Transmission control system, transmission system, and method of transmission control

A method of transmission control executed by a transmission control system capable of transmitting data received from a first transmission terminal to a second transmission terminal, the method comprising:

• receiving identification information to identify the second transmission terminal or a user of the second transmission terminal, the data, and first type information that represents a type of the data, from the first transmission terminal;
• accessing a management unit configured to have identification information to identify a predetermined transmission terminal or a user of the transmission terminal, associated with second type information that represents a type of data processible by the predetermined transmission terminal, to be managed, wherein the accessing searches in the management unit, based on the identification information received by the receiving, to read out the second type information corresponding to the received identification information;
• determining whether the first type information received by the receiving is included in the second type information read out by the accessing;
• and
• controlling the data received by the receiving, not to be transmitted to the second transmission terminal, in a case where the determining has determined that the received first type information is not included in the second type information.