Abstract: An improved method is provided for identifying unsolicited bulk email messages. The method includes: monitoring electronic messages being sent to a plurality of recipients; identifying a subset of the electronic messages advertising a particular domain name; assessing reputation of the particular domain name; determining how many recipients received an electronic message from the subset of electronic messages; and deeming the subset of electronic messages to be unsolicited bulk messages when the particular domain name is not reputable and the number of recipients receiving an electronic message from the subset of electronic messages exceeds a threshold.