From: aperson@dom.ainTo: bperson@dom.ainContent-Type: multipart/digest; boundary=XYZ--XYZContent-Type: text/plainThis is a text plain part that is counter to recommended practice inRFC 2046, $5.1.5, but is not illegal--XYZFrom: cperson@dom.ainTo: dperson@dom.ainA submessage--XYZ--