1. A method to classify communications from messaging entities, the method comprising: initiating a plurality of interrogation engines, each interrogation engine implementing a message classification technique; initiating a corresponding plurality of index queues, each index queue associated with one interrogation engine; storing, in each index queue, indexes that index communications in a order in which its corresponding interrogation engine is to process the communications; receiving a communication from a messaging entity, wherein the communication is a legitimate e-mail message or spam or a virus or a communication that violates corporate policy; assigning an index to the communication; performing a load evaluation in response to receiving the communication; determining an additional interrogation engine should be initiated based on the load evaluation, and in response to the determination, creating a new index queue and initiating a new interrogation engine, wherein the new index queue is associated with the new interrogation engine; placing the index assigned to the communication into one or more index queues of the plurality of index queues and the new index queue; for each of the one or more index queues into which the index is assigned, using the corresponding interrogation engine and message classification technique to classify the communication; combining, using one or more data processors, results of the message classification techniques to generate a message profile score for the communication; and wherein the message profile score is used in deciding what action is to be taken with respect to the communication associated with the messaging entity, and the communication is interrogated by a plurality of interrogation engines of different types.