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Path: utzoo!watmath!clyde!burl!hou3c!wcwells%ucbopal.CC@Berkeley.ARPA
From: wcwells@ucbopal.CC (William C. Wells)
Newsgroups: net.mail.headers
Subject: Re: "blaming Unix SendMail"
Message-ID: <8407100223.AA18079@ucbopal.CC.Berkeley.ARPA>
Date: Mon, 9-Jul-84 22:23:29 EDT
Article-I.D.: hou3c.682
Posted: Mon Jul  9 22:23:29 1984
Date-Received: Wed, 11-Jul-84 01:06:06 EDT
Sender: ka@hou3c.UUCP (Kenneth Almquist)
Lines: 60
To: Header-People@MIT-MC.ARPA
Cc: postmaster@Berkeley

I would like to add to Mark Horton's reply:

	... For example, how should "a!b@c" be interpreted?
	"(a!b)@c" as required by the ARPANET?  "a!(b@c)" as required by
	existing UUCP software?

UUCP and Internet (ARPANET) mail address formats are not compatible.
Note that the "@" has is the primary delimiter in the
Internet mail world and that "!" is the primary delimiter in
the UUCP mail world.

UUCP Mail/Internet Mail gateways should be doing the address conversion
as follows: UUCP to LOCAL, then LOCAL to DOD Internet; and DOD Internet
to LOCAL, then LOCAL to DOD Internet (where LOCAL is a gateway domain
addressing scheme that provides for identification of different
external mail addresses).

If you are using sendmail, I suggest that you adopt the Internet
mail address format as your LOCAL format. Then in the
local mail domain you can use <uucp-address@uucp-neighbor.UUCP>
to identify UUCP addresses locally.

Here are some basic rules that a sendmail mail transport agent
acting as a gateway can follow to handle different address formats.

In the following examples "ucbvax" (@Berkeley) is a UUCP/Internet mail
gateway. And "b@c" is a valid Internet mail address. Note that
mail addresses are modified both at entering the local (gateway) mail
domain and when leaving the local mail domain.


Incoming from 		In the LOCAL		Outgoing to
UUCP mail		gateway domain		DOD Internet mail

From: x!y!z		From: y!z@x.UUCP	From: x!y!z@Berkeley.ARPA
To:   ucbvax!b@c	To:   b@c		To: b@c


Incoming from 		In the LOCAL		Outgoing to
DOD Internet mail 	gateway domain		UUCP mail

From: b@c		From: b@c		From: ucbvax!b@c
To: x!y!z@Berkeley.ARPA To:   y!z@x.UUCP	To: x!y!z


Note that there are two steps in the address conversion. First
the local mail agent information "ucbvax!" (from UUCP) or
"@Berkeley.ARPA" (from Internet) is stripped off, then the local
address remaining is interpreted.

For mail moving across the gateway, "@c" must be a full Internet mail
domain name.  That is a UUCP/Internet gateway should be strict about
only accepting complete addresses from non-local mail transport agents.
If "@c" is not a full domain name, then the gateway can only assume
that "@c" is in the local domain of the mail gateway.

Bill Wells
wcwells@Berkeley.ARPA
WCWELLS@UCBJADE.BITNET
ucbvax!wcwells