Microsoft Exchange Server giving error 0x8004011D

I have an XP pro Sp2 machine that whenever it tries to connect to the exchange server it gives the following error:
Task ‘Microsoft Exchange Server’ reported error (0x8004011D) : ‘The server is not available. Contact your administrator if this condition persists.’

It is only on this one machine. I can log in with the accounts on any other machine. I can log in with Outlook Web Access from the problem machine. I am able to ping the exchange server from the problem machine by ip address and FQDN. I can ping the workstation from the server. I have tried reinstalling Office to no avail. Any suggestions you may have would be much appreciated.