A method and system for controlling message throughput rates of clients connected to a broker device in a publish/subscribe network are disclosed. The broker device determines a maximum allowable message throughput for each client connected to the broker device. If a message-producing rate of a client exceeds the maximum allowable message throughput of the client, the broker device sends a negative acknowledgement (NACK) packet to the client and messages from the client are not accepted at the broker device. The NACK packet includes a maximum allowable message throughput of the client, so the client can adjust its message-producing rate based on the maximum allowable message throughput of the client. The present invention can be applied to a publish/subscribe network as well as a TCP/IP network.