RFC 1893 (rfc1893) - Page 2 of 15


Enhanced Mail System Status Codes



Alternative Format: Original Text Document



RFC 1893                Mail System Status Codes            January 1996


   space for delivery notification reporting will reduce the available
   codes for new ESMTP extensions.

   The following proposal is based on the SMTP theory of reply codes.
   It adopts the success, permanent error, and transient error semantics
   of the first value, with a further description and classification in
   the second.  This proposal re-distributes the classifications to
   better distribute the error conditions, such as separating mailbox
   from host errors.

2.   Status Codes

   This document defines a new set of status codes to report mail system
   conditions.  These status codes are intended to be used for media and
   language independent status reporting.  They are not intended for
   system specific diagnostics.

   The syntax of the new status codes is defined as:

          status-code = class "." subject "." detail
          class = "2"/"4"/"5"
          subject = 1*3digit
          detail = 1*3digit

   White-space characters and comments are NOT allowed within a status-
   code.  Each numeric sub-code within the status-code MUST be expressed
   without leading zero digits.

   Status codes consist of three numerical fields separated by ".". The
   first sub-code indicates whether the delivery attempt was successful.
   The second sub-code indicates the probable source of any delivery
   anomalies, and the third sub-code indicates a precise error
   condition.

   The codes space defined is intended to be extensible only by
   standards track documents.  Mail system specific status codes should
   be mapped as close as possible to the standard status codes.  Servers
   should send only defined, registered status codes.  System specific
   errors and diagnostics should be carried by means other than status
   codes.

   New subject and detail codes will be added over time.  Because the
   number space is large, it is not intended that published status codes
   will ever be redefined or eliminated.  Clients should preserve the
   extensibility of the code space by reporting the general error
   described in the subject sub-code when the specific detail is
   unrecognized.




Vaudreuil                   Standards Track