Error messages when you try to connect Outlook 2007 to Exchange Server: "The action cannot be completed" or "Your Microsoft Exchange Server is unavailable" or "Cannot start Microsoft Office Outlook"ide
http://support.microsoft.com/kb/913843/en-usui
Outlook connection issues with Exchange 2010 mailboxes because of the RPC encryption requirementspa
http://support.microsoft.com/kb/2006508/en-usrest
Troubleshooting Reference for Client Access Serversserver
http://technet.microsoft.com/en-us/library/dd298096(v=exchg.141).aspxrem
2601, 2604, and 2501 MSExchange ADAccess Event IDs when a Microsoft Exchange server restartsget