A communication device allows a user to get access from the outside via an external public line to obtain e-mail data stored in a device connected to an internal system via a computer network such as a LAN without causing a reduction in security. More specifically, the communication device is connected to a LAN via a LAN I/F and also connected to the public line via a line I/F. If the communication device receives a remote operation command via the public line, a CPU of the communication device gets access to a post office of an e-mail server so as to get e-mail data in accordance with the remote operation command. The obtained e-mail data is converted to facsimile image data and transmitted by means of facsimile to a specified destination.