Subject: Undelivered Mail Returned to Sender
From: [email-masked] (Mail Delivery System)
To: [email-masked]
Date: Sun, 23 Oct 2011 00:05:53 +0100 (BST)

This is the mail system at host admin1.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 mailgate.test.com[217.158.5.8]
    said: 554 Spam email. Email Session ID: {4EA34C51-0-5059ED9-FFFF} (in reply
    to end of DATA command)

Subject: foo
From: John Smith <[email-masked]>
To: [email-masked], [email-masked]
Date: Sun, 23 Oct 2011 00:05:53 +0100

Text