Subject: Undelivered Mail Returned to Sender
From: [email-masked] (Mail Delivery System)
To: [email-masked]
Date: Sat, 5 Feb 2011 18:18:03 +0000 (GMT)

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 mailspool.example.net[212.126.144.70] said:
    [email-masked] is not an active address at this host (invalid FreeUK
    550 username) (in reply to RCPT TO command)

Subject: foo
From: Julia Stevens <[email-masked]>
To: Fred Bloggs <[email-masked]>
Date: Sat, 5 Feb 2011 18:18:02 +0000

HTMl goes here.