Patent ID: 8572186

Claim:
A gateway device arranged between a client terminal and a server, and arranged to relay transmission and reception of e-mails, the gateway device comprising: a receiving device arranged to receive first e-mails stored in the server; a converting device arranged to convert the first e-mails into second e-mails for temporary storage; a transmitting device arranged to transmit the second e-mails to the client terminal; and a management table arranged to manage information about the first e-mails and the second e-mails; wherein when the gateway device receives a request from the client terminal to receive the second e-mails, the gateway device sends a request to the server and receives the first e-mails from the server with the receiving device and establishes a connection with the client terminal, and while the connection is maintained, the first e-mails received from the server are converted into the second e-mails by the converting device and transmitted to the client terminal by the transmitting device; and when the gateway device receives a STAT command from the client terminal, the gateway device transfers the STAT command to the server, receives from the server a message including a total byte count of the first e-mails stored in the server, and returns to the client terminal a message including a total byte count of the second e-mails which are converted from the first e-mails.