Email Rejected by Comcast Share on Facebook Post on reddit Tweet on Twitter Share on LinkedIn Home › Forums › Messaging Software › Exchange 2000 / 2003 › Email Rejected by Comcast This topic has 3 replies, 3 voices, and was last updated 12 years, 12 months ago by gosavi. Viewing 1 post (of 1 total) Author Posts gosaviMember Sep 18, 2007 at 7:57 am #127812 We’re running Exchange 2000. We host our own email server behind a Netgear firewall. Most emails appear to be flowing fine. However, I’ve received 2 of these NDR’s today. Quote: The following recipient(s) could not be reached: ‘[email protected]’ on 9/17/2007 4:47 PM There was a SMTP communication problem with the recipient’s email server. Please contact your system administrator. I had a similar rejection notice from one other domain as well. I’ve done some searching and i think it may have something to do with Reverse DNS lookup. I’ve tried telnet to comcast and starting a mail conversation. At MAIL FROM: I get a 530 AUTHENTICATION REQUIRED message. I’m not sure how our Reverse DNS should look (I wasn’t the one that set it up) so I am sorta stumped at the moment. If anyone can shed some light for me I would appreciate it. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic.