1. A computer-implemented method for associating website browsing behavior with a spam mailing list, comprising: collecting a history of website browsing behavior for each of a plurality of users; identifying at least one spam mailing list that includes an e-mail address for a first user and an email address for a second user of the plurality of users; determining if a level of similarity between a first email message received at the e-mail address for the first user and a second email message received at the e-mail address for the second user exceeds a threshold; upon determining that the level of similarity exceeds the threshold; determining if a common website exists between the history of website browsing behavior for the first user and the history of website browsing behavior for the second user; and upon determining that a common website exists, updating reputation information for the common website, wherein the reputation information indicates a likelihood that e-mail messages sent to e-mail addresses on the at least one spam mailing list originate from the common website.
1. A computer-implemented method for associating website browsing behavior with a spam mailing list, comprising: collecting a history of website browsing behavior for each of a plurality of users; identifying at least one spam mailing list that includes an e-mail address for a first user and an email address for a second user of the plurality of users; determining if a level of similarity between a first email message received at the e-mail address for the first user and a second email message received at the e-mail address for the second user exceeds a threshold; upon determining that the level of similarity exceeds the threshold; determining if a common website exists between the history of website browsing behavior for the first user and the history of website browsing behavior for the second user; and upon determining that a common website exists, updating reputation information for the common website, wherein the reputation information indicates a likelihood that e-mail messages sent to e-mail addresses on the at least one spam mailing list originate from the common website. 10. The method of claim 1 , further comprising copying a browser history for a user and transmitting the copy of the browser history to a back end computing device for processing.