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