You can define the maximum number of recipient Brokers while defining the multisend best effort cluster connection factory. If you set the maximum limit to n, the client sends the message to exactly n Brokers. If the number of available Brokers is less than n, the message will be sent to all the available Brokers. Message sending will fail only when the message cannot be sent to any Broker in the cluster. For more information about defining the maximum number of receiving Brokers, see "Managing Cluster Connection Factories" in the guide Administering webMethods Broker.