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If we do not provide an endpoint, it will try to send the message using the wsa:to address of the message. Also, if we use the Send mediator in the out path of the ESB without specifying an endpoint, it will send the message as a reply. If we do provide an endpoint, it will send the message according to the information in the endpoint. The endpoint type can be either a Leaf endpoint (i.e. Address, WSDL, Default or Http) or a Group endpoint (Failover, Loadbalance or Recipient List).
The Send Mediator copies any message context properties from the current message context to the reply message received on the execution of the send operation so that the response can be correlated back to the request. Messages may be correlated by WS-A Message-ID, or even simple custom text labels.
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