Forum Discussion
Email Deployment Issue
So I have backed myself into a corner with email migration to Office 365. I followed instructions from a vendor who sold us migration software, but it appears I am now in a bit of trouble. The go...
Hi RevLV,
CodeTwo's rep over here.
Regarding the article you followed, please note that before migrating mailboxes you had to disable the synchronization of the msExchMailboxGuid attribute between on-premises AD users and Office 365 users. But even without this attribute Office 365 users are still synchronized with AD and that is why they need to be managed via on-premises Exchange.
If you have already deleted the mailboxes from your on-premises environment (or decommissioned the on-premises server), you need to disable directory synchronization to be able to manage migrated mailboxes through Office 365. Please see this KB article for details: https://www.codetwo.com/kb/managing-mailboxes-in-hybrid-environment/.
All the best,
Adam