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Path: utzoo!utgpu!water!watnot!watmath!clyde!cbatt!ucbvax!sdcsvax!ncr-sd!greg
From: greg@ncr-sd.UUCP
Newsgroups: comp.mail.uucp
Subject: Re: smail(8) questions
Message-ID: <1406@ncr-sd.SanDiego.NCR.COM>
Date: Thu, 5-Mar-87 18:14:49 EST
Article-I.D.: ncr-sd.1406
Posted: Thu Mar  5 18:14:49 1987
Date-Received: Sat, 7-Mar-87 02:10:43 EST
References: <550@hao.UCAR.EDU>
Reply-To: greg@ncr-sd.UUCP (Greg Noel)
Organization: NCR Corporation, Rancho Bernardo
Lines: 67
Keywords: rmail vs. smail, local mailer interface, From lines

In article <550@hao.UCAR.EDU> woods@hao.UCAR.EDU (Greg Woods) talks about some
problems he had in getting smail to work viably at his site.  He runs both UUCP
and an SMTP-based subnetwork and he had quite a bit of trouble getting traffic
to flow smoothly.

At one point, he complains:
>I feel that there must be a better way to get it to do what I want than this,
>but I could not find it. .....

And finally, he concludes:
>  Any hints and/or discussion is welcome.

I guess that this is by way of a discussion; I really don't have any hints
on how to deal with the current smail.

The basic problem is that you would like to be able to specify a transport
mechanism on a per-outbound-link basis.  We had a similar problem, so that's
exactly what we did.  In the pathalias input for those machines which have
a non-standard transport mechanism (i.e., not UUCP), we specify a different
mailer.  We have modified smail extensivly to handle the this concept and
invoke the appropriate mailer (the mailers are specified in a configuration
file, along with how to construct the command).

(Don't ask us for the modifications.  They were really quite major, and the
diff listing is larger than the source itself.  We have given the changes
back to Larry Auton; nag him to find out when they will be available.  Or
rather, \don't/ nag him; but you might politely let him know that you are
interested in such modifications and would like to see them incorporated.)

The only assumption that our smail makes is that the initial hop listed in
the pathalias data base is bang-routed, but this need not be passed to the
mailer in that form -- you can easily construct an @-address to be given to
the mailer if you wish.  For your example, you would like to say that mail
for localhost should be given to sendmail for delivery over SMTP.  Your
local pathalias input would say
	hao	SMTP:(HIGH)
	SMTP	localhost!(LOCAL)
which pathalias would turn into
	localhost	SMTP:localhost!%s
so that smail would look in its configuration file for a SMTP mailer to use.
This method is very flexible and extensible; for example, something that
Fred has asked about several times,
	decwrl	ARPA:(HIGH)
	ARPA	.com!(DEDICATED), .edu!(DEDICATED)
would yield
	.com	ARPA:%s
	.edu	ARPA:%s
which would cause any traffic for ARPAnet sites to use the ARPA mailer.
(Note that due to the address resolution rules, this route would only be
used if no better match was found, so domains in the UUCP Zone would be
matched elsewhere and presumably be routed over his UUCP links.)

But one thing, Greg -- you really do want your domain address in your return
path.  I agree that the format is not ideal (I would rather have the line say
"From greg [date] remote from ncr-sd.SanDiego.NCR.COM") but the format will
work compatibly with both old non-domain mailers and new domain mailers.  In
particular, it will work with the current crop of overly-smart ("smart-ass?")
mailers that try to re-route all mail that passes through them.  One of those
mailers might send ...!hao!woods into hyperspace, but should do something more
reasonable with ...!hao.ucar.edu!woods (I hope -- I also think such smart-ass
mailers should be ruthlessly eradicated).

Our modified smail, of course, caters to the maximum flexibility, and allows
the the From line to be constructed any way you wish.  Sometimes, I think we
made it \too/ flexible......
-- 
-- Greg Noel, NCR Rancho Bernardo     Greg.Noel@SanDiego.NCR.COM