E-MAIL SYSTEM, CONTROL METHOD FOR E-MAIL SYSTEM, RELAY DEVICE, PROGRAM, AND INFORMATION STORAGE MEDIUM

摘要

To provide an e-mail system for ensuring that a user is able to know content of an e-mail sent addressed to the user even when the e-mail is not delivered to the user. An e-mail sending unit (220) sends an e-mail sent addressed to the alternative mail address of the user to the actual mail address of the user, after setting a predetermined destination as a destination of a notice of failed delivery, if caused, of the e-mail. In a case where the notice of failed delivery of the e-mail sent addressed to the actual mail address of the user is received by the predetermined destination, an undelivered mail data saving unit (230) saves undelivered mail data indicating the undelivered e-mail in an undelivered mail data storage unit (410). An undelivered mail data sending unit (110) sends undelivered mail data indicating an e-mail sent addressed to the actual mail address of the user and failed to be delivered to a terminal device used by the user.