To separate a portable mail terminal, which has electronic mail preparation and display functions and a fixed device having transmission and reception functions for the internet from each other, as a PDA(personal digital assistant) exchanging mails with the internet.

The portable mail terminal 1 is provided with a means which prepares an electronic mail to be transmitted to the internet, a means transmits the generated electronic mail and its destination information, and a means which displays a received electronic mail. A fixed device 2 is provided with a means which receives the electronic mail and destination information transmitted from the portable mail terminal 1, a means which converts the received electronic mail and destination information into a format according with a protocol connected to the internet to transmit them, and a means which converts the electronic mail received from the internet to an electronic mail in a form, which can be processed by the portable mail terminal 1, to transmit it.