This module filters spam using the statistical message processing algorithm. The filter determines the probability of each message containing spam. If the estimated probability exceeds the set limit, the filter blocks the message. The probability is estimated based on the recorded statistics of clean and spam messages. Entensys own design of the Bayesian algorithm allows the filtering module to learn from the Cloud Antispam performance, the administrator's actions (marking a message as "not spam" on the Monitoring page) or users' actions provided IMAP integration is enabled.