I've have an odd problem that is gotten me into some political trouble that I'd like very much to get out of.

I've got a dedicated server at 1&1 running Plesk 7.5 and qmail.
There are 5 domains, each with their own IP address.

Whenever any user on this box sends mail, the header includes a Received line that mentions one particular domain and its associative IP, which entirely unrelated.

Here is one such header.
(fake domain, fake ip)

Return-Path: <bibby@domain.org>
Delivered-To: 47-bibby@surfmerchants.com
Received: (qmail 24256 invoked from network); 28 Jan 2007 13:32:08 -0500
Received: from wrongdomain.org (HELO hosting1.surfmerchants.com) (
by hosting2.surfmerchants.com with (DHE-RSA-AES256-SHA encrypted) SMTP; 28 Jan 2007 13:32:08 -0500
Received: (qmail 6303 invoked from network); 28 Jan 2007 13:31:11 -0500
Received: from c-66-30-13-218.hsd1.ma.comcast.net (HELO ? (
by domain-A.org with SMTP; 28 Jan 2007 13:31:11 -0500
From: bibby@domain.org
To: bibby@surfmerchants.com
Date: Sun, 28 Jan 2007 13:30:27 -0500
MIME-Version: 1.0
Subject: test M-B

(domain.org is on hosting1
my mailbox @surfmerchants is on hosting2)

Now, domain.org's IP is *.89 , why is it reporting *.112 ?
Everything DNS-wise for this domain returns *.89, and reverse on *.89 returns domain.org.
So it's clearly not that, especially since it's happening to the three remaining domains as well.
Add to that, hosting1.surfmerchants.com is neither of these, it's *.115!

If qmail must include this line, and every domain on this machine has to report the same IP/domain, I'd like to at least change it. Can anyone help me do this?