Subject: Undelivered Mail Returned to Sender
From: [email-masked] (Mail Delivery System)
To: [email-masked]
Date: Fri, 8 Jun 2012 11:07:15 +0100 (BST)

This is the mail system at host admin1.sample.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
    cust1793-1.in.mailcontrol.com[208.87.233.190] said: 554 5.7.1 Message
    Rejected Class=size limit=15728640 Subclass=reject size=18571048 (in reply
    to end of DATA command)