Subject: Undelivered Mail Returned to Sender
From: [email-masked] (Mail Delivery System)
To: [email-masked]
Date: Wed, 28 Jul 2010 15:56:45 +0100 (BST)

This is the mail system at host server2.example.co.uk.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to <postmaster>

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<[email-masked]>: host mx1.example.net[213.8.161.228] said: 554 Rcpt
    <[email-masked]> does not exist (in reply to end of DATA command)