From: aperson@dom.ain To: bperson@dom.ain Content-Type: multipart/digest; boundary=XYZ --XYZ Content-Type: text/plain This is a text plain part that is counter to recommended practice in RFC 2046, $5.1.5, but is not illegal --XYZ From: cperson@dom.ain To: dperson@dom.ain A submessage --XYZ--