A system for transmitting messages comprises stations (S) having an operating system (4), a “network” stage (3) for processing and generating messages in a first format, a communication card (1) for exchanging messages in a second format with a network, a “driver” stage (2) for putting the messages received from the card (1) or the network stage (3) in the first format or second format and transmitting them to the network stage (3) or to said card (1). The stations further comprise a management stage (5) coupled to the operating system (4) and adapted to intercept messages in the first format which are to be exchanged by the network stage and the driver stage so as to analyse the information which they contain and decide to continue their transmission, subject to any required processing, and/or adapted to generate messages in the second format, intended for the stations of the network, when a chosen condition is met.