Abstract: A user who received a broadcast message broadcasts a response answering the broadcast message. Sender Y of the broadcast message sends to an electronic mail system through the broadcast message together with identification information on addressees of the broadcast message, and then issues a request to broadcast the message. The electronic mail system sends the message together with the identification information on the addressees of the message to each terminal of users A, B and C as specified by sender Y. On receiving the message, user A generates a response answering the received message, and sends it to the electronic mail system. User A also sends to the electronic mail system the identifiers of users B and C as identification information on addressees of the response according to the received identification information on the addressees of the broadcast message, and then requests the system to broadcast the response. Then, the electronic mail system sends the response to users B and C and sender Y.