Discussion lists have an important part to play in teachers' professional communication. An increasing number of subscribers and the apparent democracy of this medium point to extensive participation in the future, in the service of individuals and their discipline. Yet how can these asynchronous interactions between individuals serve the collective perception of a complex profession, take on the responsibility of accompanying reforms, contribute to teachers' training? and favour the creation of information exchanges? To examine their functioning as regards users' expectations of the system and their needs, two discussion lists of post-secondary school teachers are analysed: the IGC (economics and management), with 2,752 messages corresponding to all interactions since the creation of the list, over three years; and the CDIDOC (research assistants), with 935 messages over one year. The theoretical framework applied to develop the analytical tools and interpret the results is based on the sociology of organizations.