I've just got this bounce message back from hotmail, which seems to show that the email headers contain the users email address. I am the admin user for our site and my email is matt.gibson@mymoodle.com. the site is at http://moodle.mymoodle.com and the SMTP user is moodlenoreply@mymoodle.com, which is a user account on our exchange server.

Here is the bounce message

I'm afraid I had problems forwarding your message. Full details follow:

Subject: 'ok, no problem....'
Date: 'Sun, 7 Oct 2007 11:04:30 +0100'

1 error(s):

SMTP Server <mx1.hotmail.com> rejected sender <matt.gibson@pmymoodle.com> (Error following MAIL command). It
responded as follows: [msn.com]

I have also attached the mail's original headers. Sorry it didn't work out.

Here is the attached header:

Received: from 10.80.162.2 ([10.80.162.2])
by elc-ecc-mail-01.equinoxit.net with emfmta (version 3.3.0.3203.0.rd-3.2.2-libc2.3.1) vanilla id 1192021036
for students_email@msn.com; Sun, 07 Oct 2007 10:04:31 +0000
Received: from moodle.mymoodle.com ([192.168.1.253]) by exch1.SCHOOLDOMAIN.INTERNAL with Microsoft SMTPSVC(6.0.3790.1830);
Sun, 7 Oct 2007 11:04:31 +0100
Date: Sun, 7 Oct 2007 11:04:30 +0100
Return-Path: matt.gibson@mymoodle.com
To: Student <students_email@msn.com>
From: Matt Gibson <moodlenoreply@mymoodle.com>
Reply-to: Do not reply to this email <moodlenoreply@mymoodle.com>
Subject: ok, no problem....
Message-ID: <a12ae3917ba2f9d80e7046c21b695138@moodle.mymoodle.com>
X-Priority: 3
X-Mailer: PHPMailer [version Moodle 2007021520]
MIME-Version: 1.0
Content-Type: multipart/alternative;
boundary="b1_a12ae3917ba2f9d80e7046c21b695138"
X-OriginalArrivalTime: 07 Oct 2007 10:04:31.0148 (UTC) FILETIME=[743A36C0:01C808C9]