Re: Minneapolis - agenda items please.

[Rob Austein <sra@hactrn.net>]

At Tue, 26 Feb 2002 11:10:09 -0500, Donald Eastlake wrote:
> 
> Re below: not just universities. When I was at Digital Equipment Corp,
> there were cases of internal areas firewalled off from the rest of the
> corporate net which was firewalled from the Internet. It was common
> for the first MX to be for direct delivery, one or more second
> priority to be for delivery to mail servers on the inner firewall, and
> then several third priority for delivery to the main Digital firewall.
> An outside mail sender would thus have to always go thorugh a number
> of MXes before getting one that they could connect to. But this didn't
> seem to cause much problem. I'm sure that, over the years, millions of
> pieces of mail were delivered this way.

At the cost of some resources belonging to the people sending the
mail.  Anecdotal evidence goes back at least to the late '80s, when
WSMR-SIMTEL20.ARMY.MIL sometimes had nontrivial backlogs in its
outbound mail queue due to all the delays associated with trying all
those MX relays at sites that did this.  Yes, the mail got through
eventually, and yes, we've learned how to MTAs that are less sensitive
to this kind of problem, but since the situation would have been
completely avoidable if the zone admins hadn't listed all those
unreachable addresses, it's hard to avoid viewing it as (presumably
unwitting) anti-social behavior that's worth discouraging.

Completely gratuitous externalities considered harmful.