When trying to open Outlook 2010, you get this error:
Cannot open your default email folders…
Basically this happens if you’ve upgraded Exchange and moved someone’s mailbox. The result is that their connections in AD still point to the old Exchange server. There are two workarounds and one fix for this. First workaround is to delete your Outlook profile and launch Outlook. Second workaround is to use OWA instead (not ideal). Lastly the fix can be found here.