The present invention relates to systems and methods that predict behaviors of alerting and filtering systems based on simulation from messaging logs. By logging contextual information, such as the presence, activity, and availability of users, as well as incoming messages and their properties, forecasting services can be created that serve to provide users with an interactive "what if" capability, informing them what they might expect in terms of future behaviors of an automated message alerting and/or filtering system, based on recent messaging histories. A log of the history of incoming messages and contextual data is examined by modeling and simulation tools. The tools reveal the influence of alternate settings on the system's behavior, in response to an expected stream of incoming messages, providing users with insights about how control settings affect alerting, filtering, or routing behaviors.