Josef Liška schreef:
But it sends vacation messages with null envelope sender, which is in my opinion undesirable, because many vacation messages are caught in spam filters.
I think there could be same sender on envelope. In dovecot-sieve/src/sieve-cmu.c around line 380 is a call to smtp_client_open(src->addr, NULL, &f); NULL could be replaced with src->fromaddr
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Summary: I expect messages sent by vacation recipe should have envelope from same as user's e-mail address. This is then writen to Return-Path: header by receiving MTA
NULL envelope from is used, resulting (in my case) to Return-Path: <> rewriten by postfix to Return-Path: <MAILER-DAEMON> by receiving MTA Interesting. I've seen a very similar suggestion yesterday. However, as I explained in the previous post, the use of a non-null envelope from field is discouraged by the Sieve vacation RFC (5230) and also by a more generic RFC (3834) describing the do's and dont's regarding auto-responders:
http://www.dovecot.org/list/dovecot/2008-August/032799.html
It puzzles me why spam filters would reject messages with a <> return path, which is a very common an valid use of the SMTP protocol. What spam filter are we talking about anyway?
Regards,
Stephan.