When using the webMethods Broker as a JMS provider, Integration Server can send and receive JMS messages in accordance with a cluster policy. The cluster policy, which is applied to the cluster connection factory used by a JMS connection alias, determines the Broker to which the message is sent. Integration Server automatically handles sending and receiving JMS messages using the cluster connection factory. However, the multisend guaranteed and multisend best effort cluster policies have specific requirements for the JMS client sending the message. The following sections provide more information about how Integration Server acts as the JMS client for these policies and explain how to override a cluster policy when sending a JMS message.