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Path: utzoo!linus!decvax!ittvax!dcdwest!sdcsvax!sdcc3!brian
From: brian@sdcc3.UUCP (Brian Kantor)
Newsgroups: net.mail
Subject: Re: path optimizing in sendmail
Message-ID: <2463@sdcc3.UUCP>
Date: Thu, 8-Nov-84 18:45:47 EST
Article-I.D.: sdcc3.2463
Posted: Thu Nov  8 18:45:47 1984
Date-Received: Sat, 10-Nov-84 03:48:38 EST
References: <1836@nsc.UUCP>
Distribution: net
Organization: UCSD wombat breeding society
Lines: 47

> I'm starting to look seriously at doing some limited path optimizing in
> sendmail.
> I'm interested in hearing what my approach may break out in the real world
> before I get started, and any other comments you might have. My overriding
> priorities is to not break existing software, at least not without knowing
> what I'm doing, but I also don't want sendmail doing hidden optimization,
> the user should be able to override it if he wants to...

What I have decided to do (as soon as I have time [heh heh heh]) is to
add path optimization to sendmail in this form:

	if the options line in .mailrc says noopt then do nothing

	if the address has a bang in it (farkle!wombat!plaid) then leave
	it alone.

	if the address is in internet format (brian@wombat) or in
	internet form with a domain that we can talk to directly (such
	as plaid@nsc.uucp), I will look it up in a routing table (built
	from uucpmaps, host tables, and holy water) and substitute the
	address that we think is the best path.

	if the address is in internet format for a domain where we
	don't know the host but we do know the domain server (such as
	gnu@raphael.sun.uucp) we will ship it to that domain server (in
	this case it would be addressed as ...ucbvax!sun!gnu@raphael).

	if the address is in internet format but we don't know the
	host (or domain & host if both are specified) then we'll bounce
	it back to the sender with some sort of chastizing message.

For replies to news articles, which seem to account for about 1/2 of our
off-site traffic, we will first do the above with the 'From:' line.  If
that does not resolve to a usable address, then we'll start looking at
the rightmost site name in the 'From ' line and work leftwards until we
find a site name we can get to with fewer hops, and send it that way.
If that doesn't work, it will just be sent with the address originally
provided.

I haven't even started to design much of this.  So don't ask for a copy
of the code because I'm likely to get hit by a car before I get it done.
Glad to discuss it with anyone, if they would like.

From the lonely keyboard of:	
	decvax\ 	brian@sdcsvax.arpa
	akgua  >---  sdcsvax  --- brian
	ucbvax/		Kantor@Nosc