RFC 1894 (rfc1894) - Page 3 of 39

An Extensible Message Format for Delivery Status Notifications

RFC 1894             Delivery Status Notifications          January 1996


    sender wants to report the problem to the remote MTA administrator.

1.2 Requirements

    These purposes place the following constraints on the notification
    protocol:

(a) It must be readable by humans as well as being machine-parsable.

(b) It must provide enough information to allow message senders (or the
    user agents) to unambiguously associate a DSN with the message that
    was sent and the original recipient address for which the DSN is
    issued (if such information is available), even if the message was
    forwarded to another recipient address.

(c) It must be able to preserve the reason for the success or failure of
    a delivery attempt in a remote messaging system, using the
    "language" (mailbox addresses and status codes) of that remote
    system.

(d) It must also be able to describe the reason for the success or
    failure of a delivery attempt, independent of any particular human
    language or of the "language" of any particular mail system.

(e) It must preserve enough information to allow the maintainer of a
    remote MTA to understand (and if possible, reproduce) the conditions
    that caused a delivery failure at that MTA.

(f) For any notifications issued by foreign mail systems, which are
    translated by a mail gateway to the DSN format, the DSN must
    preserve the "type" of the foreign addresses and error codes, so
    that these may be correctly interpreted by gateways.

   A DSN contains a set of per-message fields which identify the message
   and the transaction during which the message was submitted, along
   with other fields that apply to all delivery attempts described by
   the DSN.  The DSN also includes a set of per-recipient fields to
   convey the result of the attempt to deliver the message to each of
   one or more recipients.

1.3 Terminology

   A message may be transmitted through several message transfer agents
   (MTAs) on its way to a recipient.  For a variety of reasons,
   recipient addresses may be rewritten during this process, so each MTA
   may potentially see a different recipient address.  Depending on the
   purpose for which a DSN is used, different formats of a particular
   recipient address will be needed.



Moore & Vaudreuil           Standards Track