I'm having a problem where some user's of my web site complains they're receiving empty e-mail messages. After comparing the content and e-mail header of their e-mails with the ones I get I'm leaning onto the conclusion that their mail server somehow changes the content. Spam filter or virus filter maybe? I can't pinpoint that any of them exists through their mail header though.
I've tested on GMail and Exchange 2010 with more-or-less the same header results.
Delivered-To: my.email@gmail.com
Received: by 10.60.80.68 with SMTP id p4csp162755oex;
Wed, 16 Jan 2013 05:01:10 -0800 (PST)
X-Received: by 10.112.25.70 with SMTP id a6mr591545lbg.117.1358341269727;
Wed, 16 Jan 2013 05:01:09 -0800 (PST)
Return-Path: <their@email.com>
Received: from sending.mail.server.com (sending.mail.server.com [212.212.212.212])
by mx.google.com with ESMTP id n2si11385089lbk.106.2013.01.16.05.01.08;
Wed, 16 Jan 2013 05:01:09 -0800 (PST)
Received-SPF: neutral (google.com: 193.15.255.103 is neither permitted nor denied by best guess record for domain of noreply@nibeuplink.com) client-ip=193.15.255.103;
Authentication-Results: mx.google.com;
spf=neutral (google.com: 193.15.255.103 is neither permitted nor denied by best guess record for domain of noreply@nibeuplink.com) smtp.mail=noreply@nibeuplink.com
X-AuditID: 0a0201f8-b7f646d000000e46-26-50f6a494a5ce
Received: from webserver (Unknown_Domain [192.168.7.111])
by sending.mail.server.com (Corporate mail) with SMTP id A2.B0.03654.494A6F05; Wed, 16 Jan 2013 14:01:08 +0100 (CET)
Message-ID: <B2.B0.03654.494A6F05@sending.mail.server.com>
MIME-Version: 1.0
From: "Web Service"
<their@email.com>
To: my.email@gmail.com
Date: 16 Jan 2013 14:01:07 +0100
Subject: The Subject
Content-Type: multipart/alternative;
boundary=--boundary_35_281f82f0-3971-4c42-a8e1-f56216afbefa
----boundary_35_281f82f0-3971-4c42-a8e1-f56216afbefa
Content-Type: text/plain; charset=iso-8859-1
Content-Transfer-Encoding: quoted-printable
The user seems to be using Exchange 2003 as a server and the message they receive uses a different boundary than my server seems to be generating. Therefore I think the e-mail has been reubilt somewhere at the user's side and at that time lost some of its content.
x-mimeole: Produced By Microsoft Exchange V6.5
Received: from their.last.mail.server.net ([10.150.128.35]) by
computer.corporate.net with Microsoft SMTPSVC(6.0.3790.4675); Tue, 15 Jan
2013 13:22:30 +0200
Content-Type: multipart/alternative;
boundary="----_=_NextPart_003_01CDF312.9B0E9F00"
Received: from another.of.their.mail.servers.net ([10.150.129.56]) by
their.last.mail.server.net with Microsoft SMTPSVC(6.0.3790.4675); Tue, 15 Jan
2013 12:22:30 +0100
Received: from mail.server.net (mumrelp001.nsn-inter.net
[93.183.13.135]) by another.of.their.mail.servers.net (8.12.11.20060308/8.12.11)
with ESMTP id r0FBMSDH026761 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA
bits=256 verify=OK) for <receiving.mail@address.com>; Tue, 15 Jan 2013
12:22:28 +0100
Received: from sending.mail.server.com (sending.mail.server.com [212.212.212.212]) by
mail.server.net (8.13.8/8.13.8) with ESMTP id r0FBMRBq001875 for
<receiving.mail@address.com>; Tue, 15 Jan 2013 12:22:27 +0100
Received: from webserver (Unknown_Domain [192.168.7.111]) by sending.mail.server.com
(Corporate mail) with SMTP id 30.F9.03654.3FB35F05; Tue, 15 Jan 2013 12:22:27
+0100 (CET)
Content-Class: urn:content-classes:message
Subject: The Subject
Date: Tue, 15 Jan 2013 13:22:26 +0200
Message-ID: <50.F9.03654.3FB35F05@sending.mail.server.com>
X-MS-Has-Attach:
X-MS-TNEF-Correlator:
Thread-Topic: The Subject
Thread-Index: Ac3zEpv+A9o/QUbWTMmfmvqg/aBDEg==
From: Web Service <their@email.com>
To: "Name of user" <receiving.mail@address.com>
MIME-Version: 1.0
------_=_NextPart_003_01CDF312.9B0E9F00
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
Is it common that e-mail messages gets rebuilt during transmit and what are the most common causes for this? How do you prevent this from happening?