System for eliminating unauthorized electronic mail

Abstract

A system for eliminating unauthorized email sent to a user on a network analyzes the sender address of incoming email and determines whether it is to be rejected by returning a standard “no such user” error code or accepted depending upon executing processing rules and analyzing managed lists of authorized senders. This provides an advantage over existing anti-spam filtering systems by intercepting unauthorized email before it reaches an existing email server or client. The system rejects all email unless authorized by using a standard “no such user” error code, and by redirecting the unauthorized email back to the sender or to a sender evaluation site. An ASL module captures authorized sender addresses from the user's outgoing email and other sources in order to update “authorized senders” lists. The system may employ a WBM procedure that notifies senders of rejected email to go to a separate website and register as valid senders after passing an interaction test that precludes automatic registration by a mechanical program. A destination proxy email address procedure allows subscribers to use temporary proxy addresses for receiving email expected from unknown sources and instantiates senders as authorized upon receiving the expected email to the proxy addresses. The unauthorized-email rejection component can be readily configured as a hardware or software appliance used in tandem with a conventional email server, email gateway, or firewall to an intranet, or as a software extension to an existing firewall system.

1 - 35 . (canceled) 
     
     
         36 . A system, comprising:
 one or more hardware processors and one or more computer memories together providing:   an email proxy pre-processing module that is configured to allow designation of a proxy email address that is associated with a primary email address but distinct from the primary email address to receive email from email addresses not on an authorized senders list, wherein the authorized senders list maintains email addresses authorized to have emails sent to the primary email address received by the primary email address, wherein, upon receiving incoming email addressed to the proxy email address from an email address not on the authorized senders list, the email proxy pre-processing module is further configured to accept the email and to add the email address from which the incoming email was received to the authorized senders list.   
     
     
         37 . The system of  claim 36  further comprising an unauthorized-email rejection component that is configured to be positioned in the flow of incoming email upstream from an email-receiving server, such as to intercept unauthorized email and to prevent unauthorized email from reaching the email-receiving server. 
     
     
         38 . The system of  claim 37 , further comprising a web-based messaging (WBM) component configured to send a message to an email address from which rejected email is received inviting to validate the email address from which rejected email is received as an authorized' sending email address. 
     
     
         39 . The system of  claim 38 , wherein the WBM component is further configured to specify a predetermined time period for the email address from which rejected email is received to be validated as an authorized sending email address. 
     
     
         40 . The system of  claim 38 , wherein the WBM component is further configured to require an interaction procedure to be passed to show that a mechanical program is not seeking to automatically validate the email address from which rejected email is received. 
     
     
         41 . The system of  claim 40 , wherein the interaction procedure includes a display of a graphic image of a word or object, and an input to enter in a text word in response to the graphic image, whereby the system can confirm that the interaction procedure is not being performed by a mechanical program. 
     
     
         42 . The system of  claim 36  further comprising an unauthorized-email rejection component having an authorized senders list (ASL) module configured to maintain email addresses authorized to have email sent to the primary email address received by the primary email address, wherein the unauthorized-email rejection component is configured to operate with an email-receiving server to intercept and reject any email addressed to the primary email address received from an email address not on the authorized senders list, wherein the unauthorized-email rejection component is further configured to, upon the ASL module determining that incoming email is received from an email address that is not on the authorized senders list, reject the incoming email with an industry standard “no such user” error message. 
     
     
         43 . The system of  claim 36  further comprising an unauthorized-email rejection component that is configured to, in response to the email proxy pre-processing module receiving incoming email addressed to the proxy email address from an email address not on the authorized senders list, add to the authorized senders list an entry indicating all email addresses of the same domain as the email address from which the incoming email is received. 
     
     
         44 . The system of  claim 36 , wherein the email proxy pre-processing module includes a control parameter configured to limit usage of the proxy email address,to terminate acceptance of email sent to the proxy email address from email addresses not on the authorized senders list, and to prevent addition to the authorized senders list. 
     
     
         45 . The system of  claim 44 , wherein the control parameter is a maximum number of different email addresses from which email sent to the proxy email address will be accepted. 
     
     
         46 . The system of  claim 44 , wherein the control parameter is a maximum period of time after the most recent email from an email address not on the authorized senders list was accepted that the next email from an email address not on the authorized senders list may be accepted. 
     
     
         47 . A method, comprising:
 designating a proxy address that is associated with a primary address but distinct from the primary address to receive electronic messages from other addresses not on an authorized senders list, wherein the authorized senders list maintains addresses authorized to have electronic messages sent to the primary address received by the primary address,   upon receiving an incoming electronic message addressed to the proxy address from an address not on the authorized senders list,
 accepting the incoming electronic message; and 
 adding the address from which the incoming electronic message was received to the authorized senders list. 
   
     
     
         48 . The method of  claim 47  further comprising, upon receiving an incoming electronic message addressed to the proxy address from an address not on the authorized senders list, adding to the authorized senders list an entry indicating all addresses of the same domain as the address from which the incoming electronic message is received. 
     
     
         49 . The method of  claim 47  further comprising, setting a control parameter for limiting usage of the proxy address and terminating acceptance of electronic messages sent to the proxy address from addresses not on the authorized senders list and preventing addition to the authorized senders list. 
     
     
         50 . The method of  claim 49 , wherein the control parameter is a maximum number of different addresses not on the authorized senders list from which electronic message sent to the proxy address will be accepted. 
     
     
         51 . The method of  claim 49 , wherein the control parameter is a maximum period of time after the most recent electronic message from an address not on the authorized senders list was accepted that the next electronic message from an address not on the authorized senders list may be accepted. 
     
     
         52 . A computer-readable storage device having instructions stored thereon, the instructions comprising:
 instructions to designate a proxy email address that is associated with a primary email address but distinct from the primary email address to receive email from email addresses not on an authorized senders list, wherein the authorized senders list maintains email addresses authorized to have email sent to the primary email address received by the primary email address,   instructions to, upon receiving incoming email addressed to the proxy email address from an email address not on the authorized senders list,
 accept the incoming email; and 
 add the email address from which the incoming email was received to the authorized senders list. 
   
     
     
         53 . The computer-readable storage device of  claim 52  further comprising instructions to establish a control parameter for limiting usage of the proxy email address and terminating acceptance of email sent to the proxy email address from email addresses not on the authorized senders list and preventing addition to the authorized senders list 
     
     
         54 . One or more computer memories collectively storing a proxy email address data structure, the data structure comprising a plurality of entries, each entry comprising:
 information indicating a primary email address;   information indicating a proxy email address associated with the indicated primary email address that is distinct from the indicated primary email address;   information indicating a maximum number of sending email addresses that may be instantiated for the indicated proxy email address, wherein the maximum number of sending email addresses is at least two; and   information indicating the total number of sending email addresses that have been instantiated for the indicated proxy email address,   
       wherein the contents of the data structure may be used to forward a message addressed to the proxy email address indicated by a distinguished entry received from an uninstantiated sending email address to the primary email address indicated by the distinguished entry only if the maximum number of sending email addresses that may be instantiated indicated by the distinguished entry exceeds the total number of instantiated sending email addresses indicated by the distinguished entry. 
     
     
         55 . The computer memories of  claim 54  wherein at least one entry including the distinguished entry further comprises:
 information indicating a relative expiration period length for the entry; and 
 information indicating the most recent date on which a sending email address was instantiated for the indicated proxy email address, 
 
       wherein that the contents of the data structure may be used to forward a message addressed to the proxy email address indicated by a distinguished entry received from a presently-unknown sending email address to the primary email address indicated by the distinguished entry only if both (a) the maximum number of sending email addresses that may be instantiated indicated by the distinguished entry exceeds the total number of instantiated sending email addresses indicated by the distinguished entry, and (b) the current date is earlier than a date obtained by adding the relative expiration period length indicated by the distinguished entry to the most recent date on which a sending email address was instantiated indicated by the distinguished entry.