The invention provides a method and system capable of dynamically filtering incoming messages, with the effect of classifying those messages into one of at least three categories: good messages, bulk periodicals, and spam. An identification engine classifies messages based on a measured intent of each message. The system includes a dynamic whitelist and blacklist into which sending addresses are collected when the number of messages from those addresses indicates that the sender is likely good or likely a spammer. Neural networks are trained with a set of regular expressions to respond to changes in the typical e-mail received by the user.