A cloud server is provided. The cloud server includes a transceiver configured to receive, from an electronic device, a fax transmission request and at least one processor configured to control the transceiver to determine a communication network among a plurality of communication networks for communication with an opponent image forming apparatus corresponding to the fax transmission request, when the opponent image forming apparatus is a pre-registered apparatus and transmit fax data corresponding to the fax transmission request to the opponent image forming apparatus using the determined communication network, when the opponent image forming apparatus is a pre-registered apparatus.