After the Exchange Migration to 2010, we have found most Droids do not reconnect properly. Primarily, the HTC Thunderbolt requires you to remove the account completely and add it fresh. Some other Droids all have the same issue as you are not allowed to edit the Exchange server.
To Remove the account:
Go to Settings
Select Accounts & Sync
Select their Exchange Account
Click Remove Account at the bottom
To Recreate the account: (while still in the Accounts menu)
Click Add Account
Select Exchange ActiveSync
Click Manual Setup (left of the 2 options at the bottom)
Enter their email address and password
Server = legacy.sandiego.edu
Domain = ad
Then click next, next and Finish Setup.