User cannot send email

[sqw]

We have one user in our company who can send emails only to people on the same exchange server. We have 4 servers exchange 5.5 and he is running outlook 2000. He cannot send mail to any other exchange servers or externally but he can recieve mail fine. The error message recieved is"Unable to deliver the message due to a communications failure This system has been configured to reject your mail". We have tried - deleting profile and recreating it, recreating mailbox, rebooted server, and moving his account from one server to another all to no avail. If anyone has any ideas that would be great.
Thanks

 

[beerhunter2]

Have you tried setting up Outlook on a different computer for this person? Might be an Outlook configuration issue, or a DNS resolution issue with the TCP/IP protocol.

 

[sqw]

Tried that and it worked thanks it was just specific to the computer