The purposes of MDNs, from the Internet Draft:
(a) Inform human beings of the disposition of messages after
succcessful delivery, in a manner which is largely independent
of human language;
(b) Allow mail user agents to keep track of the disposition of
messages sent, by associating returned MDNs with earlier
message transmissions;
(c) Convey disposition notification requests and disposition
notifications between Internet Mail and "foreign" mail systems
via a gateway;
(d) Allow "foreign" notifications to be tunneled through a MIME-
capable message system and back into the original messaging
system that issued the original notification, or even to a
third messaging system;
(e) Allow language-independent, yet reasonably precise, indications
of the disposition of a message to be delivered.
RFC1894 or draft-ietf-receipt-mdn-08.txt would both be reasonable
starting points to create a notification format that is useful for IPP
and follows the requirements of draft-ietf-ipp-not-00.txt.
-Dan Wing