1. A method of detecting infectious messages, the method comprising: performing a first individual characteristic analysis of a message, wherein the first individual characteristic analysis includes comparing the individual characteristics of the message to individual characteristics of a previously received message; generating a first probability of infection based on the first individual characteristic analysis; generating a second probability of infection based on a second analysis of the message, the second analysis including a traffic analysis for identifying a spike in a number of previously received messages similar to the message, the previously received messages having been classified as suspicious and stored in memory; determining an overall probability of infection based on the first probability and the second probability; and classifying the message as infectious based on the overall probability meeting a threshold, wherein the message is classified as suspicious based on failure of the overall probability to meet the threshold.