An electronic mail (email) processing system set up on the Internet includes terminals that send and receive email messages, cellular telephones that send and receive email messages by radiocommunication through base stations, a mail server that performs the overall management of an email service, a client database, provided within the mail server, for storing user information about registered users who are clients of the email service, and a map database center and a map information provider site, both of which perform a map information providing function. In a specific embodiment, the mail server receives an email message sent from a terminal, adds, to the received email message, telephone number data and position information-associated map link information, which are items of the user information, and forwards the resultant email message to one or more recipient cellular telephones.