[rt-users] RT 3.8.2, Postfix, and external aliases

[Damon Miller]

Hi all.  I need a little guidance on a problem I'm having with RT 3.8.2
using Postfix as the MTA.



The issue is that replies are not sent from RT when an external alias is
used; these messages are identified as bounces because their
'Return-Path' header is empty.  Replies are sent without incident when
the actual address on the RT server is used.



I do not have control over the remote server's configuration (running
Microsoft Exchange).  I do have control over my own Postfix server.



The basic configuration is as follows:

helpdesk-support at provider.com  --  RT's queue address (for the Support
queue)

support at consumer.com  --  Remote alias used for convenience

The support at consumer.com address points to helpdesk-support at provider.com
by way of a "Distribution List" which contains only one "Contact", the
target address.  I'm told this is how one creates an alias on Exchange
without having to create a new mailbox.



When Postfix receives mail by way of the alias the headers look
something like this:

>From MAILER-DAEMON  Wed Feb  4 14:21:39 2009
Return-Path: <>
X-Original-To: testinstance-support at provider.com

[etc.]

I do see the original destination address further down but that's
expected since the message has to originate somewhere.



When Postfix receives mail sent to the actual local address, the headers
are more complete:

>From testaccount at gmail.com  Thu Feb  5 09:36:41 2009
Return-Path: <testaccount at gmail.com>
X-Original-To: helpdesk-support at provider.com



I realize this may be a Postfix question but I'm just not sure where to
start...  My understanding is that the local delivery agent is
responsible for setting the "Return-Path" and "From" headers but I
assumed Postfix would do that if necessary.  It is doing this for
messages sent directly to addresses.  The remote server is not setting
these headers; I verified by sniffing the SMTP session.



Any suggestions would be most appreciated.



Thanks very much,

Damon