One of our clients is having trouble sending email to certain domains.
We are running windows server 2003 and exchange sp2.
As far as I can see we have everything configured correctly - we have a fixed ip, our reverse dns corresponds correctly with our servers FQDN and everything else is working fine.
I have also checked our IP against blacklists using this tool:
Everyone seems ok (no listings).
However, they are getting emails bounce back when sent to certain domains.
As an initial test, I found the mx records for a particular problem domain, I pinged it from the server and from a remote machine (both returned the same ip, and response time seemed fine).
Then I telneted into the remote mail server, on a machine outside the company it connected without any problem, but from the server, it would not connect to the remote mail server - it just timed out.
Just wondering if this gives an indication of whats wrong, or what would the next troubleshooting steps be?