1. A message distribution apparatus for distribution of a message submitted by a submitting user by means of a terminal connected to a communication network to a previously unknown group of receiving users; said message distribution apparatus including a computer coupled to the communication network and comprising: (a) a database which stores a semantic network data model comprising terms linked to each other by at least one of semantic relations and a social network data model comprising users linked to each other by social relations, wherein said semantic network data model comprises: an imported semantic network data model layer, an edited semantic network data model layer, a semantic network data model layer of co-occurrence relations, and an aggregated semantic data model layer aggregated on the basis of other semantic network layers; (b) a mapping engine that receives the message submitted by said submitting user and maps at least one term being associated with the submitted message to at least one of terms being associated with users of said social network data model and terms of said semantic data model for generating at least one group of potential receiving users for said submitted message prior to delivery of the submitted message; and (c) a distribution engine that delivers the submitted message of said submitting user via said communication network to a group of receiving users automatically filtered from the at least one group of potential receiving users generated by said mapping engine, such that the group of receiving users to which the submitted message is delivered is automatically determined by the mapping engine and distribution engine after submission of the submitted message and prior to delivery of the submitted message.