A sending device locates and stores identifying information for each electronic message sent by the device. A receiving device, upon receipt of an electronic message, locates identifying information for the electronic message and the purported sending device of the message. The receiving device communicates a confirmation request to the purported sending device which contains identifying information for the message. The sending device receives confirmation messages and replies to such messages confirming that the message was sent if identifying information in the confirmation request corresponds to identifying information stored by the sending device and denying that the message was sent if the identifying information in the confirmation request does not correspond to stored data.