In the case of the MMS, GateGuard communications ports are defined according to the GateGuard's security level. Besides link encryption between the MMS and GateGuard, the STU- III provides user identification. GateGuard terminals must also complete the MMS log-in process, at the GateGuard's security level, using a user ID and password. The MMS also provides message accountability in addition to the operating system's security audit trail. UNIX electronic mail is used in the MMS to store messages in mailboxes.
Users dial-in to send or receive messages whenever they want.
The user controls message delivery according to the organization's priorities. Organizations that do not operate 24 hours a day can enjoy the convenience of longer-term, secure message storage until normal duty hours. The MMS also supports the advanced notification process. Messages that require advanced notification are identified as such in the user mailbox. A user logs-on to the MMS using a defined variation of the RI to receive these messages.