Fixing the "ExchangeGuid is mandatory on UserMailbox" issue
During a recent Office 365 migration project I ran into an issue on the on-premises Exchange 2013 platform, when trying to create Mail User objects for the migrated mailboxes. The following error appeared when adding a new Mail User: ExchangeGuid is mandatory on UserMailbox. Database is mandatory on UserMailbox. After first verifying that the Exchange… Read More »