Abstract: The invention concerns a method enabling users (4a, 4b) of mobile telephones (5, 6) to exchange messages anonymously using simple instructions. The method comprises steps which consist in: storing in a database (2) of a router-server (1) alias names representing the users (4a, 4b) and telephone addresses of the mobile telephones (5, 6) of the users (4a, 4b); sending to an addressee user (4b) a message prepared by a sender user (4a); replying to the sender user (4a) by sending him a message prepared by the addressee user (4b). The addressee user (4b) receives the message sent by the sender user (4a) without the latter revealing his identity and/or knowing the identity of the addressee user, nor using textual instructions to send the message.