One of our customers is having a problem with their Exchange server. Their network is distributed between three buildings. (They are all about 100 feet apart and have cable run to each of them.) One of the buildings has all three of their servers (ASD1 is their PDC and MAS200 server, ASD2 is their backup server, and EXCHANGE is their Exchange server.)

In one of the other buildings is a computer that user JOHNQ uses. Upon trying to setup johnq's Exchange account we encounter this problem. went to the Mail applet in control panel and proceeded to setup the Exchange account. specified the correct name of the Exchange server, and types in johnq as the user. When we click on the "check name" button, the computer just kind of hangs there. After a while we try ctrl+alt+del and find that the mail setup is not responding. we close it, and then this message appears:

The Microsoft Exchange server is not responding.

This same problem occurs on another machine in the building. (Though I this machine's user is still able to access her email.) The problem does NOT occur in another building. Regardless, johnq's computer can still access the network just fine, including the computer named EXCHANGE!

I checked to ensure that all services on the Exchange server are running. We then rebooted the Exchange server to no avail. Any ideas on what could be going on here?