Mobile communication terminal device, communication program, and communication method

A mobile communication terminal device that allows a third party to acquire position information, computed based on received GPS information, without requiring any operation on the side of the user of the mobile communication terminal device equipped with a GPS receiver. The mobile communication terminal device, which is connected to a network via radio, includes: a unit for receiving position information transmit request mail at a special address provided exclusively to accept a position information transmit request; a unit for receiving GPS information from a GPS satellite in response to the received position information transmit request mail; a unit for acquiring current position information based on the received GPS information; and a unit for transmitting the acquired position information as return mail to a predesignated mail address.