Scratch that I found the culprit.... We didn't dual stack, but had the 6to4 tunnel on, so my fault.
It looks like Comcast just turned on rDNS for IPv6. Sincerely, Eric Tykwinski TrueNet, Inc. P: 610-429-8300 F: 610-429-3222 -----Original Message----- From: mailop [mailto:[email protected]] On Behalf Of [email protected] Sent: Friday, October 02, 2015 9:03 AM To: [email protected] Subject: [mailop] Comcast having any issues? We've got a few complaints from customers receiving bounce-backs from Comcast about rDNS. 554 resimta-po-13v.sys.comcast.net Comcast 2002:42fc:6009::42fc:6009 Comcast requires that all mail servers must have a PTR record with a valid Reverse DNS entry. Currently your mail server does not fill that requirement. For more information, refer to: http://postmaster.comcast.net/smtp-error-codes.php#554 As this is coming from our server, I know that the rDNS is there and correct so just wondering if anyone else is seeing issues? Sincerely, Eric Tykwinski TrueNet, Inc. P: 610-429-8300 F: 610-429-3222 _______________________________________________ mailop mailing list [email protected] http://chilli.nosignal.org/mailman/listinfo/mailop _______________________________________________ mailop mailing list [email protected] http://chilli.nosignal.org/mailman/listinfo/mailop
