Have you looked at the SDK example working with Envelopes in BizTalk 2004 for Flat Files and tried to get it to work with XML Documents? Well, I did and I found it a little trickier than I expected. Key Take Home Points: - De-Batching / Envelope Processing for XML Document must take place on the Receive Port. I have not been able to get it to work on the Send Port, but I am still trying. - Properties...