Office 365 Migration to another tennant

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Senior Member

We have an aquisition for another company we need to move into our tenant.  They currently have 365 as well

us- tenant 1 with companya.com email addresses

their - tenant 2 companyb.com email addresses 

 

Can we have say 10 users at a time connect to tenant 1 but send/receive as companyb.com.  ie, we set the spf record and fwd their mail in tenant 2 to tenant 1.  Maybe some trickery w/ adding their companyb.com as a non-internet upn, setting spfs and fwd their tenant mailboxes to our tenant.

 

Can't be the 1st person to do this, so looking for advice.

 

1 Reply

Not without using third-party tools. Here's what Microsoft is (planning to) offer, but will probably take some time: 

https://techcommunity.microsoft.com/t5/video-hub/supporting-mergers-acquisitions-and-divestitures-in...