Message Handling Service. An electronic mail protocol developed by Action Technologies, Inc.
Message Handing System. (Sistema de Tratamiento de Mensaje (STM).)
(n.) is CCITT's X.400 series of recommendations for electronic mail transfer. MHS defines the system of message user agents, message transfer agents, message stores and access units.
MHS is a system used for receiving, storing and sending messages, with a consistent set of protocols, to external devices.
Message Handling System.