A net database retains, for each user, information about a portable terminal and user information including designation of a destination of electronic mail. A determination module determines whether the contents of electronic mail received by a mail server are displayable at the portable terminal of a destination user. If it is determined that the contents are displayable, the electronic mail is sent to the portable terminal of the destination user. If it is determined that the contents are not displayable, the determination module determines the destination of the electronic mail in accordance with the user information. A conversion module converts the electronic mail data into a form outputtable at the destination. The converted data is provided to the destination apparatus, and a notification representing this is notified to the portable terminal.