Good Day: I have an interesting scenario that I am trying to get a handle on. There seems to be one domain from which random email messages are rejected when they are sent to our mail server. Nothing is held in the queue of our Edge server and I have the IP and domain name of the send domain set as allow on our Edge server. Any thoughts?

What does the NDR say?

This is the only NDR we receive, not very helpful: The e-mail system was unable to deliver the message, but did not report a specific reason. Check the address and try again. If it still fails, contact your system administrator.

Check so you have PTR records in place You can check and validate the smtp domain from www.mxtoolbox.com Jonas Andersson MCTS: Microsoft Exchange Server 2007/2010 | MCITP: EMA 2007/2010 | MCSE/MCSA Blog: http://www.testlabs.se/blog

Hi jwmms, 1. I would also let the sender side to analyze the smtp log to confirm the issue, and let the sender side to telnet your exchange edge server through their server to confirem whether it is work well. 2. May be the issue is caused by the sender side, also please the sender to check their PTR. 3. Confirm that all the IP not in the blacklist on the public. Regards! Gavin TechNet Subscriber Support in forum If you have any feedback on our support, please contact tngfb@microsoft.com Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

Thanks for the info; I will follow up on these matters. It may be that this is more of a sender error than a recipient error. Jesse