It is made possible to accurately perform connection determination of whether the line connection satisfies a predetermined connection permission condition in a communication service for transmitting data in a store-and-forward system from a network, in which a calling terminal device is located, to a network, in which a receiving terminal device is located, through one or more communication relay apparatuses of another network and a provider. For this end, in a procedure of transmitting the data in the store-and-forward system from a network (source network) N11, in which a calling terminal device MS1 is located, to a network (destination network) N13, in which a receiving terminal device MS2 is located, through one or more communication relay apparatuses PF11 and PF12 of another network N12 and providers P11 and P12, address information in the source network N11 is maintained without being overwritten, so that the connection determination in the destination network N13 is accurately performed.