Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!ucbcad!ucbvax!PURDUE.EDU!narten
From: narten@PURDUE.EDU.UUCP
Newsgroups: mod.protocols.tcp-ip
Subject: Re: Tcp/Ip vs a store & forward network
Message-ID: <8704030246.AA02484@gwen.cs.purdue.edu>
Date: Thu, 2-Apr-87 21:45:55 EST
Article-I.D.: gwen.8704030246.AA02484
Posted: Thu Apr  2 21:45:55 1987
Date-Received: Sat, 4-Apr-87 18:36:58 EST
References: <8704010458.AA01350@spam.istc.sri.com>
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
Lines: 24
Approved: tcp-ip@sri-nic.arpa

>     Presumably, as domain names get extended, we will be able to
>     do that.  Any mail you send to a user can go directly to the machine
>     where the his/her mailbox resides. No forwarding at the site would be
>     needed.

There is still a hole with current TCP mailers in that often mail
really travels an extra hop. That is, mail for janedoe@somewhere.edu
gets sent to the machine at "somewhere.edu", which after accepting the
mail, turns around and forwards it the machine the user reads mail on.
I would prefer an acknowledgement that mail has actually been placed
in the users mailbox, rather than just handing the mail to a
"reliable" delivering agent at the site.

Domain names were designed to handle lots more than just machine name
to IP address mappings. At some point, it will (hopefully) be possible
to register mailboxes in the system. That way, mail sent to
janedoe@somewhere.edu will not necessarily mean sending the mail to
"somewhere.edu". Rather, sendmail will find the real agent via
nameserver queries about "janedoe@somewhere.edu".  Now mail gets sent
directly to the machine where the user's mailbox resides, and now when
the mail is no longer in the sender's local queue, it really is in the
correct mailbox, and not still in transit somewhere.

Thomas