Messaging system for mobile terminals where the system utilizes a message server which exchanges messages, originating from the terminals, through use of an identification code. The message server grants each terminal access to the messages originating from terminals which use identification codes that belong to the same group of identification codes. The identification codes within each group can be identical or non-identical, and, as for the latter, the message server arranges the identification codes into groups. The message server "stores and forwards" messages, and provides real-time message exchange; and keeps track of which message originates from which terminal, which message has been retrieved by which terminal and, on a group by group basis, which terminals are simultaneously connected to the message server.