Abstract: A method and system for filtering email spam using email noise reduction are described. In one embodiment, the method includes detecting, in an email message, data indicative of noise added to the email message to avoid spam filtering. The method further includes modifying the content of the email message to reduce the noise, and comparing the modified content of the email message with the content of a spam message.

Abstract: Systems and methods for filtering spam messages utilizing a URL filtering module are described. In one embodiment, the method includes detecting, in an incoming message, data indicative of a URL and comparing the URL from the incoming message with URLs characterizing spam. The method further includes determining whether the incoming message is spam based on the comparison of the URL from the incoming message with the URLs characterizing spam.

Abstract: A method and system for filtering email spam using email noise reduction are described. In one embodiment, the method includes detecting, in an email message, data indicative of noise added to the email message to avoid spam filtering. The method further includes modifying the content of the email message to reduce the noise, and comparing the modified content of the email message with the content of a spam message.

Abstract: A server is disclosed for filtering e-mail messages. The server receives requests to retrieve e-mail messages on behalf of a client and then retrieves e-mail messages from a mail server on behalf of the client. The server then filters the e-mail messages based on one or more rules and transfers the filtered e-mail messages to the client. In addition, the server continues to filter the e-mail messages after the client has disconnected from the server. In one embodiment of the invention the e-mail message recipient is sent a notification by the server indicating that messages have been filtered. The recipient is then able to scan the filtered messages and insure that the messages have been filtered correctly. In another embodiment, a third party scans the e-mail messages on behalf of the e-mail user to make this determination. Also disclosed is an e-mail filter comprising an application programming interface and a plurality of dynamically loaded rule modules adapted to interface with the API.

Abstract: A method and system for filtering email spam using email noise reduction are described. In one embodiment, the method includes detecting, in an email message, data indicative of noise added to the email message to avoid spam filtering. The method further includes modifying the content of the email message to reduce the noise, and comparing the modified content of the email message with the content of a spam message.

Abstract: Systems and methods for filtering spam messages utilizing a URL filtering module are described. In one embodiment, the method includes detecting, in an incoming message, data indicative of a URL and comparing the URL from the incoming message with URLs characterizing spam. The method further includes determining whether the incoming message is spam based on the comparison of the URL from the incoming message with the URLs characterizing spam.

Abstract: A method and system for a character-based document comparison are described. In one embodiment, the method includes dividing a first document into tokens. Each token includes a predefined number of sequential characters from the first document. The method further includes calculating hash values for the tokens and creating, for the first document, a signature including a subset of hash values from the calculated hash values and additional information pertaining to the tokens of the first document. The signature of the first document is subsequently compared with a signature of a second document to determine resemblance between the first document and the second document.

Abstract: A method and system for filtering email spam based on similarity measures are described. In one embodiment, the method includes receiving an incoming email message, generating data characterizing the incoming email message based on the content of the incoming email message, and comparing the generated data with a set of data characterizing spam messages. The method further includes determining whether a resemblance between the data characterizing the incoming email message and any data item from the set of data characterizing spam messages exceeds a threshold.

Abstract: A method and system for filtering email spam using email noise reduction are described. In one embodiment, the method includes detecting, in an email message, data indicative of noise added to the email message to avoid spam filtering. The method further includes modifying the content of the email message to reduce the noise, and comparing the modified content of the email message with the content of a spam message.

Abstract: A server is disclosed for filtering e-mail messages. The server receives requests to retrieve e-mail messages on behalf of a client and then retrieves e-mail messages from a mail server on behalf of the client. The server then filters the e-mail messages based on one or more rules and transfers the filtered e-mail messages to the client. In addition, the server continues to filter the e-mail messages after the client has disconnected from the server. In one embodiment of the invention the e-mail message recipient is sent a notification by the server indicating that messages have been filtered. The recipient is then able to scan the filtered messages and insure that the messages have been filtered correctly. In another embodiment, a third party scans the e-mail messages on behalf of the e-mail user to make this determination. Also disclosed is an e-mail filter comprising an application programming interface and a plurality of dynamically loaded rule modules adapted to interface with the API.