Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!purdue!tut.cis.ohio-state.edu!gem.mps.ohio-state.edu!ginosko!cs.utexas.edu!uunet!munnari.oz.au!murtoa.cs.mu.oz.au!ditmela!smart
From: smart@ditmela.oz (Robert Smart)
Newsgroups: comp.protocols.tcp-ip
Subject: MX-registration vs %-hack (was Re: New Host-Requirement RFCs)
Message-ID: <7696@ditmela.oz>
Date: 25 Oct 89 04:35:54 GMT
References: <8910201839.AA29376@arcturus.mitre.org> <1989Oct23.173855.1370@utzoo.uucp> <KARL.89Oct24124105@cheops.cis.ohio-state.edu>
Reply-To: smart@ditmela.oz.au (Robert Smart)
Organization: CSIRO, Division of Information Technology, Australia
Lines: 29

And of course it works the other way. MX-registration allows a host
with a proper domain name to be reached from the Internet. If the
Internet wants to be reachable from other networks they have to go
and ask those other networks to put in a gateway.

For example the Internet could ask ACSnet's minder to put in a gateway
from ACSnet to the Internet so that (for example) an ACSnet user
can send mail by

    sendfile -amailer user@host.university.edu <message

and it would magically work just as if host.university.edu was
a real part of ACSnet. This could be made to work. Perhaps the
Internet is too BIG and IMPORTANT to ask other networks to put in
gateways. In which case there seems to be a certain asymmetry in
arrangements.

Actually I don't see the problem. "user%node" is a perfectly legitimate
"local part" of an RFC-822 address, and I don't see why I shouldn't
set up my RFC-822 compliant domain to have that local part mean that
the mail should be forwarded to some local host that is too insignificant
to register. Certainly we shouldn't mandate that meaning of "%". If
other RFC-822 compliant domains want to have actual users with %s in
their names then that is also ok.

Bob Smart <munnari!ditmela.oz.au!smart> or <smart%ditmela.oz.au@uunet.uu.net>

P.S. I think I'll stick to %-hacked address in my signature until my
faith in the Domain System goes up a lot.