Here'sanother bounce email: The original message was received at Tue, 11 Apr 2006 19:16:44 -0400 from localhost.localdomain [127.0.0.1] ----- The following addresses had permanent fatal errors ----- <xxxxxx at comcast.net> (reason: 521-EHLO/HELO from sender 71.31.91.127 does not map to localhost.localdomain in DNS) ----- Transcript of session follows ----- ... while talking to gateway-s.comcast.net.: >>> MAIL From:<apache at localhost.localdomain> SIZE=2176 <<< 521-EHLO/HELO from sender 71.31.91.127 does not map to localhost.localdomain in DNS <<< 521-sending machine name must be provided as a fully <<< 521-qualified domain via EHLO/HELO command. <<< 521-see section 4.1.1.1 and 4.1.4 of RFC 2821 <<< 521 521: Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mailserver does not fill that requirement. For more information, refer to: http://www.comcast.net/help/faq/index.jsp?faq=Email118405 554 5.0.0 Service unavailable