Hello Ted,
> Changing the DNSBL verb from deny to drop may cause the bots to attempt
> the connection again, but this will depend on the bot. Some of them try
> again even with a deny, others try once and never come back again.
OK, so here's a "how" problem: would it be possible in Exim to first
send 5xx to client and then (almost) immediately drop the connection?
Anybody?