This sample shows how to use Delivery Notification on a Send Port to catch and react to adapter send errors inside an Orchestration.
Key Take Home Points: - Delivery Notification is not available on Early Bound Ports. - Must import System.Web.Services to cast the SOAP exception - Set Send Port retries to 0 - Must use a Synchronized scope- Does not work with Send Port Groups
Get more information from the original blog post on this topic: http://www.biztalkgurus.com/blogs/biztalk/archive/2004/08/02/BizTalk-Delivery-Notification-and-NACK-Sample.aspx