AS2 Async mdn issue from Partner side.

Hi PI Experts,

My scenario is IDoc---->PI------> AS2 (Third Party).outbound interface.

sending data from PI to Third party successfully but PI not able to receive the MDN from Partner .

while Partner sending the MDN to PI getting error from partner side : ERROR: HTTP failed permanently: 404

Partner able to send the mdn to PI-Dev system we are receiving the mdn successfully .

Partner not  able to send the MDN to PI-QA system .

Please help me on this issue ,this is very urgent.

Thanks,

Aadi