '--build' 'x86_64-linux-gnu' '--build' 'x86_64-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' '--libexecdir=/usr/lib' '--localstatedir=/var/lib' '--infodir=/usr/share/info' '--mandir=/usr/share/man' '--with-pop=yes' '--enable-locallisppath=/etc/emacs23:/etc/emacs:/usr/local/share/emacs/23.3/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.3/site-lisp:/usr/share/emacs/site-lisp:/usr/share/emacs/23.3/leim' '--with-crt-dir=/usr/lib/x86_64-linux-gnu' '--with-x=yes' '--with-x-toolkit=gtk' '--with-toolkit-scroll-bars' 'build_alias=x86_64-linux-gnu' 'CFLAGS=-DDEBIAN -g -O2' 'LDFLAGS=-g' 'CPPFLAGS='' Important settings: value of $LC_ALL: nil value of $LC_COLLATE: nil value of $LC_CTYPE: nil value of $LC_MESSAGES: nil value of $LC_MONETARY: nil value of $LC_NUMERIC: nil value of $LC_TIME: nil value of $LANG: fr_FR.UTF-8 value of $XMODIFIERS: nil locale-coding-system: utf-8-unix default enable-multibyte-characters: t Major mode: Article Minor modes in effect: server-mode: t shell-dirtrack-mode: t tooltip-mode: t mouse-wheel-mode: t menu-bar-mode: t file-name-shadow-mode: t global-font-lock-mode: t font-lock-mode: t blink-cursor-mode: t auto-encryption-mode: t auto-compression-mode: t column-number-mode: t line-number-mode: t transient-mark-mode: t Recent input: C-p C-p h n q M-g q m C-n C-n C-n C-n C-n C-y C-p C-p C-p C-p C-p C-p C-p C-a C-k C-k C-p C-p C-p C-p C-e s e b a s t i e n @ i v i l l e m o t . n a m e C-n o n x C-c C-c L 5 C-p C-u C-u g h M-x r e p o r t e m b u Recent messages: nnrss: Requesting Plone News...done nnrss: Requesting PhpBB announcements...done nnrss: Requesting GANDI News...done nnrss: Requesting Radio-Canada | Qu=e9bec...done nnrss: Requesting Radio-Canada | National...done nnrss: Requesting A la une =2013 le fil d'actualit=e9 de service-public.fr...done nnrss: Requesting Le blog de Jean-Luc M=e9lenchon...done nnrss: Requesting Le blog de Martine Billard...done Checking new news...done Making completion list... 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hides /usr/share/emacs/23.3/lisp/org/org-mouse /usr/share/emacs23/site-lisp/org-mode/org-attach hides /usr/share/emacs/23.3/lisp/org/org-attach /usr/share/emacs23/site-lisp/org-mode/org-id hides /usr/share/emacs/23.3/lisp/org/org-id /usr/share/emacs23/site-lisp/org-mode/org-docbook hides /usr/share/emacs/23.3/lisp/org/org-docbook /usr/share/emacs23/site-lisp/org-mode/org-feed hides /usr/share/emacs/23.3/lisp/org/org-feed /usr/share/emacs23/site-lisp/org-mode/org-freemind hides /usr/share/emacs/23.3/lisp/org/org-freemind /usr/share/emacs23/site-lisp/flim/sasl hides /usr/share/emacs/23.3/lisp/net/sasl /usr/share/emacs23/site-lisp/flim/ntlm hides /usr/share/emacs/23.3/lisp/net/ntlm /usr/share/emacs23/site-lisp/flim/hmac-def hides /usr/share/emacs/23.3/lisp/net/hmac-def /usr/share/emacs23/site-lisp/flim/hmac-md5 hides /usr/share/emacs/23.3/lisp/net/hmac-md5 /usr/share/emacs23/site-lisp/flim/sasl-ntlm hides /usr/share/emacs/23.3/lisp/net/sasl-ntlm /usr/share/emacs23/site-lisp/flim/sasl-digest hides /usr/share/emacs/23.3/lisp/net/sasl-digest /usr/share/emacs23/site-lisp/flim/sasl-cram hides /usr/share/emacs/23.3/lisp/net/sasl-cram /usr/share/emacs23/site-lisp/emms/tq hides /usr/share/emacs/23.3/lisp/emacs-lisp/tq Features: (shadow emacsbug reporter rmailmm rmail debian-bug help-mode view w3m-form w3m-symbol w3m w3m-hist w3m-e23 w3m-ccl ccl w3m-fsf w3m-favicon w3m-image w3m-proc w3m-util org-table org-wl org-w3m org-vm org-rmail org-mhe org-mew org-irc org-jsinfo org-infojs org-html org-exp ob-exp org-exp-blocks org-agenda org-info org-gnus org-docview org-bibtex bibtex org-bbdb org warnings ob-R ob-octave ob-emacs-lisp ob-tangle ob-ref ob-lob ob-table org-footnote org-src ob-comint ob-keys ob ob-eval org-pcomplete pcomplete org-list org-faces org-compat org-entities org-macs noutline outline easy-mmode cal-menu calendar cal-loaddefs vc-git make-mode tramp-imap tramp-gw tramp-fish tramp-smb tramp-cache tramp-ftp tramp-cmds tramp advice advice-preload tramp-compat trampver newcomment tabify man gnus-cite smiley ansi-color mail-extr gnus-async gnus-bcklg sort byte-opt bytecomp byte-compile gnus-ml disp-table gnus-demon gnus-topic nnrss mm-url parse-time timezone utf-7 utf7 starttls nnimap imap nndraft nnmh epa-file epa epg auth-source gnus-agent gnus-srvr gnus-score score-mode nnvirtual gnus-msg gnus-art mm-uu mml2015 epg-config mm-view smime dig nntp gnus-cache gnus-sum nnoo gnus-group gnus-undo nnmail mail-source format-spec gnus-start gnus-spec gnus-int gnus-range message sendmail ecomplete rfc822 mml mml-sec password-cache mm-decode mm-bodies mm-encode mail-parse rfc2231 rfc2047 rfc2045 qp ietf-drums mailabbrev gmm-utils mailheader canlock sha1 sha1-el hex-util hashcash gnus-win xml-weather help-fns edmacro kmacro derived xml cl cl-19 gnus-BTS windmove winner server ido gnus gnus-ems nnheader gnus-util netrc time-date mail-utils wid-edit cus-start cus-load debian-el debian-el-loaddefs w3m-load slime-autoloads org-install ess-toolbar ess-mouse mouseme thingatpt browse-url ess-menu ess-swv ess-noweb noweb-font-lock-mode ess-bugs-l essd-els ess-sas-d ess-sas-l ess-sas-a executable shell ess-arc-d ess-vst-d ess-xls-d ess-lsp-l ess-sta-d ess-sta-l cc-vars cc-defs make-regexp ess-sp6-d ess-sp5-d ess-sp3-d ess-r-d ess-r-args assoc ess-s-l ess-inf ess-utils comint ring ess-mode noweb-mode ess ess-custom regexp-opt easymenu ess-compat ess-site emms-auto dpkg-dev-el dpkg-dev-el-loaddefs tempo url url-proxy url-privacy url-expand url-methods url-history url-cookie url-util url-parse url-vars mm-util mail-prsvr mailcap xml-parse doxymacs bbdb-autoloads preview-latex tex-site auto-loads tooltip ediff-hook vc-hooks lisp-float-type mwheel x-win x-dnd font-setting tool-bar dnd fontset image fringe lisp-mode register page menu-bar rfn-eshadow timer select scroll-bar mldrag mouse jit-lock font-lock syntax facemenu font-core frame cham georgian utf-8-lang misc-lang vietnamese tibetan thai tai-viet lao korean japanese hebrew greek romanian slovak czech european ethiopic indian cyrillic chinese case-table epa-hook jka-cmpr-hook help simple abbrev loaddefs button minibuffer faces cus-face files text-properties overlay md5 base64 format env code-pages mule custom widget hashtable-print-readable backquote make-network-process dbusbind system-font-setting font-render-setting gtk x-toolkit x multi-tty emacs)