To prevent the user of a mobile communication terminal from receiving unexpected junk e-mails.

The user previously notifies a party from which an e-mail containing an URL in a text can be received about a set password, sets delivery refusal setting to a delivery refusal setting section 22 of a mail server 1, and the set password is stored in a set password storage 23. The mail server 1 retrieves whether or not the URL is contained in the text of an e-mail transmitted to the mail server 1, and if it is contained, the server 1 checks the section 22. If the section 22 is set at a delivery refusal setting, a delivery password retrieval section 12 retrieves a delivery password contained in the e-mail, and a password determination means 13 determines whether or not the delivery password matches a set password. When it is determined that the password matches, the e-mail is sent to the user, and it is determined that the password does not match, the e-mail is deleted.