I am trying to convert an arbitrary mime part somewhere in a mime hierarchy into a multipart containing the original part and a new part.

This is so that I can receive a message, decompose (decompress, decode documents, etc) it's parts, review the new content, then remove the new content again before sending the message back out.

Here is something like what I tried:

			

			private void expandPart(MimePart mp)
			

			{
			

			MimeMultipart multipart = new MimeMultipart("X-Expanded");
			

			

			MimeBodyPart exPart = getExpandedPart(mp);
			

			

			multipart.addBodyPart((BodyPart)mp);
			

			multipart.addBodyPart((BodyPart)exPart);
			

			

			mp.setContent(multipart);
			

			}
			

		

I expected this to change my original part into a "multipart/X-expanded" part with two child parts: the original part and the expanded version. What I get is a complete mess (based on inspecting the mp at the end of the function).