I recently set up one of my lists (big-linux) to be delivered using another
internet host using the internet-via keyword.  My assumption was that
listserv would do either one of two things to implement this:
 
1)look up the address of the host listed in internet-via and make a direct SMTP
connection.  (Less likely, was my intuition, because listserv prides itself
on not being an MTA (A good thing)).
 
2)tell sendmail on my machine to accept all the messages that it had to
deliver, but instead of telling sendmail to deliver them itself, tell it to
use a different host (the one listed in Internet-Via).
 
I thought the second option was a lot more likely until I sat here and
wrote it down in this message.  There's no way to tell sendmail which host
to use as a relay using SMTP, so it'd have to be a command line option, and
then listserv would depend very strongly on the use of a particular
incarnation of sendmail.  Bad design.  I'm now more inclined to believe
that the first method makes more sense, but only because the first mailing
list program that I used was Listproc, and it uses SMTP for everything.
 
However, it seems that the way Internet-Via is being used is by way of the
DISTRIBUTE mechanism.  Here are the headers for a recent message sent over
big-linux.  The history of the message is recorded from most recent to
least recent, and I have included headers down to where the original poster
sent the message.
 
Received: from theforce.cis.temple.edu (theforce.cis.temple.edu
[129.32.32.55]) by netspace.org (8.6.10/8.6.9) with ESMTP id PAA15584; Mon,
24 Jul 1995 15:35:12 -0400
Received: from VM.TEMPLE.EDU (vm.temple.edu [155.247.14.2]) by
theforce.cis.temple.edu (8.6.11/8.6.9) with SMTP id IAA06632; Mon, 24 Jul
1995 08:19:45 -0400
Received: from VM.TEMPLE.EDU by VM.TEMPLE.EDU (IBM VM SMTP V2R2)
   with BSMTP id 1060; Mon, 24 Jul 95 15:24:16 EDT
Received: from VM.TEMPLE.EDU (NJE origin LISTSERV@TEMPLEVM) by
VM.TEMPLE.EDU (LMail V1.2a/1.8a) with BSMTP id 6299; Mon, 24 Jul 1995
15:24:15 -0400
Received: from NETSPACE.ORG by NETSPACE.ORG (LISTSERV-TCP/IP release 1.8b) with
          spool id 160188 for [log in to unmask]; Mon, 24 Jul 1995 15:24:00
          -0400
Received: from marge.cyber-dyne.com (marge.cyber-dyne.com [198.68.8.1]) by
          netspace.org (8.6.10/8.6.9) with ESMTP id PAA14775 for
          <[log in to unmask]>; Mon, 24 Jul 1995 15:23:27 -0400
Received: (from ruschein@localhost) by marge.cyber-dyne.com (8.6.10/8.6.9) id
          MAA11774 for [log in to unmask]; Mon, 24 Jul 1995 12:12:36 -0700
 
Theforce.cis.temple.edu is the internet-via host.  NetSpace.org is both the
host of the list and the domain for my address, which is why it appears in
the middle of the headers (when listserv proccessed the list) and at the
top (when I received the message).  VM.Temple.edu is undoubtedly being used
to transfer the message from netspace to theforce, probably because of some
routing table that listserv has, probably related to the DISTRIBUTE
algorithm.
 
I find this particular behavior disconcerting.  Perhaps I am not using the
internet-via keyword as it was originally designed.  My goal is to use
internet-via to systematically, and in spite of what listserv thinks is
more efficient, design a distribution network for the mailing lists run out
of netspace.  The owners of theforce will almost certainly allow traffic
from Big-linux and Bugtraq to use cycles and network time on their machine
-- they might not allow the Indigo Girls list to do so.  However, there are
Indigo girls fans in high places as well, and I can use their machines to
distribute Indigo-Girls mail.  In this way I can move the load of
distributing mail off of the already struggling netspace.org and onto a
variety of sympathetic systems.
 
Internet-Via seems to be designed to give a listowner on a bitnet-only host
their choice of internet gateway.  I'm not sure why this was done --
wouldn't/shouldn't the bitnet host itself know about the best internet
gateway?
 
Regardless, I don't have permission to route all the mail from big-linux
through vm.temple.edu, and I suspect I'll have to abandon this mechanism of
distributing load if I can't find some way to go around it.
 
How can I force listserv to go directly to theforce.cis.temple.edu, instead
of through vm.temple.edu?
 
Also, while I'm here, can I use service areas to make sure that mail
destined for folks on netspace doesn't get routed through theforce, but
rather gets delivered immediately?
 
Lee Silverman     [log in to unmask]      http://www.netspace.org/users/lee/
         Live each day as if your life had just begun.  --  Goethe