She always gets the same error message "Unable to open your default email folders. The microsoft exchange server computer is not available." when she starts outlook from any computer. Outlook web access is working for her, however. She seems to be the only user having this problem. Any ideas how i can track this down? (Exchange server 2003, outlook 2003 and 2007)

Can you try in cache/online mode? I assume when you configure the OLK profile, and check the name, it resolves both for the server and user?Sukh

Looks like a RPC problem. You can try to set the encrypt option within the specific account. also see http://support.microsoft.com/kb/2006508

Turned out to be Event 9646, "mapi sessions exceeds the maximum of 32 objects of type 'session'". Just required a quick registry tweak.

Please refer to: http://support.microsoft.com/kb/842022Fiona Liao TechNet Community Support