A safe electronic mail system for electronic mail communication, realizing connection between mail servers using a dial-up line not through the Internet. The transmitting party is provided with a transmission mail server, a transmission client for generation electronic mail information, and a transmission agent, which is a client for transmitting via a dial-up line. The receiving party is provided with a reception mail server, a reception client which can be the final destination of electronic mail information, and a reception agent, which is a client for receiving via a dial-up line. The transmission agent transmits electronic mail whose final destination is a designated reception client to the reception agent via the dial-up line as a facsimile image, and the reception agent transfers a received electronic mail to the reception mail server.