Hi Tushar,
Please check that you are passing message ID in the URL.
How are you consuming the webservice (Async) from soapUI or SAP or Third Party.
The endpoint should be in below format
If SAP is the consumer of the service you can should need configure the "Logical Port" with below settings
Messaing Tab.
RM Protocol: SAP RM
Message ID Protocol : WS-A Message ID
MessageId is used to detected duplicate messages, if you trigger the service with same MessageId the response from previous sucessful execution will be sent back to the consumer.
Another parameter that can passed in URI is QueueId, two or more messages with same Queue ID are processed in same queue on the provider side.
Thank You
Regards
Goverdhan Totawar