Receiver HTTP Adaper Response Message problem

We are using HTTP adapter as the receiver for one of our vendor to post XML PO's to vendor's URL.

We are using Transport Protocol-HTTP 1.0

Message Protocol-XI Payload in HTTP Body

Adapter Engine-Integration Engine.

When PO is posted good on vendor's site we get "200" as the reponse message and when PO is failed in the vendor system due to mapping problems still we get "200" response message, Vendor's are sending "400" message for the failure to update their system but our server is not waiting to get "400" response messages. It picks the message of "200" when PO is posted on vendor's URL it is not waiting to get the next message.

Does anyone can help me to resolve this problem.

Thanks in advance!

Mrudula Patel