An electronic apparatus connected to a server providing real-time messaging through a messaging channel to communicate therewith is provided. The apparatus includes a client communication unit for communicating with the server and at least one external device, the electronic apparatus and the at least one external device forming a client group, and a client controller for classifying the electronic apparatus and the at least one external device in the client group into a header client connected with the messaging channel to the server and a node client, and for controlling the header client to transmit a message about the node client from the server to the node client when the message from the server is transmitted to the header client through the messaging channel.