Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site hou3c.UUCP
Path: utzoo!watmath!clyde!burl!hou3c!wcwells%ucbopal.CC@Berkeley.ARPA
From: wcwells%ucbopal.CC@Berkeley.ARPA (William C. Wells)
Newsgroups: net.mail.headers
Subject: Re:  smtp, errors and delivery
Message-ID: <8403081948.AA02084@ucbopal.CC.Berkeley.ARPA>
Date: Thu, 8-Mar-84 14:48:17 EST
Article-I.D.: hou3c.401
Posted: Thu Mar  8 14:48:17 1984
Date-Received: Sat, 10-Mar-84 10:31:26 EST
Sender: ka@hou3c.UUCP (Kenneth Almquist)
Lines: 41
To: Header-People@MIT-MC

Military message systems operate on three basic principles: reliability,
speed, and security. Of the three, "reliability is paramount".
I think you will find that an electronic mail system that permits
messages to "drop into a black hole" will not be acceptable for
Defense Data Network (ie. MILNET) use.

Mail transport agents should be responsible for ensuring the FROM in
SMTP and the "From" in the mail header are correct both when received
and when transmitted.  This may require that gateway mail transport
agents modify the address when the message is transmitted by a gateway
into a different mail domain or mail system.  For non-Internet mail
addresses, this means transforming the address into an address that is
acceptable to the Internet world.  It may mean adding  the source
"route" (eg. @host.domain:) of the gateway mail transport agent to the
front of the From address, or changing the address into the form:

   "off-net-address"@mail-gateway-id.registered-top-domain-name

where the address to the right of the "@" sign is a valid Internet
mail domain name.

Receiving mail transport agents should check the FROM field, if the
syntax is correct, but the domain name is not, then they should add
the domain name of the sending mail transport agent to the front of
the source "route" in the address to ensure a reply path. --- Hmmmm.
That would imply the addresses of the form:

   <@mail-gate.Internet-top-domain:local-address@hostid.non-ARPA-domain-name>

for example:

   <@mail-relay.ARPA:userid@hostid.local-netid>

should be legal within the Internet mail world. That is, if the
first domain-name in the source "route" is known and valid within the
current mail domain, and the syntax of the address is correct,
then the address should be accepted by the receiving mail transport
agent.

Bill Wells, Computing Services, UC Berkeley
wcwells@Berkeley.ARPA or ...!ucbvax!wcwells