Hybrid. Can't move the mailbox to EXO

Question

Hello. The creator of the tenant has a mailbox in EXO before setting up the hybrid configuration.

It is exactly the same as on the local server.

Therefore, when moving from local server to EXO, I can't do it. What to do ?

Answer 1

OK, but its the same user, yes?

If so, then remove the Exchange License in Azure.
Then run this:
Set-User <user> -PermanentlyClearPreviousMailboxInfo

https://techcommunity.microsoft.com/t5/exchange-team-blog/permanently-clear-previous-mailbox-info/ba-p/607619

Warning: This will remove the mailbox in 365 forever!!

Answer 2

The box is deleted, but now when I send an email from EXO to a local server, to this recipient, I get a bounce back that the recipient is not found.

I found that because of this local account in Office365, the account in Active Directory is not synchronized in AAD.