Abstract: Embodiments are directed towards multi-level entity classification. An object associated with an entity is received. In one embodiment the object comprises and email and the entity comprises the IP address of a sending email server. If the entity has already been classified, as indicated by an entity classification cache, then a corresponding action is taken on the object. However, if the entity has not been classified, the entity is submitted to a fast classifier for classification. A feature collector concurrently fetches available features, including fast features and full features. The fast classifier classifies the entity based on the fast features, storing the result in the entity classification cache. Subsequent objects associated with the entity are processed based on the cached result of the fast classifier. Then, a full classifier classifies the entity based on at least the full features, storing the result in the entity classification cache.

Abstract: Embodiments are directed towards multi-level entity classification. An object associated with an entity is received. In one embodiment the object comprises and email and the entity comprises the IP address of a sending email server. If the entity has already been classified, as indicated by an entity classification cache, then a corresponding action is taken on the object. However, if the entity has not been classified, the entity is submitted to a fast classifier for classification. A feature collector concurrently fetches available features, including fast features and full features. The fast classifier classifies the entity based on the fast features, storing the result in the entity classification cache. Subsequent objects associated with the entity are processed based on the cached result of the fast classifier. Then, a full classifier classifies the entity based on at least the full features, storing the result in the entity classification cache.

Abstract: Embodiments are directed towards multi-level entity classification. An object associated with an entity is received. In one embodiment the object comprises and email and the entity comprises the IP address of a sending email server. If the entity has already been classified, as indicated by an entity classification cache, then a corresponding action is taken on the object. However, if the entity has not been classified, the entity is submitted to a fast classifier for classification. A feature collector concurrently fetches available features, including fast features and full features. The fast classifier classifies the entity based on the fast features, storing the result in the entity classification cache. Subsequent objects associated with the entity are processed based on the cached result of the fast classifier. Then, a full classifier classifies the entity based on at least the full features, storing the result in the entity classification cache.

Abstract: Embodiments are directed towards classifying messages as spam using a two phased approach. The first phase employs a statistical classifier to classify messages based on message content. The second phase targets specific message types to capture dynamic characteristics of the messages and identify spam messages using a token frequency based approach. A client component receives messages and sends them to the statistical classifier, which determines a probability that a message belongs to a particular type of class. The statistical classifier further provides other information about a message, including, a token list, and token thresholds. The message class, token list, and thresholds are provided to the second phase where a number of spam tokens in a given message for a given message class are determined. Based on the threshold, the client component then determines whether the message is spam or non-spam.

Abstract: Embodiments are directed towards classifying messages as spam using a two phased approach. The first phase employs a statistical classifier to classify messages based on message content. The second phase targets specific message types to capture dynamic characteristics of the messages and identify spam messages using a token frequency based approach. A client component receives messages and sends them to the statistical classifier, which determines a probability that a message belongs to a particular type of class. The statistical classifier further provides other information about a message, including, a token list, and token thresholds. The message class, token list, and thresholds are provided to the second phase where a number of spam tokens in a given message for a given message class are determined. Based on the threshold, the client component then determines whether the message is spam or non-spam.