Mike Jackson escreveu:
Until the spammers build in retry into their bots, I'm a
firm believer of greylisting.
They have. I'm a sys admin at a major hosting provider, and I've seen
it in action on at least one customer's box who was using greylisting.
Considering spammers have near-infinite resources, it was only a
matter of time before they'd either retry delivery on the same
message, or simply wait an hour or so and try sending a new message.
But even with some spammers are starting to retry, greylist is still
a MAJOR antispam feature, which will block, in my experiences, more than
85-90% of all SPAMs received by the system.
I use policyd (http://policyd.sourceforge.net) as my greylist
daemon. It allows me to build blacklists based on reverse DNS of the
hosts, so I built some blacklists for getting
DSL/cable/dynamic/dialup/shitty networks worldwide. I also have built a
whitelist based also on reverse DNSs, which allows me to completly
whitelist all major ISPs worldwide and companies in my country (Brazil),
thus acchieving a 'no-greylist-delay' situation for a great amount of
messages sent by real servers.
With that, i'm pretty convinced that a HUGE ammount of SPAMs are
getting stopped on greylist level, avoiding those messages to reach
'heavier' antispam features after greylist, like SpamAssassim for
example. With whitelists, messages delay are not a big problem for the
users, because i successfully whitelist all major ISPs in my country.
--
Atenciosamente / Sincerily,
Leonardo Rodrigues
Solutti Tecnologia
http://www.solutti.com.br
Minha armadilha de SPAM, NÃO mandem email
[EMAIL PROTECTED]
My SPAMTRAP, do not email it
