COMMUNICATION METHOD, COMMUNICATION SYSTEM, RELAY SYSTEM, COMMUNICATION PROGRAM, PROGRAM FOR COMMUNICATION SYSTEM, MAIL DISTRIBUTION SYSTEM, MAIL DISTRIBUTION METHOD, AND MAIL DISTRIBUTION PROGRAM

摘要

A recipient identifier R and a communication condition information C stored in a recipient-identifier storing unit (11) are encrypted by an identifier-for-disclosure creating unit (12) of a recipient terminal (1) to create an identifier-for-disclosure T. An identifier-for-disclosure notifying unit (13) notifies a sender terminal (2) of the identifier-for-disclosure T. When a communication request using the identifier-for-disclosure T is sent from the recipient terminal (1), a restoring unit (32) of a relay system (3) extracts the communication condition information C from the identifier-for-disclosure T. Only when communication conditions included in the communication condition information are satisfied, communication between the recipient terminal (1) and the sender terminal (2) is established.