[Mailman-Users] Mailman + Exim + strange headers

[Sergio Durigan Junior]

Hi there,

I've recently set up Mailman on my server, which runs Exim as the MTA
(Debian).  Things worked almost like a charm, except for one little
detail: the messages' headers seem a little strange to me.  Take a look
at this example:

--8<---------------cut here---------------start------------->8---
Received: from localhost ([::1] helo=host.bla)
	by host.bla with esmtp (Exim 4.80)
	(envelope-from <list-bounces at list.bla>)
	id 1Wm4qV-0004Xb-2z; Sun, 18 May 2014 14:25:59 -0300
Received: from smtp.ble ([ANY.IP])
 by host.bla with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:256)
 (Exim 4.80) (envelope-from <user at ble>)
 id 1Wm4qU-0004XV-9S
 for list at list.bla; Sun, 18 May 2014 14:25:58 -0300
Received: from [ANY.IP] (helo=localhost)
 by smtp.ble with esmtpsa (TLSv1:AES128-SHA:128)
 (Exim 4.62) (envelope-from <user at ble>)
 id 1Wm4qO-0005mm-GQ
 for list at list.bla; Sun, 18 May 2014 14:25:52 -0300

[...]

References: <ref1> <ref2>
 <ref3>

[...]
--8<---------------cut here---------------end--------------->8---

As you can see, the first two "Received:" headers got messed up somehow,
and the lines are not being prefix by \t but by one single space char.
The same thing happens with the "References:", and all the other headers
below.

After some investigation (and lots of email back and forth), I decided
it is not Exim's fault, because it doesn't happen on situations when I
use Exim without Mailman, so maybe it is Mailman or some weird scenario
of Mailman + Exim modifying the e-mails without permission.

I am using Debian Wheezy (7.1), with Exim 4.80-7 and Mailman 2.1.15-1.
I can provide my configuration files for Mailman and Exim, but basically
what I did was to follow <http://www.exim.org/howto/mailman21.html>.

Any help is appreciated.  Thanks,

-- 
Sergio