We have Exchange 2007 on Windows 2003. All roles installed on 1 machine.
Some of our e-mails to specific domains are remaining in the queue for long time and then getting expired. I can telnet to the affected domain and I can send a test message. I confirmed with the recipient and he is receiving my message (sent through telnet).
Exchange is configured with a single send connector. Logging level is set to Verbose but no logs generated specific to the affected domain.
Even those e-mails are not hitting the firewall. As if they are not leaving the exchange server.
I tried using external DNS servers on send connector but no luck.
I followed the steps described in the similar posts on Expert-Exchange but no benefit.
Any ideas what else could cause the problem??