Last weekend I moved all user mailboxes from Exchange 2003 to Exchange 2007. I'm trying to create a new mailbox for the first time for an existing user and am receiving Error: ExchangeGuid is mandatory on UserMailbox.
The Exch 2003 Server is still up and running and mail is still routing through it.
We have also introduced 2 new Domain Controllers running Server 2008 R2 this week.
I don't see any thing in the Logs when this happens.
I did try this: http://support.microsoft.com/?id=903291
, but it didn't help.
Thanks in advance.