SMTP Delivery Status Notification and Message Disposition Notification(RFC 1891 and RFC 2298)

The following is an excerpt from section 2.4.3.3 in the RNIF 2.0 
Core Specification:

Email-based message transfer is a store-forward-based message delivery 
mechanism and the SMTP messages need not be sent directly between the source and 
the eventual recipient's SMTP nodes (due to SMTP routing involved). Hence, 
trading partners cannot rely on any synchronous transport level errors 
(analogous to HTTP response/error codes) being 
returned. Therefore, trading partners MUST have a mechanism in place to handle 
undeliverable email messages sent to each other. Delivered messages with content 
problems SHOULD, however, result in the recipient sending separate RosettaNet 
Exception business signals. If desired, trading partners could use the SMTP 
Delivery Status Notification (DSN) mechanism (see RFC 1891) to request that the 
recipient notify the sender of SMTP message delivery status. Partners could also 
use the SMTP Message Disposition Notification (MDN) mechanism as needed. These 
are part of the standard SMTP message delivery mechanism / standard and can be 
used by trading partners as needed and feasible, based on their SMTP set-ups. 
RosettaNet does not provide any explicit specification in this 
respect.

Should the use of DSN and MDN be specifiable as part 
of the SMTP protocol?

-Arvola