A communication management system, comprising: a first candidate information manager (57, 5003) that stores registered first candidate information of each one of a plurality of communication terminals, the registered first candidate information associating, for each one of the plurality of communication terminals, one or more candidate counterpart communication terminals each selectable by the communication terminal to have communication, with the communication terminal; a second candidate information manager (60, 5101) that stores second candidate information of a first communication terminal of the plurality of communication terminals, the second candidate information associating a group of one or more member communication terminals, with the first communication terminal; a receiver that receives a request for sending the second candidate information of the first communication terminal, to a second communication terminal of the plurality of communication terminals; a determiner that determines whether any one of the member communication terminals indicated by the second candidate information of the first communication terminal is registered in the first candidate information manager (57, 5003) as a candidate counterpart terminal associated with the second communication terminal, using the registered first candidate information of the second communication terminal, to identify any unregistered member communication terminal; and a transmitter that sends modified second candidate information of the first communication terminal from which information regarding any unregistered member communication terminal(s) is excluded, to the second communication terminal. a first candidate information manager (57, 5003) that stores registered first candidate information of each one of a plurality of communication terminals, the registered first candidate information associating, for each one of the plurality of communication terminals, one or more candidate counterpart communication terminals each selectable by the communication terminal to have communication, with the communication terminal; a second candidate information manager (60, 5101) that stores second candidate information of a first communication terminal of the plurality of communication terminals, the second candidate information associating a group of one or more member communication terminals, with the first communication terminal; a receiver that receives a request for sending the second candidate information of the first communication terminal, to a second communication terminal of the plurality of communication terminals; a determiner that determines whether any one of the member communication terminals indicated by the second candidate information of the first communication terminal is registered in the first candidate information manager (57, 5003) as a candidate counterpart terminal associated with the second communication terminal, using the registered first candidate information of the second communication terminal, to identify any unregistered member communication terminal; and a transmitter that sends modified second candidate information of the first communication terminal from which information regarding any unregistered member communication terminal(s) is excluded, to the second communication terminal.