A printing apparatus or the like which can print by a simple hardware construction while security is assured and the operability is maintained is provided. A printer receives a print job which is sent from a host computer, holds it into a memory unit, generates an E-mail with a key code corresponding to the print job including the key code of each print job, and sends it to a cell phone designated upon job reception via a mail server through an LAN. In the cell phone which received the E-mail, when the user wants to print, contents of the E-mail are not changed but reply mail corresponding thereto is returned to the printer. In the printer which received the reply mail, if the key code included in the E-mail with the key code coincides with a key code included in the reply mail, the printing of the corresponding print job is started.