In sending an e-mail to the mobile phone, the e-mail is first sent to the server apparatus. After the server apparatus identifies the sender, it sends a mail presence notice (MPN) to the mobile phone. When receiving the MPN, the mobile phone memorizes a mail ID included in the MPN in association with user identification of a SIM card. Then, the mobile phone sends a request for header data to the server apparatus based on the mail ID. When receiving the header data completely sent from the server apparatus upon the request, the mobile phone deletes the mail ID which it has memorized in association with the user identification data.