<p>An electronic mail filter comprising: a. a receiver to receive an electronic message and parsing that message as a received image; b. a rejectable message library recorded in or convertible to an image form consistent with the received image; c. an image window specifier to select a part of an image from the rejectable image library; and, d. a comparer to compare sequentially the part of the image from the rejectable image library with the received image to identify as an overlay matches indicative of consistency between the electronic message and one of the library of rejectable messages.</p>
