A net database retains a user conversion setting table for designating the destination of electronic mail for each user. Based on the contents of the user conversion setting table of the user, a determination module determines the destination of electronic mail received via a mail server. The determination module uses an appropriate conversion module to convert the data of the electronic mail so as to match the output format of the destination. The determination module provides the converted data to the designated destination. Since the contents of the transmission information are converted into a data format corresponding to the capacity of a receiving-side terminal, appropriate information can be provided to the receiving-side terminal.