Abstract: A phishing filter employs a plurality of heuristics or rules (in one embodiment, 12 rules) to detect and filter phishing attempts solicited by electronic mail. Generally, the rules fall within the following categories: (1) identification and analysis of the login URL (i.e., the “actual” URL) in the email, (2) analysis of the email headers, (3) analysis across URLs and images in the email other than the login URL, and (4) determining if the URL is accessible. The phishing filter does not need to be trained, does not rely on black or white lists and does not perform keyword analysis. The filter may be implemented as an alternative or supplemental to prior art spam detection filters.