PURPOSE: To flexibly transmit messages by changing the kinds of messages to be transmitted to a terminal at a call incoming destination according to time reading the messages from the terminal at the call incoming destination.

CONSTITUTION: In a private exchange 2, the message to be transmitted to a terminal 1 at the call incoming destination is changed according to the time reading the message from the terminal 1 at the call incoming destination. Namely, when reading the message until time t1, a message M1 is transmitted to a message reader, when reading the message from the time t1 to time t2, a message M2, is transmitted to the message reader and when reading the message from the time t2 to time t3, a message M3 is transmitted to the message reader. Thus, the message is transmitted to the terminal at the call incoming destination exactly corresponding to the time.