Sender REST service to NW BPM 403 forbidden error

Hi Folks,

I am trying to send a Synchronous Request message from REST service to BPM in PO and I and the content Type is application/json for the REST sender channel. The BPM receiver is configured with the correct messaging system URL. When I try to post a message using a REST client, I get the following error messages. Any suggestion would be appreciated.

"Transmitting the message using connection REST_http://advantco.com/xi/XI/REST failed, due to: com.sap.engine.interfaces.messaging.api.exception.MessagingException: java.io.IOException: HTTP Error response for SOAP request or invalid content-type.; HTTP 403 Forbidden"

Regards

Kalyan.