I have a single shared email account on our 2010 Exchange Server (Version: 14.03.0174.001, Windows Server 2008 R2 Standard, Service Pack 1) where the UPN was entered incorrectly during the creation of the mailbox.
Any attempt to migrate this mailbox to Office 365, fails with an error “This domain is not valid for this migration”!
After looking for a way to edit this attribute, and coming up empty, I decided it would be best to ask here.
Any help or advice to help resolve this would be greatly appreciated. :-D