The Mercury Mail Transport System is a <EM>Mail Server</EM> - a program that sends and receives mail on behalf of a group of users on a machine or local area network. Mail from the outside world is received by Mercury and placed in the addressee's mailbox, where the user can access it at any later point. Messages sent by local users to the outside world are passed to Mercury, which then takes whatever steps are necessary to deliver them, removing the burden from the user's workstation and allowing him to continue with other work