Can’t connect to one server

I have 3 Win 95 clients that cannot connect to just one of our servers (which happens to be the mail server). These clients can see every other server on the network however. When I ping the server, I get a “host not found” error. When I am at the server and try to ping the client, same problem.

I have tried all of the usual steps: reinstalled NIC driver, Networking protocols, replace NIC card and cables. I even tried to plug the machine into different port. I rebooted the server multiple times and rebuilt the WINS database.

Anyone have any suggestions or have similar problems?