System and method for preventing delivery of unsolicited and undesired electronic messages by key generation and comparison

A method comprising:

• receiving a first electronic message that includes a request to confirm that a second electronic message sent to an intended recipient was sent on behalf of an originator identified in the second electronic message, the first electronic message including a first data string purportedly generated by application of an algorithm to a portion of said second electronic message and further including said portion of said second electronic message;
• generating a second data string, different from said first data string, by application of an algorithm to said portion of said second electronic message included in said first electronic message;
• comparing said first data string to said second data string;
• and
• upon determining that said first data string does not match said second data string, responding to said first electronic message, denying said second electronic message was sent on behalf of the originator identified in the second electronic message.

A method comprising:

• receiving a first electronic message that includes a request to confirm that a second electronic message sent to an intended recipient was sent on behalf of an originator identified in the second electronic message, the first electronic message including a first data string generated by application of an algorithm to a portion of said second electronic message and further including said portion of said second electronic message;
• generating a second data string, different from said first data string, by application of an algorithm to said portion of said second electronic message included in said first electronic message;
• comparing said first data string to said second data string;
• and
• upon determining that said first data string matches said second data string, responding to said first electronic message, affirming said second electronic message was sent on behalf of the originator identified in the second electronic message.

A method comprising:

• receiving from a sending device a first electronic message authorized by an originator and directed to an intended recipient, said first electronic message containing an identifier associated with the originator and further containing a first data string generated by application of an algorithm to a portion of said first electronic message;
• sending to a confirmation device a second electronic message that includes a request to confirm that said first electronic message was authorized by the originator associated with the identifier, said second electronic message including said first data string and said portion of said first electronic message;
• receiving from the confirmation device a response to said second electronic message affirming said first electronic message was authorized by the originator associated with the identifier;
• allowing said first electronic message to be further processed according to rules for processing of confirmed electronic messages directed to the intended recipient;
• receiving from the sending device a third electronic message authorized by the originator, said third electronic message containing the identifier and further containing a second data string generated by application of an algorithm to a portion of said third electronic message;
• and
• sending to the confirmation device a fourth electronic message that includes a request to confirm that said third electronic message was authorized by the originator associated with the identifier, said fourth electronic message including said second data string and said portion of said third electronic message.