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From: reid@Glacier.ARPA (Brian Reid)
Newsgroups: net.mail
Subject: automatic address rewriting by smart gateways
Message-ID: <10077@Glacier.ARPA>
Date: Sat, 27-Jul-85 13:59:11 EDT
Article-I.D.: Glacier.10077
Posted: Sat Jul 27 13:59:11 1985
Date-Received: Sun, 28-Jul-85 07:15:48 EDT
References: <568@decuac.UUCP> <531@down.FUN> <570@decuac.UUCP> <537@down.FUN> <9390@ucbvax.ARPA>
Reply-To: reid@Glacier.UUCP (Brian Reid)
Organization: Stanford University, Computer Systems Lab
Lines: 58
Summary: it's a commie plot to cripple US netmail communications forever

I've always admired Peter Honeyman and his friends for being so successful
at using intellectual terrorist tactics to squelch most criticism of their
ideas. Usually when groups resort to this kind of ad hominem argot, the
world stops paying any attention to them. But in addition to being
terrorists, the Honeyman gang often know what they are talking about. It's
therefore always dangerous to disagree with Peter in public, because your
mailbox will fill up with letterbombs (though the letterbombs always have
malformed headers and a smart mail-reading program can just ignore
them......)

Anyhow, I'd like to take the dangerous step of disagreeing with Peter that
automatic rewriting of addresses is a good idea. My network home is at the
confluence of several networks (arpa, uucp, PUP ethernet) and 1 hop away
from several more (bitnet, DEC Enet, Xerox clearinghouse, etc.) I send,
receive, and provide postmaster services for an awesome amount of mail that
crosses "domain" (pardon the expression) boundaries.

Automatic address rewriting in the current mail world has the problem that
it doesn't know what addresses to rewrite, and cannot. Furthermore, it makes
it impossible for a person to know his own address. If I send you a message
to honey%down@princeton, somebody's mailer can rewrite it so you see a
message sent to princeton!down!honey. But what if the message has a CC
field? Do you rewrite that? You will quickly answer "yes", of course,
because you do. Though some probably don't believe in the existence of CC
fields--smacks too much of the dreaded arpanet. If you have a religious
belief that messages should not have certain header fields (or should not
have headers), then how do you handle translation to and from these headers.

But that is the easy part. The hard part is addresses passed as data, or
written down on pieces of paper. If I get a message from
DSITES%null.DEC@Decwrl.ARPA, and I forward the message to you, the message
that I am forwarding will not be subjected to any kind of address
translation, because it is just text, and not message headers. If you are a
smart guy like Peter Honeyman, you will know how to translate manually the
address that you see in the message.  But let's suppose that you are a
typical sort of AT&T employee who isn't even capable of learning not to post
"house for sale in NJ" ads on net.general. What are you going to do with
that address? Probably just send to it, trusting that some smart gateway
will get it right. What if you are at a conference and somebody asks you for
your mail address. What do you tell him? Well, you ask him for his mail
address, and then based on what he tells you, you mentally translate your
address into the vernacular of his network, so that he can mail to it. But
what if he is playing the same trick that you are, waiting to know your
address before he can tell you his.

Automatic address translation creates context-sensitive addresses.
Context-sensitive addresses are bad. It behooves addresses to be universal.
Current mail technology makes universal addresses impossible. I claim that
any technological solution (such as automatic rewriting gateways) that
serves to prolong the existing situation (total chaos) is bad.

Can you imagine how awful things would be if the telephone system used the
same kind of addressing scheme that the techno-zealots at the phone company
are trying to foist on the computer mail world? And you thought MCI with
access codes was bad....
-- 
	Brian Reid	decwrl!glacier!reid
	Stanford	reid@SU-Glacier.ARPA