Dnia 18.09.2021 o godz. 08:39:41 Vladimir Mishonov pisze:
2. While the above is mostly for aesthetical reasons, there is one
other thing: the templates for mailer-daemon messages have obsolete
"From" and "To" header formats, e.g.:
From: mailer-dae...@mydomain.com (Mail Delivery System)
To: postmas...@mydomain.com (Postmaster)
This appears to be the legacy RFC5322 header format (see
https://github.com/roundcube/roundcubemail/issues/5402). I'm not
very well versed in the RFC stuff, but what I can say for sure is
that so far I've ONLY seen this format in these templates, and
nowhere else. It looks like some email clients (like Roundcube, see
the link above) do not handle this format very well, probably for
the reason that it's barely used nowadays, if at all.
From the very link you quoted, you can know that this format is still used
and can be still seen in the regular emails you get, because (quote from
your link):
"at least two current programs use this syntax:
The MUA called ELM, and the unix tool to send email from the command line
(often used by cron jobs): mailx."
Wouldn't it be better to patch Roundcube? Also from the link you quoted, the
developers say they'll accept a patch. Someone even tried to submit a patch,
but failed. It shouldn't be too hard to patch however. If I were you, I
would rather try to patch Roundcube and not Postfix.
Postfix. I understand that I can make changes to the source code and
recompile the program, but even if I am able to accomplish this, it
would only be half of the job done, if not even less than that. I'd
also have to arrange a process to create packages in the appropriate
format for my OS distribution and keep them updated.
You don't have to. You can get rid of packaged Postfix and use the
one installed from source. Of course everytime new Postfix version is
released, if you want to upgrade, you need to download the new source
version, apply your patch and recompile. You can try to automate that :).
But again, if I were you, I would rather go towards modifying Roundcube. It
would be probably easier, and that's actually the place where the error is,
so it should be fixed there, not worked around in Postfix, because you can
get emails with headers in this forma from other sources too, as noted
above.
The postconf(5) manual says
that postmaster notifications generated by smtp and smtpd _can_ be
inspected by adding "notify" to "internal_mail_filter_classes".
Unfortunately, while it does seem to enable DKIM signing for them
(via the milter application that I've configured), it still does not
apply any header checks to them.
If you are able to apply a milter to them, you can write a milter that
rewrites those headers.
