Original reporter describes it in detail: -------------- Configuration: * LANG=es_ES.UTF-8 * claws-mail-i18n package installed * "Translate header names" option enabled * ~/.claws-mail/extraheaderrc file not present * ~/.claws-mail/python-scripts/auto/compose_any file not present * Python module installed but not enabled Steps to trigger the bug: * Web browse to the Debian user Spanish mailing list, i.e. https://lists.debian.org/debian-user-spanish/2014/08/msg00000.html * Click on the link to reply to the list (mailto protocol) Claws-mail compose window appears. I've changed the recipient to my own address to no disturb the list, and the subject to "Prueba". Here are the headers of that mail. Please note the non-standard En-Respuesta-A header instead of In-Reply-To. -------------- You can see the whole headers on the URL above, just for completeness the wrong header appears as: En-Respuesta-A: <53DAF6C6.9030909@sophie.unam.mx> There's no need to really send the message, just queuing it and showing queue source message shows the bug (and any --compose "mailto:..." with an In-Reply-To header is enough to trigger it from command line, there's no need to visit that page :) I've been investigating a bit, but I don't see an obvious solution beyond stop translating that header, of course. The In-Reply-To header is correctly parsed and translated from the mailto: link into the compose window, but later is not turned back to it's In-Reply-To value. I suspect is just being treated as a custom added header because there's some functions which do not include it as a "standard" header, like compose_parse_header or compose_get_manual_headers_info in compose.c.
Changes related to this bug have been committed. Please check latest Git and update the bug accordingly. You can also get the patch from: http://git.claws-mail.org/ ++ ChangeLog 2017-01-17 13:44:02.576403989 +0100 http://git.claws-mail.org/?p=claws.git;a=commitdiff;h=64a91c27cbdc90ca6f5c9bad8eecc121ece389de Merge: 28214f6 c0505b8 Author: Colin Leroy <colin@colino.net> Date: Tue Jan 17 13:44:01 2017 +0100 Merge branch 'master' of file:///home/git/claws http://git.claws-mail.org/?p=claws.git;a=commitdiff;h=c0505b80f173768b393ba6f21f99889144f293f1 Author: wwp <wwp@free.fr> Date: Tue Jan 17 13:41:52 2017 +0100 Fix bug 3251, 'A translated In-Reply-To header is sent translated' by making sure we're always storing untranslated headers. Optimize and sanitize a bit the code around it, too.