1. A method for detecting undesired email containing image-based messages, the method comprising the steps of: (i) issuing an appropriate token and token value for each of a pre-selected set of text-related characteristics of an email under consideration; (ii) determining if the email under consideration contains an image and, if it does, issuing an appropriate token and token value for each of a pre-selected set of image-related characteristics of the email under consideration; (iii) performing a statistical analysis of the tokens issued for the email under consideration and determining a probability that the email is undesired; and (iv) employing the determined probability to decide whether the email is undesired.