Tenant to Tenant Migration

Copper Contributor

Hi, Until now when we have migrated mailboxes from one 365 tenant to another we have used the iMap migration option in the Exchange Admin Centre, created a csv of accounts and it worked fine for migrating mail over and we then used the Mover app for OneDrive files.


Since the deprecation of basic authentication the above method no longer works. I have asked Microsoft for an alternative but they said they don't support this and we have to work with an associated partner with 3rd party tools to perform such tasks moving forward and there isn't anything built in we can use (which I found very odd)


In the New Exchange Admin Centre > Migration there is now a migration type called Cross tenant migration, is this what we should be using now to migrate mailboxes? has anyone had experience with it as to what the end result is? and can it be used without 3rd party tools?



3 Replies


Yes, this is newly introduced this year for cross-tenant migration:


Cross-tenant mailbox migration - Microsoft 365 Enterprise | Microsoft Learn

Hi do you know if it brings everything across with the mailbox (contacts, calendars etc) and onedrive files? thanks

Yes, it migrates mailboxes data including contacts, calendars, notes, etc. For OneDrive, you need to follow cross-tenant OneDrive migration process. Also remember, these procedures now require cross-tenant user data migration license.

Read More: Office 365 Tenant to Tenant Migration