Message Disposition Notification

A Message Disposition Notification (MDN) is an acknowledgment file created by a receiver of a message.  The MDN  is sent to the sender by the receiver to report any success or failure of the received message.  The sender requests an MDN through the message itself or through other manual interaction.  If an MDN is requested via the originating message, it must have the following headers and conditional values:

• “Disposition-Notification-To”.  The header contains only one distinct address.  Furthermore, the address specified by this headers must be the same as the address specified in the "Return-Path" header.  
• “Return-Path”.  If more than one “Return-Path” header exists, only the first is selected.
• “Message-ID”.  Identifier unique to the MDN message.

  NOTE: Comparison of the “Disposition-Notification-To” and the “Return-Path” header is done using the BNR defined addr-spec portion.  Any phrase or routes are excluded from the comparison.  Furthermore, the comparison is case sensitive for the local-part and case insensitive for the domain part.  For example, the local-part "john.smith" is not the same as "John.Smith", but the domain "anon.global.com" is the same as "Anon.Global.Com".  Please see RFC2298.

  Example:

  Disposition-Notification-To: john.smith@anon.global.com
  Return-Path: <john.smith@anon.global.com>
  Message-ID: 123456789.global.com

  Example 2.

Disposition-Notification-To: some user <john.smith@anon.global.com>
Return-Path: <john.smith@Anon.Global.Com>
Message-ID: 123456789.global.com

When an AS2 or AS3 message requests for an MDN, it must have the following:

• "AS2-To/AS2-From" OR "AS3-To/AS3-From".  The message must contain the headers "AS2-To" and "AS2-From" to indicate that it is an AS2 message, or "AS3-To" and "AS3-From" to indicate that it is an AS3 message.
• “Disposition-Notification-To”.  The value contained in this header is not relevant and is not used.  However, it must be present and it must be syntactically correct.
• “Message-ID”.  Identifier unique to the MDN message.

Example (AS2 message):

AS2-To: jane
AS2-From: John
Disposition-Notification-To: user@somesite.com
Message-ID: 123456789.global.com

 Format of an MDN message

The MDN message is a content type “multipart/report” message and consists of 3 body parts in the following order.

1. A body part of human readable explanation of the MDN.
2. A body part of the reported errors.  This body part is a message of content type “message/disposition-notification”.
3. An optional body part containing the original message or some other text that helps in diagnosing the problem.