Patent ID: 7433924

Claim:
A method of intercepting unwanted electronic bulk mail messages comprising: examining a header portion of an electronic message destined to an intended recipient to find a bulk class indicator; responsive to finding said bulk class indicator, further examining said header portion to find an approved sender identifier value; responsive to finding both a bulk class message indicator and an approved sender identifier value, forwarding said message to said intended recipient, including said header portion with said bulk class indicator; responsive to finding a bulk class indicator but not finding an approved sender identifier, intercepting the message by blocking forwarding of the message to said intended recipient; responsive to finding no indication of said bulk class indicator, analyzing said message for bulk message characteristics comprising a step selected from the group of detecting a number of recipients contained in the message recipient list exceeding a pre-determined limit, detecting previously determined objectionable strings or words in the message, detecting instructions in the message regarding how to unsubscribe, detecting text within the message which is similar to message content contained in other messages addressed to recipients other than said intended recipient, and detecting a plurality of messages sent within a pre-determined period of time from a same sender; and responsive to determination that the message has bulk message characteristics, intercepting the message.