we are running Exchange 2013 with 3 server in a DAG. Mail was flowing fine and continues to flow properly within the severs of this DAG. I added a new Exchange 2013 server. It is Not a member of the DAG.
Mail to outside address flows properly.
Mail routed on this one new server, sent to an inside mailboxes located in the DAG, is queuing up on the DAG queue. The error message is 451 4.4.0 DNS query failed. The error was: DNS query failed with error ErrorRetry.
When I run Get-DatabaseAvailabilityGroup it resolves correctly.
I need to be able to get these mail to stop from stacking up and get delivered properly. Any thoughts?
Email ServersExchange
Last Comment
John Water
8/22/2022 - Mon
Simon Butler (Sembee)
Can you telnet to the IP address of the other servers correctly on port 25? Confirm connectivity first.
Simon.