Patent ID: 7882189

Claim:
A method for e-mail message classification, the method comprising: receiving from a recipient of an e-mail message an indication that the e-mail message is spam; extracting content from the e-mail message before deleting the e-mail message from an inbox of the recipient, wherein the extracted content excludes information that does not distinguish the e-mail message; generating a plurality of signatures based on distinguishing properties identified in the extracted content, and wherein the distinguishing properties exclude: variable portions of contact information related to a sender of the e-mail message, contact information lacking a required character, and contact information including a forbidden character; storing the plurality of signatures as a combination of signatures in a database of signatures; tracking a number of times the combination of signatures appears in the database of signatures; updating the database of signatures based on the tracked number of times the combination of signatures appears; determining whether the tracked number of times the combination of signatures appears exceeds a predetermined threshold; and classifying a subsequently received e-mail message as spam when a set of signatures based on the subsequently received e-mail message matches all of the stored combination of signatures for a previously received spam message and the tracked number of times the combination of signatures appears exceeds the predetermined threshold.