Microsoft has simplified the process of removing a mailbox from quarantine starting with Exchange 2013. (Before it was a more complicated process, involving registry edits).
Keep in mind that Exchange quarantines mailboxes for a reason. It tries to correct a problem automatically, but if it fails, it will quarantine the mailbox again, so the root cause of the problem needs to be identified.
First, you need to find which mailbox was quarantined. Open Exchange management shell and run the follow codelet:
To setup Remote Desktop Protocol (RDP) you need to enable the Port 3389 which is the default port number. Follow the path listed below to enable the port for RDP: