Path: utzoo!attcan!uunet!husc6!think!ames!amdahl!tron
From: tron@amdahl.uts.amdahl.com (Ronald S. Karr)
Newsgroups: comp.mail.uucp
Subject: Re: Routing mail through Digital's sites
Message-ID: <9eaRl9dX9T1010mFOkk@amdahl.uts.amdahl.com>
Date: 28 Jul 88 01:50:16 GMT
References: <616@bacchus.DEC.COM> <10005@e.ms.uky.edu> <4930@zodiac.UUCP> <10022@e.ms.uky.edu>
Reply-To: tron@amdahl.uts.amdahl.com (Ronald S. Karr)
Distribution: na
Organization: Amdahl Coup, UTS Products Hen house
Lines: 52

In article <4930@zodiac.UUCP> jordan@ads.com (Jordan Hayes) writes:
>David Herron <david@ms.uky.edu> comments on Brian Reid's
><reid@decwrl.dec.com> assertion that "This kind of pseudo-AI belongs in
>user agents, not transport.":
>
>	"That's a matter of opinion ..."

As somebody who is helping to write a complete mailer from the ground up,
I must say that this kind of intelligence definitely should not exist in
the user agent.

Why?

1.  The means for resolving addresses should be centralized.  When there
    exists more than one user agent on a system, there is only one
    reasonable means of centralizing the algorithm:  put it in the
    mailer.

2.  There is no reason to assume a specific model for performing
    hostname resolving, when pathalias is available.  Consider, for example the
    model for a site that is on the internet, has some local networks
    of its own, is connected to UUCP, and is the registered gateway for
    a set of UUCP-only sites.  To do this requires:

	a.  A file describing the paths to sites for which we perform
	    the gateway service.

	b.  Hostname resolution through name server queries.

	c.  Various other routers/hostname resolvers, to match your
	    internal networking systems.

	d.  A paths file describing the UUCP zone.

    In order for pathalias routing to occur in the user agent, a user
    agent would have to determine that a host could not be matched
    by any of steps a, b or c.

Question for those who advocate not having routing done in the mailer:

Consider a site which is not on the internet at all:  should the UA
also route for user@dom.ain addresses as well?  Remember that we are
discouraged from using the ARPAnet as a means of transmitting mail from
point A in the UUCP zone to point B in the UUCP zone.  If point B is
a domain address, then a site must find a path to B for this to work.
Should a UA do this even in the presence of a set of local area
networks that have a domain-based organization?
-- 
	tron	|-<=>-|		ARPAnet:  amdahl!tron@Sun.COM
      tron@uts.amdahl.com	UUCPnet:  {decwrl,sun,uunet}!amdahl!tron
[views above shouldn't be viewed as Amdahl views, or as views from Amdahl, or
 as Amdahl views views, or as views by Mr. Amdahl, or as views from his house]