When creating an Exchange Server 2013 DAG you may receive an error that the Exchange Trusted Subsystem is not a member of the local Administrators group on specified witness server.
On an Exchange Server 2013 server that is installed with the Mailbox server role, when you attempt to delete the files and folders for a database or database copy that has been removed, you may receive an error.
How to add a database copy to a Database Availability Group member in Exchange Server 2013.
How to move an Exchange Server 2013 database and transaction logs files to a new folder path.
When attempting to remove a database from an Exchange Server 2013 mailbox server you may encounter an error that the database contains one or more mailboxes.