Email API v.2 - DSN Object Explained

Delivery status notification is a standard SMTP mechanism to obtain message status report directly from recipients' mail server.
DSN object encapsulates this functionality and provides instruction on how to handle the message events/
The property notify contains a string that indicates what message statuses are to be reported: FAILURE,DELAY,SUCCESS are values that can be combined.
FAILURE indicates undelivered message that will not be retried.
DELAY indicates a message that will be re-transmitted at later time.
SUCCESS indicates a message that is reported to be delivered.
NEVER indicates that the server must not notify us. NEVER can not be combined with any of the above (FAILURE,DELAY,SUCCESS) and it will cause a delivery failure if combined with any of the other values.
Unfortunately this method is not always reliable since some servers may respond positively and still block the message at later stages (mostly caused by antispam servers).

Request fields

dsn Delivery Status Notification Object enabling DSN functionality of Email Plus.

notifyString (enumeration)Comma separated notification statuses. Should be comma separated values of FAILURE, DELAY, SUCCESS or NEVER. NEVER cannot be combined with any of the other values.
orcptString (email)Email address (orcpt) to receive the Notification. Must be a well-formed email address.
envidStringEnvelope identifier (envid). It may be set to custom ID if DSN notification will be processed by an automated system.