14. The method of claim 11 , further comprising associating a weight with each attribute in the first attribute set and with each attribute in the second attribute set, wherein each weight is indicative of the likelihood that an electronic document that contains the attribute is spam.
14. The method of claim 11 , further comprising associating a weight with each attribute in the first attribute set and with each attribute in the second attribute set, wherein each weight is indicative of the likelihood that an electronic document that contains the attribute is spam. 15. The method of claim 14 , further comprising modifying the classification of the electronic document based on the weight of each attribute contained in the electronic document.