Unexpected behavior with sieve_vacation_to_header_ignore_envelope = yes

[Matthias Petermann]

Hello Stephan,

Am 03.03.2019 um 00:50 schrieb Stephan Bosch via dovecot:>
 >
 > Op 27/02/2019 om 13:30 schreef Matthias Petermann via dovecot:
 >> Hello,
 >>
 >> we face an issue with the vacation extension of pigeonhole. Our
 >> upstream mail server (from which we pull our E-Mails with POP3) uses
 >> SPF and performs a SRS re-write of the Return Path. Once the mail is
 >> processed via our local postfix, it is delivered via dovecot deliver
 >> (using the lda). When the recipient has a vacation rule enabled in
 >> sieve, the out-of-office note cannot be sent, as pigeonhole tries to
 >> use the Return-Path (which is not accepted as sender by the mail 
server).
 >>
 >> We are using the following dovecot / pigeonhole versions:
 >>
 >> dovecot-2.3.2.1
 >> dovecot-pigeonhole-0.5.2
 >>
 >> As of my understanding, the problem was addressed in pigeonhole
 >> version v0.4.21 by introducing the
 >> sieve_vacation_to_header_ignore_envelope setting. Anyway - even when
 >> this is set to "yes" pigeonhole still uses the Return-Path instead of
 >> the "From:" header which I had expected:
 >>
 >> Feb 27 13:22:26 mail dovecot:
 >> lda(customer)<48383><3o+yOQGBdlz/vAAAZU03Dg>: Error: sieve:
 >> msgid=<e081d2ba-21d5-c32b-3750-69fe0c8a76d2 at petermann-it.de>: failed
 >> to send vacation response to
 >> SRS0=gwGXg6ad=RC=petermann-it.de=matthias at example.com: <Sendmail
 >> program returned error> (temporary error)
 >>
 >> Are my expectations wrong or did I miss some precondition?
 >
 > That setting is only about the composition of the "To:" header for the
 > outgoing vacation message (it's in the name). It has nothing to do with
 > the RCPT TO envelope address used for that message. Why exactly do 
the > mail servers reject the vacation message (I am not too familiar 
with SRS).
Thanks for the clarification. In the postfix log, it states the 
following reason for rejection:

Mar  3 08:34:34 mail postfix/smtpd[28049]: NOQUEUE: reject: RCPT from 
unknown[10.0.0.2]: 550 5.1.1 
<SRS0=gwGXg6ad=RC=petermann-it.de=matthias at example.com>: Recipient 
address rejected: User unknown; from=<> 
to=<SRS0=gwGXg6ad=RC=petermann-it.de=matthias at example.com> proto=ESMTP 
helo=<mail>

So it seems that the RCPT TO is rejected because the server (relay) 
doesn't accept the SRS adress as recipient.

Is there any way to manipulate the RCPT TO from pigeonhole to match the 
To header? Seems like I have to look into postfix if there is a way to 
decode the RCTP TO. Unfortunately, I am still not too knowledgeable 
about SRS, but will try to find out more.

Best regards,
Matthias


-- 
Matthias Petermann <matthias at petermann-it.de>