Using DSNs over failed MDNs and impact on MDN generation during encryption/decryption

[Hamish Tolmie]

Hi,

Under section 1.2 of http://wiki.directproject.org/w/images/a/a1/Implementation_Guide_for_Delivery_Notification_in_Direct_v1.0.pdf either a DSN or a MDN of type "failed" can be used to notify other STA's of message delivery failures.

The java reference implementation has gone with the DSN option, the impact of this is that the agent when determining the set of notifications to produce for a successfully decrypted/encrypted message checks whether the processed message is a MDN as seen here: https://github.com/DirectProject/nhin-d/blob/master/java/agent/src/main/java/org/nhindirect/stagent/mail/notifications/MDNStandard.java#L224

This check only discovers MDNs and not DSNs due to:

MDN: report-type=disposition-notification

DSN: report-type=delivery-status

(MDNStandard.ReportTypeValueNotification == disposition-notification)

This causes processed MDNs to be generated for DSNs but not other kinds of messages (including failed MDNs if those were implemented instead).

Is this intended behaviour?

Thanks,

Hamish