85. An apparatus for determining a reputation of a message sender, comprising: a network interface that is coupled to a data network for receiving one or more packet flows therefrom; a processor; one or more stored sequences of instructions which, when executed by the processor, cause the processor to carry out the steps of: obtaining two or more lists from two or more list providers; determining which lists of the two or more lists indicate the message sender; extracting from each list of the two or more lists indicating the message sender an individual score for the message sender, representing an individual probability that the message sender sent an unsolicited message; and computing a reputation score for the message sender from the individual scores for the message sender from each list of the two or more lists indicating the message sender; wherein the step of computing the reputation score comprises determining an aggregate score based on the individual score for each list of the two or more lists by performing at least one of a Chi Squared calculation, a Robinson calculation and a Bayes calculation on the individual scores for the message sender.
85. An apparatus for determining a reputation of a message sender, comprising: a network interface that is coupled to a data network for receiving one or more packet flows therefrom; a processor; one or more stored sequences of instructions which, when executed by the processor, cause the processor to carry out the steps of: obtaining two or more lists from two or more list providers; determining which lists of the two or more lists indicate the message sender; extracting from each list of the two or more lists indicating the message sender an individual score for the message sender, representing an individual probability that the message sender sent an unsolicited message; and computing a reputation score for the message sender from the individual scores for the message sender from each list of the two or more lists indicating the message sender; wherein the step of computing the reputation score comprises determining an aggregate score based on the individual score for each list of the two or more lists by performing at least one of a Chi Squared calculation, a Robinson calculation and a Bayes calculation on the individual scores for the message sender. 93. The apparatus of claim 85 , further comprising one or more stored sequences of instructions which, when executed by the one or more processors, cause the one or more processors to carry out the step of, when a particular list indicates an IP address range, setting a bit corresponding to the particular list in a particular list bit mask data structure corresponding to the IP address range.