SMTP working great, incoming messages are not delivered
Posted on 2003-11-20
We had quite a problem with spammers recently. Thanks to everyone that helped me, that has stopped dead in its tracks. We now have a new problem. When I send a message, it reaches its destination without any problem. However, when I attempt to send from a remote server to this one, the message does not ever reach this server.
For the SMTP settings, what I changed was turning off anonymous access and only allowing connections from the 192.168.0.0 subnet. I undid this for a few hours and thankfully we were not being used as a relay again, but a message I sent from both hotmail and netscape did not reach me, despite those settings being off. It's back to the way it was. I have reset the server, stopped and started the POP3 service, and even deleted and re-created the SMTP connector. As a last resort, I was going to unmount the store, backup the database, re-install exchange completely, then reconnect the mailboxes, but I don't want to go that route just quite yet.
We are running Windows 2000 Server, Service Pack 3. Microsoft Exchange Server 2000, Service Pack 3 as well. All the latest security related patches have been applied that I know of.
Local delivery, going from this domain to this domain, does not have a problem. I can send a message from myself to my boss and it's available in his inbox immediately. It's when I try to send from not this domain that I have a problem. Port 110 is open on the router, telnetting to 192.168.1.4 110 works fine. I have not tried to telnet to the port from outside as of yet.
Until I get the chance to run an external telnet test, is there any other kind of diagnostic I can perform to try to figure out why it isn't working?