Re: regarding illegally formed address and commands

Jack De Winter <> Wed, 25 December 1996 06:08 UTC

Received: from cnri by id ai06627; 25 Dec 96 1:08 EST
Received: from by CNRI.Reston.VA.US id aa20519; 24 Dec 96 21:06 EST
Received: from localhost ( []) by (8.7.6/8.6.12) with SMTP id UAA25415; Tue, 24 Dec 1996 20:36:25 -0500 (EST)
Received: from ( []) by (8.7.6/8.6.12) with ESMTP id UAA25403 for <>; Tue, 24 Dec 1996 20:36:14 -0500 (EST)
Received: by from localhost (router,SLMailNT V3.0); Tue, 24 Dec 1996 20:29:56 -0500
Received: by from ( daemon,SLMailNT V3.0); Tue, 24 Dec 1996 20:29:56 -0500
Message-Id: <>
Date: Tue, 24 Dec 1996 20:34:38 -0500
Precedence: bulk
From: Jack De Winter <>
Subject: Re: regarding illegally formed address and commands
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
X-Sender: "Jack De Winter" <>
X-Mailer: Windows Eudora Pro Version 3.0 (32)
X-Listprocessor-Version: 8.1 beta -- ListProcessor(tm) by CREN

>RFC821 was amended by RFC1123. Section 2.1  states:
>   2.1  Host Names and Numbers
>      The syntax of a legal Internet host name was specified in RFC-952
>      [DNS:4].  One aspect of host name syntax is hereby changed: the
>      restriction on the first character is relaxed to allow either a
>      letter or a digit.  Host software MUST support this more liberal
>      syntax.
>So is legal (as is, but I believe that and
>are still illegal.  You may wish to read all the *rest* of RFC1122 and 1123,
>and see what *other* RFC's they modified and clarified, and look to see if
>they require any code changes in SLMail...

Actually, I did catch that, but for some reason blanked it out.  But
I guess my question still stands.

So far, Dan Bernstein has given the only answer: accept it and then
decide what to do with it at a later date.  He recommended this for
the MAIL FROM, but not RCPT TO.  I am still trying to figure out
what the best response for an illegally formed RCPT is.  I would want
to make it separate enough that it would stand out.

Jack De Winter - Wildbear Consulting, Inc.
(519) 576-3873

Author of SLMail(95/NT) ( and other great products.