Patent ID: 8676907

Claim:
A relay apparatus comprising: a storing section configured to store an electronic mail message, which has a MIME format; a determining section that searches a mail body of the electronic mail message stored in the storing section for a body text part and determines whether the searched body text part contains a predetermined character string; and a message hiding processing section that, when the determining section determines that the body text part includes the predetermined character string: encodes the body text part according to a predetermined encoding process to generate hiding data that hides the message contained in the body text part; generates an electronic mail message containing replacement text data that includes an address of the relay apparatus in the mail body and the hiding data that is displayed in a part different from the replacement text data; and transmits the generated electronic mail message to a recipient destination; a message release processing section that: receives the transmitted hiding data from the recipient destination; decodes the received hiding data to restore the body text part; and transmits the restored body text part to the recipient destination.