unroutable mail error....

outgoing smtp problem via Outlook (smtp authentication is enabled as well)

This happened in the past and its annoying...

Steps taken:
off - "Track the origin of messages sent though the mail server "
off - "prevent pop3 flood..."
on - "Silently Discard all FormMail-clone "
on - "Include a list of Pop before SMTP senders in the X-PopBeforeSMTP "
on - mailman

Exim configurator:
off - "Always set the Sender: header when the sender is changed from the actual sender"
on - verify sender
off -"Discard emails for users who have exceeded their quota instead of keeping them in the queue"

/scripts/exim4 --force
/scripts/fixcommonproblems

How do I correct this issue?

Version: cPanel 10.x R-85

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mail delivery error
=====

This message was created automatically by mail delivery software.

A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed:

email@msn.com
unrouteable mail domain "msn.com"

------ This is a copy of the message, including all the headers. ------

Return-path: <misc@thedomain.com>
Received: from c-24-15-135-203.client.comcast.net ([24.15.135.203] helo=angel)
by server.serverdomain.com with esmtpa (Exim 4.44)
id 1D0Iq5-00019a-R9
for email@msn.com; Sun, 13 Feb 2005 07:27:02 -0500
Message-ID: <3824-22005201312273515@angel>
From: "Test Email" <misc@thedomain.com>
To: "First Last Name" <email@msn.com>
Subject: change of email address
Date: Sun, 13 Feb 2005 06:27:03 -0600
MIME-Version: 1.0
Content-type: text/plain; charset=windows-1252
Content-Transfer-Encoding: quoted-printable