From: bdb@becker.GTS.ORG (Bruce Becker)
Subject: Re: dxmail on ULTRIX
Organization: G. T. S., Toronto, Ontario
Date: Mon, 23 Nov 1992 01:07:40 GMT

In article <1992Nov16.142027.21114@decuac.dec.com> avolio@dco.DEC.COM (Frederick M. Avolio) writes:
|
|If I have an address
|
|		something!else%host.UUCP@domain
|
|while it is ugly, and I'd rather die than generate such an address, the
|assumption is that "domain" will handle what is on the right hand side and
|if it generated it, it must be able to handle it. 
|
|While all of this is ugly, it is allowed because it is on the
|left of the @ sign.  There is only one way to handle the above address.
|Send it to "domain" for "domain" to handle "something!else%host.UUCP" however
|it wants to. It is not a question of defined or undefined.  I have no
|business looking at what is clearly the localpart of the address.
|
|The case in question was a sendmail.cf that erroneously looked at this address
|and decided it should go to "something".  This is wrong.  The sendmail.cf
|in question actually took the address (again, using the above example) and
|changed it to
|
|	something!else%host.UUCP<@domain>
|
|correctly focusing on "domain" and then decided, no, there is a bang in
|there so then it changed it to the erroneous:
|
|	else%host.UUCP@domain<@something.UUCP>
|
|Based on that, it sent it via the wrong transport to the wrong host.  The
|corrected sendmail.cf that I sent fixed this problem.
|
|The point is that anything to the left of the @ is up to the host to the
|right of the @ to handle.  You -- and the ultrix sendmail.cf shipped with
|the product -- are breaking the rules.  You are peaking.  No peaking allowed.


	Yes, the sendmail.cf in Ultrix is broken,
	in more ways than just this.  So also are
	most that are shipped - a visible example
	of what else may also be wrong if one was
	to look at the source for many things.  A
	way of fixing this problem is needed, but
	there seems to be difficulties deciding a
	proper course, to wit:


	Sadly the interpretations in the uucp and
	the internet worlds differ.  Mailers such
	as smail 2.5 for uucp sites understand no
	special interpretation for "%", so in the
	case above delivery fails for "something"
	to send to local user "else%host.UUCP" (a
	patch exists which translates "%" into an
	"@" and attempts to resolve the result).


	"something!else%host.UUCP@domain" thus is
	routed "domain!something!else%host.UUCP".
	The mailer at "something" hopefully would
	route "host!else", if it's able to.



	In the domain system only the domain name
	is relevant for routing purposes, but the
	situation is not so well defined when the
	target system's mailer is invoked.  There
	seems to be a belief that "%"'s should be
	resolved as soon as they are seen, rather
	than by the mailer of last resort as it's
	usually practiced in the uucp world.


	"something!else%host.UUCP@domain" thus is
	"something!else@host.UUCP" via "domain" -
	this is clearly not at all the same as in
	the uucp case; there's no simple means to
	resolve it, since this seems to be a kind
	of "religious" difference...


-- 
  ,u,	 Bruce Becker			Toronto, Ontario
a /i/	 Internet: bdb@becker.gts.org	Uucp: ...!web!becker!bdb
 `\o\-e
 _< /_	 	DO NOT TAUNT HAPPY FUN BUSH - H. R. Perotnoid
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