1. A method, comprising: receiving an electronic message that is addressed to a user; determining, by at least one processor, one or more attributes of the electronic message; determining, by the at least one processor, an intersection between the determined one or more attributes of the electronic message and a first lexicon of attributes that are associated with spam electronic messages; determining, by the at least one processor, whether the intersection exceeds a precision threshold, the precision threshold indicating the reliability of the intersection between the determined one or more attributes of the electronic message and the first lexicon of attributes; and if the intersection exceeds the precision threshold: determining an electronic message signature based on the intersection, and comparing the electronic message signature to each of a plurality of signatures associated with spam electronic messages.