According to the present invention, a data transmission device that can transmit data to a destination contained in pre-stored destination information, the data transmission device comprises a determining section that, when the device is instructed to transmit data, determines whether or not destination information contained in the transmission instruction was updated after the last data transmission carried out with reference to the destination information; and a notifying section that, if the determining section determines that the destination information was updated after the last data transmission to the destination, notifies a user having given the transmission instruction that the destination information has been updated.