From: MAILER-DAEMON@smtp.unknown.com (Mail Delivery System)
Subject: Undelivered Mail Returned to Sender
To: sendinguser@unknown.com
Date: Tue, 27 Mar 2007 12:34:07 -0700 (PDT)

This is the mail system at host smtp.unknown.com.

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

<receivinguser@baddomain.net>: Validation error during Name Service lookup. Error 167 :
    VAL_UNTRUSTED_ANSWER  for name=baddomain.net type=MX

Reporting-MTA: dns; smtp.unknown.com
X-Postfix-Queue-ID: B3A0648DB2
X-Postfix-Sender: rfc822; sendinguser@unknown.com
Arrival-Date: Tue, 27 Mar 2007 12:34:06 -0700 (PDT)

Final-Recipient: rfc822; receivinguser@baddomain.net
Original-Recipient: rfc822;receivinguser@baddomain.net
Action: failed
Status: 5.4.3
Diagnostic-Code: X-Postfix; Validation error during Name Service lookup. Error
    167 : VAL_UNTRUSTED_ANSWER  for name=baddomain.net type=MX
