[Dovecot] Sieve Vacation for redirected email

[Steffen Kaiser]

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On Tue, 26 Mar 2013, Dave Gattis wrote:

> Our emails are redirected from the home office causing all vacation responses 
> to fail with, "discarding vacation response for implicitly delivered message; 
> no known (envelope) recipient address found in message headers".

=== headers from reply
Return-Path: <dave.gattis at domain-a.com>
X-Original-To: dave.gattis at domain-b.com
Delivered-To: dave.gattis at domain-b.com
Received: from spamcop.main.ch (spamcop.main.ch [83.144.241.40])
         by domain-b.com (Postfix) with ESMTP id 0E4E81C101DE
         for <dave.gattis at domain-b.com>; Tue, 26 Mar 2013 14:35:13 -0400 
(EDT)
Received: from ex.domain-a.com (ex.domain-a.com [83.144.240.35]) by
spamcop.main.ch with ESMTP id 0dP4XCjZrdDY5l1Q for
<dave.gattis at domain-b.com>; Tue, 26 Mar 2013 19:41:36 +0100 (CET)
Received: from EX2.domain-a.com ([fe80::acd3:8e53:bcb6:7a4%11]) by
  ex2.domain-a.com ([fe80::acd3:8e53:bcb6:7a4%11]) with Microsoft SMTP 
Server
id
  14.01.0355.002; Tue, 26 Mar 2013 19:39:54 +0100

From: Dave Gattis <friends at sender.com>
To: SUMACO Gattis Dave <dave.gattis at domain-a.com>
=====

You have two problems:

a) "no known (envelope) recipient address found in message headers" means, 
that the vacation :addresses list does not contain

dave.gattis at domain-a.com

because vacation probes the entries of the :addresses list against To and 
CC.

b) the messages are _resend_ not forwarded by spamcop.main.ch to your MTA. 
By doing so the original *envelope* sender address is lost, which is *not* 
the entry in "From:". Therefore vacation would send the reply to:

dave.gattis at domain-a.com

which is the return path per your excerpt. You could verify that by 
finding the envelope sender in the postfix logs, I guess; or by fixing a).

Actually, I'm not sure if pigeonhole can pick up the address to reply to 
from a mail header - I do not see any hints in the sample config. So, 
maybe, you need to ask spamcop.main.ch to preserve the return address.

Note: Changing the envelope sender is not bad by itself, it solves several 
problems with forwarding; a well-known MTA can do this, too: 
http://social.technet.microsoft.com/Forums/en-US/exchange2010/thread/8006eabb-3334-4ff1-89d6-d647088bec46 
, but you get other problems rewriting the sender address.

- -- 
Steffen Kaiser
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