Abstract: An address determining means determines whether an e-mail address in an e-mail is an extended address or an original e-mail address of an e-mail account. The extended address is an e-mail address generated by adding an extension name to an account name in the original e-mail address. A receipt accepting means determines, based on the extended address, whether to accept receipt of an e-mail of which a destination address is the extended address or not. An e-mail receiving means receives the e-mail to the extended address as an e-mail to the e-mail account of the original e-mail address after the receipt accepting means accepts receipt of the e-mail.