<snip>
> > # DNSBL lookup latency - stuff like djb's rbldns
> > (http://cr.yp.to/djbdns/rbldns.html) should help.
>
> This could be the reason though. I suppose there's a time-out for the
> DNSBL lookup... Philip?
>
You mean, if a spammer managed to sufficiently load the relevant DNSBL server (for example, by sending out a lot of spam to MTA's
that check the DNSBL), then, due to the resulting DNS timeouts, some of the spam might get through? Kind of like overwhelming a dam
with too much water? hmmm... Gotta have a reasonable timeout on DNS lookups, or one bad apple could ruin your whole day...
hmmm...
The only thing I can think of, would be to temporarily reject if a DNSBL check times out. For all I know, Exim may already do that,
but would be good to know, either way.
Any other ideas?
Jim Roberts
Punster Productions, Inc.
