On Sat, Nov 25, 2006 at 09:23:49AM -0800, Marc Perkel wrote:
> In the early days
> there were almost no secondary MX servers.
Bullshit. In the early days there were a lot of secondary and even third and
fourth level MX hosts. Links were flaky and overloaded, systems were offline
(over night) and it was often a big gain to get the message e.g. over the
Atlantic bottleneck (in the night), so they could be delivered (over cheaper
links) within the country as the systems came back in the morning.
> Mail went from pine to smtp
In the early days there was no "pine". Mail went from "mail" or "elm"
to sendmail, sendmail sent on to e.g. campus wide gateways and those
made the WAN connections. Also pine does not do MX delivery IMHO, it
uses configured MSAs.
I agree that MTAs should try other MX hosts with the same distance as
the MX with the shortest distance on temp failure, but if one or more of
them are available and signal an error (be it permanent or temporary) the
sending MTA has to honor that and not send to MX hosts with larger distance.
I've seen MTAs (not spammers) not even honoring permanent error codes and
trying to deliver to other MTAs or backups instead. These programmers and
admins should be shot on sight.
Also your "idea" of the modified greylisting is pretty useless from my
experience, as the spammers either immediately try all available MX hosts
on errors anyway or they even start with the larger distance MX hosts first
(reverse MX algorithm) as the backup MX hosts have weaker policies and
usually don't know about users. That way the spammers get their mail
delivered and the burden is on the receivers and the faked senders get
all the bounces from the backups that cannot send to the primaries.
\Maex
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