This paper explores the process of adoption, use and effects of an ICT application (electronic mail) in an organization. This process is considered to be a learning process, in which users, over time, learn to use email to a greater extent, for a broader range of tasks, and more effectively. The results of a longitudinal case study are described. In four time periods (1993, 1995, 1997 and 2000), random samples of users were surveyed with regard to their use of email and its effects. This produced a unique dataset. The longitudinal character of this case study provided an excellent opportunity to follow the learning process through time, and analyse the influence of different variables on the course of this process. MANOVAs show empirical support for the 'learning process', manifested in changes in extent, ways and effectiveness of email use. The analysis indicates that technological innnovation could be an important influence on the course of this learning process.