Unable to delete database copy or uninstall mail server

Suppose you are deleting the last copy of the mailbox database or uninstalling the Exchange server and running the following error message

As suggested by the error message, I verified the existence of various possible mailboxes that can be created, namely, regular user mailboxes, arbitration mailboxes, public folder mailboxes, and archive mailboxes.

Check that the regular mailbox does not show anything:

Check that the archive mailbox does not show anything:

Check that the public folder mailbox shows nothing:

Finally, the results of checking the arbitration mailbox are as follows:

However, deleting the mailbox database will still fail due to the same error. What should I do?

# 1 if you are using Exchange 2013, you can use Remove-MailboxDatabase because it indicates the DN of a user who still has a mailbox on the database, but only if the-Verbose parameter is specified

Another possibility is that the database you are trying to delete is an archived mailbox that is kept in a different mailbox database.

The following command helps you list mailboxes that use a specific database as an archive database:

Get-Mailbox | where {$_ .ArchiveDatabase-eq ""}

# case 1

So, I just moved the archive mailbox to another database:

After the move is complete, the database can now be deleted