Steps to reproduce:
1. view the mail, it crashes.

you can however create such an email with the attached shellscript. put in your email.

Stack trace:
Backtrace was generated from '/usr/bin/evolution-2.6'

Using host libthread_db library "/lib/tls/libthread_db.so.1".
[Thread debugging using libthread_db enabled]
[New Thread -1231894848 (LWP 18047)]
[New Thread -1298445392 (LWP 18060)]
[New Thread -1281143888 (LWP 18055)]
[New Thread -1272755280 (LWP 18054)]
[New Thread -1263535184 (LWP 18053)]
[New Thread -1255146576 (LWP 18051)]
[New Thread -1245197392 (LWP 18050)]
[New Thread -1236771920 (LWP 18048)]
0xb76d4231 in __waitpid_nocancel () from /lib/tls/libpthread.so.0

+ Trace 129948

Other information:
#!/bin/bash
(
printf 'ehlo localhost\r\n'
sleep 1
printf 'MAIL FROM: <somephonenumber@somesource.com>\r\n'
sleep 1
printf 'RCPT TO: <somebody@testdomain.com>\r\n' 
sleep 1
printf 'DATA\r\n'
sleep 1
printf 'Received: from onewbx1p.one.at (onewbx1p.one.at [81.3.220.4])\r
        by Mail.outgesourced.org (8.13.1/8.12.11) with ESMTP id l3AEbR9r005653\r
        for <somebody@testdomain.com>; Tue, 10 Apr 2007 16:37:27 +0200\r
Received: from onegzx1p.one.at ([10.238.251.14])\r
        by onewbx1p.one.at (8.13.7+Sun/8.13.7) with ESMTP id l3AEbXDk010304\r
        for <somebody@testdomain.com>; Tue, 10 Apr 2007 16:37:33 +0200 (MEST)\r
Received: from mms81.somesource.com ([192.168.249.73])\r
        by onegzx1p.one.at (8.13.7+Sun/8.13.4) with ESMTP id l3AEbgJs000318\r
        for <somebody@testdomain.com>; Tue, 10 Apr 2007 16:37:42 +0200 (MEST)\r
Received: by mms81.somesource.com (Multimedia IP message store 6.1.999.11) id 45F95D620004C36E for somebody@testdomain.com; Tue, 1
0 Apr 2007 16:36:44 +0200\r
Subject: [one at] test mms rewrite\r
To: somebody@testdomain.com\r
Mime-Version: 1.0\r
Content-Type: multipart/related; type="text/html"; \r
        boundary="----=_Part_547166_1622809.1176215803928"; start="<AAAA>"\r
Importance: Normal\r
X-Mms-Sender-Visibility: Show\r
X-MMS-Message-Type: MM4_forward.REQ\r
X-UID: 2217\r
Content-Length: 953\r
Message-ID: <6425465.1176215803930.JavaMail.mms@mms81.somesource.com>\r
Date: Fri, 11 Apr 2007 01:37:59 +0100\r
From: blalblabla somephonenumber@somesource.com\r
Return-Path: <somephonenumber/TYPE=PLMN@somesource.com>\r
\r
------=_Part_547166_1622809.1176215803928\r
Content-Type: text/html; name=html.html; charset=utf-8\r
Content-Transfer-Encoding: base64\r
Content-ID: <AAAA>\r
Content-Disposition: inline; filename=html.html\r
\r
PGh0bWw+Cgo8aGVhZD4KPG1ldGEgaHR0cC1lcXVpdj0iQ29udGVudC1MYW5ndWFnZSIgY29udGVu\r
dD0iZW4tdXMiPgo8bWV0YSBodHRwLWVxdWl2PSJDb250ZW50LVR5cGUiIGNvbnRlbnQ9InRleHQv\r
aHRtbDsgY2hhcnNldD13aW5kb3dzLTEyNTIiPgo8bWV0YSBuYW1lPSJHRU5FUkFUT1IiIGNvbnRl\r
bnQ9Ik1pY3Jvc29mdCBGcm9udFBhZ2UgNC4wIj4KPG1ldGEgbmFtZT0iUHJvZ0lkIiBjb250ZW50\r
PSJGcm9udFBhZ2UuRWRpdG9yLkRvY3VtZW50Ij4KPHRpdGxlPk1NUzwvdGl0bGU+CjwvaGVhZD4K\r
Cjxib2R5PgoKPHA+Jm5ic3A7PC9wPgo8cCBhbGlnbj0iY2VudGVyIj4KPHRhYmxlIGJvcmRlcj0i\r
MCI+PHRyPjx0ZCBjb2xzcGFuPSIxIj48aHIgY29sb3I9IjgxODFEQiI+PC90ZD48L3RyPjx0cj48\r
dGQgY29sc3Bhbj0iMSIgYWxpZ249ImNlbnRlciI+SWlpPC90ZD48L3RyPjx0cj48dGQgY29sc3Bh\r
bj0iMSI+PGhyIGNvbG9yPSI4MTgxREIiPjwvdGQ+PC90cj48L3RhYmxlPgo8L3A+Cgo8L2JvZHk+\r
Cgo8L2h0bWw+Cg==\r
------=_Part_547166_1622809.1176215803928--\r
.\r
'
sleep 1
printf 'quit\r\n'
)|nc 127.0.0.1 25