Message challenge 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.

What is claimed is: 
     
         1 . A method for registering an email sender for the purpose of sending an email message to an email recipient, the method comprising:
 receiving a message from an email sender; and   executing instructions stored in memory, the instructions being executed by a processor to:
 evaluate an identity of the email sender of the received message, wherein the evaluation checks to see if the email sender is on a list of authorized senders that previously sent valid emails to the email recipient, 
 generate a challenge message for the email senders that are not found on the list of authorized senders, 
 transmit the generated challenge message to the email sender, 
 receive a response to the transmitted challenge message from the email sender, 
 process the received message based on the received response, wherein the processing includes generating a notification for the email recipient classifying the received email, and 
 update the list of authorized senders based on the received response. 
   
     
     
         2 . The method of  claim 1 , wherein the generated challenge message includes a plurality of links corresponding to possible answers to the challenge message that the email sender can select. 
     
     
         3 . The method of  claim 2 , wherein the received response is provided via selection of one of the links included in the challenge message. 
     
     
         4 . The method of  claim 1 , wherein the generated challenge message includes a mail identifier that is used to match responses provided by the email sender with the corresponding challenge message. 
     
     
         5 . The method of  claim 1 , wherein the generated notification includes an email message. 
     
     
         6 . The method of  claim 1 , wherein the generated notification further includes information about the email sender. 
     
     
         7 . The method of  claim 1 , wherein the generated notification further includes information about whether the challenge message was answered correctly. 
     
     
         8 . The method of  claim 1 , wherein processing the received email includes classifying the email message as valid and moving the received email to the mail recipient's inbox. 
     
     
         9 . The method of  claim 1 , wherein processing the received email includes classifying the email message as spam. 
     
     
         10 . The method of  claim 9 , wherein the processing further includes deleting the email message identified as spam. 
     
     
         11 . The method of  claim 1 , wherein updating the list of authorized senders includes adding the email sender's address to the list if the email message was classified as valid. 
     
     
         12 . The method of  claim 1 , further comprising:
 generating a list of known spammers, and   maintaining the generated list of known spammers by adding the email sender's address to the list of known spammers if the email message was classified as spam.