Maybe I acceded to quickly? I am trying to understand how to use another delivery channel to support SyncReply. I see CPAid in the MessageHeader so the receiving end knows which CPA to use. I guess the DeliveryChannel is chosen based upon which transport is involved. What if there are two DeliveryChannels with the same transport. One HTTP w/ SyncReply=True and one HTTP w/ SyncReply=False, how does the receiver know which one to use? The CPAid would be the same. Do we need to append the DeliveryChannel ID on the end? <eb:CPAid>CompanyA-003</eb:CPAid> Where CPAid is CompanyA and the DeliveryChannel ID is 003 ? I'm not sure how the sender tells the receiver which DeliveryChannel to use. Please forgive my ignorance but, how does this work? David Fischer Drummond Group.