Twice last week my Windows Small Business Server 2003 daily performance reports listed an error I haven't seen before. Specifically, it listed an MSExchangeTransport Event ID: 3015 error with a single occurrence. The occurrence in question was an email message sent to a user account at sbcglobal.net.
I researched the error, and most of the documentation I found indicated the issue required using WinRoute to track routing groups or a bad pointer record. I confirmed with the ISP (Time Warner) that the server's PTR and Reverse DNS records are properly configured. Further, the domain is not listed on any spam/block lists I could find. There really aren't any routing groups in place, that I'm aware of, because this is a simple SBS 2003 setup.
Other information indicated the Microsoft Exchange MTA Stacks may be the culprit (if it's stalled). So I checked the server's MTA Stacks service. It was Disabled. So I set it to Automatic and dismounted and mounted the Exchange store. I'm still unable to send email from this domain to Bellsouth.net email accounts.
Then today staff began experiencing difficulty sending email to Bellsouth.net addresses. Those messages generate the following DNR report:
The following recipient(s) cannot be reached:
Persons Name (email@example.com) on 5/22/2008 11:46 AM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
Are these errors related? Why might this server be experiencing Exchange routing/delivery issues out of the blue?