We are having an interesting problem with a few of our users. We are a combined Exchange 2003/2010 environment. In the process of deploying 2010, so most user's mailboxes are still on the 2003 servers. We recently migrated the conference room resources from 2003 to 2010. This is working fine for the vast majority of people. There are a few users however, since the migration, when they try and book a room get the error message, "Microsoft Exchange is not available. Either there are network problems or the Exchange server is down for maintence. Cannot book a resource for this meeting." These users can send and receive email fine, and can book appointments if they do not book a resource. People having the problem are using Outlook versions from 2003 to 2010. If we switch Outlook to run in non-cached mode, the error changes to, "The attempt to log on to Microsoft Exchange has failed."
We logged one user having the problem onto a terminal server, setup the outlook profile and were then able to book a resource. So we removed the user profile (windows profile) completely from her computer and recreated everything, but then had the problem again. All these users are at one remote site, but their mailboxes are hosted on at least 3 different Exchange servers there or here in the main office. We are currently setting up another PC for one of the users to see if that has any effect. So far this is affecting only 7 out of 2500 users. Anybody got any ideas? Thanks.