Abstract: A system and method are disclosed for registering a email sender for the purpose of sending an email message to an email receiver including receiving a challenge message wherein the challenge message includes a machine answerable question; processing the challenge message to determine that it is a challenge message sent for the purpose of authorizing delivery of the email message; analyzing the question to determine a valid response to the challenge message; and sending the valid response that includes the answer wherein a nontrivial amount of resources are required to send the valid response.

Abstract: A system and method are disclosed for maintaining a whitelist, including: obtaining message data based on an email message sent by a user; extracting recipient information from message data; updating the whitelist using the recipient information.

Abstract: A global response network collects, analyzes, and distributes “cross-vector” threat-related information between security systems to allow for an intelligent, collaborative, and comprehensive real-time response.

Abstract: Handling a message comprises: classifying an incoming message for a recipient, storing the classified message and providing a notification to the recipient, wherein the notification includes summary information about the classified message and an interface that allows the recipient to operate on the classified message.

Abstract: A system and method are disclosed for registering a email sender for the purpose of sending an email message to an email receiver including receiving a challenge message wherein the challenge message includes a machine answerable question; processing the challenge message to determine that it is a challenge message sent for the purpose of authorizing delivery of the email message; analyzing the question to determine a valid response to the challenge message; and sending the valid response that includes the answer wherein a nontrivial amount of resources are required to send the valid response.

Abstract: Systems, methods, and media for classifying messages are disclosed. A plurality of fraud indicators are identified in the message. A signature of the message is generated. The generated signature of the message is compared to a stored signature. The stored signature is based on a statistical analysis of fraud indicators in a second message associated with the stored signature. A determination as to whether the message is fraudulent is made based on the comparison. The message is processed based on the determination that the message is a fraudulent message.

Abstract: Handling a message comprises: classifying an incoming message for a recipient, storing the classified message and providing a notification to the recipient, wherein the notification includes summary information about the classified message and an interface that allows the recipient to operate on the classified message.

Abstract: A system and method are disclosed for improving a statistical message classifier. A message may be tested with a machine classifier, wherein the machine classifier is capable of making a classification on the message. In the event the message is classifiable by the machine classifier, the statistical message classifier is updated according to the reliable classification made by the machine classifier. The message may also be tested with a first classifier. In the event that the message is not classifiable by the first classifier, it is tested with a second classifier, wherein the second classifier is capable of making a second classification. In the event that the message is classifiable by the second classifier, the statistical message classifier is updated according to the second classification.

Abstract: A system and method are disclosed for registering a email sender for the purpose of sending an email message to an email receiver including receiving a challenge message wherein the challenge message includes a machine answerable question; processing the challenge message to determine that it is a challenge message sent for the purpose of authorizing delivery of the email message; analyzing the question to determine a valid response to the challenge message; and sending the valid response that includes the answer wherein a nontrivial amount of resources are required to send the valid response.

Abstract: A system and method are disclosed for improving a statistical message classifier. A message may be tested with a machine classifier, wherein the machine classifier is capable of making a classification on the message. In the event the message is classifiable by the machine classifier, the statistical message classifier is updated according to the reliable classification made by the machine classifier. The message may also be tested with a first classifier. In the event that the message is not classifiable by the first classifier, it is tested with a second classifier, wherein the second classifier is capable of making a second classification. In the event that the message is classifiable by the second classifier, the statistical message classifier is updated according to the second classification.

Abstract: Systems, methods, and media for classifying messages are disclosed. A plurality of fraud indicators are identified in the message. A signature of the message is generated. The generated signature of the message is compared to a stored signature. The stored signature is based on a statistical analysis of fraud indicators in a second message associated with the stored signature. A determination as to whether the message is fraudulent is made based on the comparison. The message is processed based on the determination that the message is a fraudulent message.

Abstract: A system and method are disclosed for registering a email sender for the purpose of sending an email message to an email receiver including receiving a challenge message wherein the challenge message includes a machine answerable question; processing the challenge message to determine that it is a challenge message sent for the purpose of authorizing delivery of the email message; analyzing the question to determine a valid response to the challenge message; and sending the valid response that includes the answer wherein a nontrivial amount of resources are required to send the valid response.

Abstract: Systems, methods, and media for classifying messages are disclosed. A plurality of fraud indicators are identified in the message. A signature of the message is generated. The generated signature of the message is compared to a stored signature. The stored signature is based on a statistical analysis of fraud indicators in a second message associated with the stored signature. A determination as to whether the message is fraudulent is made based on the comparison. The message is processed based on the determination that the message is a fraudulent message.

Abstract: A system and method are disclosed for routing a message through a plurality of test methods. The method includes: receiving a message; applying a first test method to the message; updating a state of the message based on the first test method; and determining a second test method to be applied to the message based on the state.

Abstract: A global response network collects, analyzes, and distributes “cross-vector” threat-related information between security systems to allow for an intelligent, collaborative, and comprehensive real-time response.

Abstract: A global response network collects, analyzes, and distributes “cross-vector” threat-related information between security systems to allow for an intelligent, collaborative, and comprehensive real-time response.

Abstract: Handling a message comprises: classifying an incoming message for a recipient, storing the classified message and providing a notification to the recipient, wherein the notification includes summary information about the classified message and an interface that allows the recipient to operate on the classified message.

Abstract: A system and method are disclosed for registering a email sender for the purpose of sending an email message to an email receiver including receiving a challenge message wherein the challenge message includes a machine answerable question; processing the challenge message to determine that it is a challenge message sent for the purpose of authorizing delivery of the email message; analyzing the question to determine a valid response to the challenge message; and sending the valid response that includes the answer wherein a nontrivial amount of resources are required to send the valid response.

Abstract: A system and method are disclosed for registering a email sender for the purpose of sending an email message to an email receiver including receiving a challenge message wherein the challenge message includes a machine answerable question; processing the challenge message to determine that it is a challenge message sent for the purpose of authorizing delivery of the email message; analyzing the question to determine a valid response to the challenge message; and sending the valid response that includes the answer wherein a nontrivial amount of resources are required to send the valid response.

Abstract: A system and method are disclosed for maintaining a whitelist, including: obtaining message data based on an email message sent by a user; extracting recipient information from message data; updating the whitelist using the recipient information.