Abstract: Each of a plurality of message terminal units (10, 12, 14, 16) has a keyboard (20) for entry of data, a visual display (22) for display of entered and received data, and a logic system (FIG. 4) for processing received and transmitted messages. Each unit stores in a CPU (52) a dedicated user terminal identification. Each transmitted message is annexed to a destination terminal identification and said user terminal identification (FIG. 5). Only a unit with a stored user identification identical to the destination identification in a transmitted message can receive and display transmitted messages. Upon receipt of a message, a terminal sends an automatic response to the sending terminal, which provides an appropriate indication to the sender. The receiver can send a manual acknowledgement (42) to the sender, which causes the message to be cleared from the sender's display.