
Network Working Group                                       D. Bernstein
Request for Comments: NNNN                                            IR
Category: Experimental                                     16 March 1996


       The Hash Convention For Mail System Status Codes (HCMSSC)


Status of this memo

   This memo defines an experimental protocol for the Internet
   community. This memo does not specify an Internet standard of any
   kind. Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.


1. Introduction

   RFC 1893 defines codes for mail delivery failures. For example,
   code 5.1.1 means that the specified mailbox does not exist.

   This document proposes to spray these codes all over the place,
   by adding a code to the end of the text of every error message,
   preceded by a hash mark and surrounded by parentheses.


2. Examples

   Here is a typical HCMSSC SMTP error message:

      421 load average too high, please come back later (#4.3.2)

   Here is part of a typical HCMSSC bounce message:

      <mail-loop@silverton.berkeley.edu>:
      This is looping; it already has my Delivered-To line. (#5.7.1)

   But don't use HCMSSC when you repeat another MTA's error message:

      <foo@heaven.af.mil>:
      127.3.4.5 does not like recipient.
      Remote host said: 550 <foo>... User unknown (#5.1.1)


3. Security considerations

   Don't take drastic action upon seeing "(#"; it might not be HCMSSC.


Author's address

   D. J. Bernstein

   EMail:  djb@pobox.com


Bernstein                                                       [Page 1]

