1. A method to analyze electronic messages, the method comprising: sorting a set of messages based on a set of probabilities, the set of probabilities indicating a likelihood that the set of messages belong to a first classification; assigning a first subset of first consecutive ones of the sorted set of messages to a first bucket; assigning a second subset of second consecutive ones of the sorted set of messages to a second bucket, wherein a first message of the second subset of messages is consecutive to a last message of the first subset of messages with reference to the set of probabilities; determining a mean of probabilities of the first subset of messages assigned to the first bucket; storing the mean in a tangible memory; and storing, for respective ones of the messages assigned to the first bucket, an indication that the respective message is assigned to the first bucket in the tangible memory, wherein storing the mean in a tangible memory further comprises: moving a boundary between the first bucket and the second bucket; recalculating the mean of probabilities of messages assigned to the first bucket in response to moving the boundary; repeatedly (1) moving the boundary and (2) recalculating the mean until deviations of the probabilities within the first bucket with respect to the mean are equal to or less than a threshold; and storing a last recalculated mean as representative of the first bucket.