How to know EAI has triggered the BAPI and acknowledgement is sent?

Hi, we have a RFC enabled BAPI to create Sales Order, the idea is EAI should trigger the BAPI through RFC and Sales Order should get created (and acknowledgement email should be sent to external system/EAI). Now from SAP side, we have configured the RFC connection correctly. EAI people say that they have triggered the BAPI whereas we're unable to find any Sales Order got created through BAPI. Is there any way to know/check whether external system is able to successfully call the BAPI?

Thanks.