EXCHANGE13/16 recovering a lost or corrupted migration mailbox

After the Exchange2013 release, the migration of mailboxes depends on the role of the system "Migrating mailboxes". If the role is corrupted or missing, it is bound to affect the migration of the mailbox, so we need to have a way to fix the role.

What is a migration mailbox
When introducing or deploying Exchange2013 or Exchange2016 in the Exchange organization, we find that there is one more user in the ad's Users container. migration.8f3e7716-2011-43e4-96b1-aba62d229136. It resembles a discovery search mailbox, an arbitration mailbox, and belongs to a system mailbox, not a user mailbox. It is responsible for mailbox migrations.
You can run Get-mailbox–arbitration to view the mailbox.
Impact of two migration mailbox loss
After the mailbox is lost, you will not be able to perform a mailbox migration in the Exchange Admin Center, as shown in the error.

Three how to recover a migration mailbox
To resolve this issue, follow these steps:

1. Start the Active Directory Users and Computers snap-in
2. Click Users, and then verify that the following accounts are present:

Note: If you have this account in the Users container, go to step 4.

3. Run the following cmdlet:
Setup /preparead /IAcceptExchangeServerLicenseTerms

4. Run the following cmdlet: Enable mailbox-quorum-identify "migration.8f3e7716-2011-43e4-96b1-aba62d229136"
Set-Mailbox "Migration.8f3e7716-2011-43e4-96b1-aba62d229136" -Arbitration –Management:$true

EXCHANGE13/16 recovering a lost or corrupted migration mailbox