Patent ID: 7543076

Claim:
A method for filtering spam, the method comprising: receiving a message that includes header entries arranged in an ordered sequence that indicates a path by which the message was communicated; parsing the header entries included in the message to categorize each header entry as a header type where the header types are listed in the ordered sequence, wherein a header type is comprised of text of a header entry found before a colon in the header entry, wherein parsing includes listing the header types included in the message in the ordered sequence; determining a quantity of each different header type; creating a numeric representation of the ordered sequence of header types, the numeric representation including a unique integer assigned to each different header type; receiving one or more additional messages, wherein each additional message has one or more header entries; analyzing the header entries of the one or more additional messages with a computer learning algorithm to establish a reference by determining which one or more quantities of header types indicate a likelihood of a spam message, wherein each quantity corresponds to a respective header type, and wherein each respective header type corresponds to a respective header entry; and determining whether the message is likely a spam message based at least in part on the quantity corresponding to a particular header type of the message by comparing the quantity corresponding to the particular header type to the established reference of the computer learning algorithm, and at least in part on a sampling of multiple sequential-overlapping segments of the numeric representation of the ordered sequence.