Pervasive messaging is the part of pervasive computing that enables users to communicate with each other. Many of today's electronic messaging systems have their own distinct merits and peculiarities. Pervasive messaging will have to shield the user from these differences. In this paper, we introduce a taxonomy for electronic messaging systems, providing a uniform way to analyze, compare, and discuss electronic messaging systems. With this taxonomy, we analyze the current practice, demonstrating its shortfalls. To overcome these shortfalls, we introduce a novel messaging model: The Unified Messaging System. This system can, in fact, mimic any electronic messaging system, thus providing powerful unified messaging
