Removing Exchange Databases Manually from AD

Scenario:  When you attempt to run Get-MailboxDatabase -includePreExchange2013, you get the following error:

The Exchange server for the database object ‘DB11’ wasn’t found in Active directory Domain Services. The object may be corrupted.

You then discovered the mailbox server that used to host the database no longer exists in your organization and was forcibly removed via ADSIEdit.

Resolution:  Remove the orphaned databases via ADSIEdit:

1. Open ADSIEdit.
2. Navigate to Configuration –> Configuration –>Services –> Microsoft Exchange –> Enterprise Exchange –> Administrative Groups –> Exchange Administrative Groups –> Databases.
3. Locate the database and delete it.