I have two identical terminal servers. Both run w2k, and office 2k, patched to the same level; our exchange server is running w2k, Exchange 2000.
When users on one terminal server quit outlook having added/changed/deleted an item in their calendar, they get the message
"Unable to update public free/busy data. Outlook can't find the mail service provider. To check your profile settings, double click the Mail icon in Windows control panel. Or, try to log on to your mail system again"
The appointment change is saved; there is no problem getting mail.
Now, the odd thing (apart from the unusual use of a comma in the last sentence of the error message) is that if these users connect to the other server, everything works fine. I've run outlook.exe /cleanfreebusy but am told "Unable to clean your free/busy information on the server." I've deleted the local cache of their profiles on the effected server, but that made no difference...