UPDATE NOV 1, 2022: Cross-tenant mailbox migration is now generally available! See Cross-tenant User Data Migration is Now Generally Available for details.
Historically, wh...
Updated Jan 07, 2025
Version 10.0
Blog Post
Paulkot All the legacy mailboxes remaining in the on-premises tenant are Remote (ExO mailboxes, migrated from OnPrem so the AD-DS schema is already present Onprem). We just acquired an organization and have 150 mailboxes (all ExO, no AADC sync) to move into our tenant. I was able to use the scripts provided in the Cross Tenant resource to create the objects via New-MailUser (while connected to ExO) then set the clould object immuitibleid to match the onprem object. I was able to then get a successful Test-MigrationServerAvailabiltiy result.
I suppose this would work, just wondered if there was a more efficient way.
Assuming the Result says Success and Is Valid = True result from the Test-MigrationServerAvailabiltiy, i should be good to go, right?
Once mailboxes are moved, I should be able to Update DNS, and then shut-down the previous O365 tenant?