Just installed a new SBS 2003 server with SP2 (not R2) and I can't receive emails from external recipients. Here's a list of what I've been able to figure out so far...
1. Internal email works fine
2. External sent from another SBS server reports error 4.4.7 could not deliver in time specified
3. Gmail returns NDR saying my server did not accept request to connect.
4. IntoDNS reports all is setup fine except the Reverse DNS (ISP doing that today)
5. I can NOT telnet in on port 25 from outside the LAN, but internally i get good response
6. I put server in Maintenance mode and reinstalled everything except Exchange.
7. All of the standard SBS ports are open and pointing to the server.
8. NSLookup using multiple name servers looks good.
9. OpenDNS reports the right IP in their cache for mail.mydomain.com.
What's strange though...I try accessing my OWA from off LAN and I get an actual box that pops up asking for username/password instead of the OWA login page (internall it works). I try logging in using my admin or user account and I eventually get the following (401 Unauthorized. Your client does not have permission to get URL / from this server. ). So now I'm wondering if I'm dealing with 2 separate issues, or one in the same. I don't think the reverse DNS can be causing all of this, especially not the problem with the OWA. But maybe I'm wrong. I've poked around the SMTP Virtual server settings and everything looks fine (it's a fresh install). I'm not sure if the problem is there because the internal telnet got a good response and internal email works. I'm not as good with IIS so I don't know if the problem could be within there or not. I also cannot remote into the server using TermServ. When I call my ISP today I'm going to ask if they have any sort of weird settings on their end that may be blocking anything. It almost sounds to me its a firewall blockage issue, but all my ports are open. At this point I'm starting to go in circles so I decided it was time to post.