Hit a brick wall here. Quote from OutlookCode.com appears to confirm what I am discovering by trial and error:

"You cannot programmatically copy an attachment directly from one Outlook item to another. You must first save the item as a system file."

Is it really impossible to reproduce via VBA what a simple drag and drop can perform? I want to convert a message stored as an attachment into a message in its own right, without moving from the confines of Outlook.