I am trying to send an email to a friend of mine who has comcast as their email and I have yahoo. I get the following message when attempting to send an email:Reporting-MTA: dns;web1-a.imodules.com
Arrival-Date: Tue, 3 Oct 2006 13:20:32 -0500
Final-Recipient: rfc822;[email protected]
Diagnostic-Code: smtp;521-EHLO/HELO from sender 18.104.22.168 does
not map to web1-a.imodules.com in DNS
521-sending machine name must be provided as a fully
521-qualified domain via EHLO/HELO command.
521-see section 22.214.171.124 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:
I then clicked on the link for more info and it talked about configuring ptr records and rdns, which I have no idea how to do. Can anyone help me figure this out?