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 ?
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 ?
OK, but its the same user, yes?
If so, then remove the Exchange License in Azure.
Then run this:
Set-User <user> -PermanentlyClearPreviousMailboxInfo
Warning: This will remove the mailbox in 365 forever!!
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.
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