15 Dec
2006
15 Dec
'06
11:01 a.m.
Also, it can be configured
to also verify the incoming addresses at the remote MX (which is likely
not the bot, thus it will discard such unauthorized sendings as well). I
use it at our central mail gateway with good success, as the vast
majority of valid mail severs meanwhile are RFC compliant.
I've been also being strict about forged hosts, i.e., when you do a reverse
lookup on the IP, and then forward lookup the reverse PTR, the IP should be
there. This has helped a lot, and doesn't impact the common situation where
a host (usually a home static IP) has a legitimate domain, but its PTR is
that of the network upstream (as long as that PTR resolves).
--
--------------------------------- personal: http://www.armory.com/~spectre/ ---
Cameron Kaiser * Floodgap Systems * www.floodgap.com * ckaiser at floodgap.com
-- Proponents of other opinions will be merrily beaten to a bloody pulp. ------