A supervising server (2) is connected to a communication network. The communication network includes a plurality of clients (3) and facsimile servers (1). The supervising server (2) has recipient information such as facsimile numbers of recipients, and the clients (3) can refer to the recipient information under predetermined constraint. All the information about recipients is administered by the supervising server (2). The facsimile servers and clients communicate with each other via the supervising server.