On 20-nov-2006, at 23:33, Vahric MUHTARYAN wrote:
Hello Everybody,
I'm using SA for a long time without any problem, nowadays
spammers are using too much graphical objects and they are tring to
change it day by day. I'm tring to use fuzzyocr but it's taking too
much cpu. I think that try greylisting . I wonder are there anybody
use greylisting ? Somebody can give me feedback ?
I started using selective greylisting a while ago and the results
are simply amazing. For instance, my private mailbox has gone
from receiving 75-100 spams/day to 2-4 spams/day. Selective
greylisting is a variant of "pure" greylisting where you don't greylist
everything, but only "suspicious" smtp clients.
I'm using maRBL (written by Ian Campbell) for this, which acts
as a policy service for Postfix. It greylists clients based on DNSBL
lookups. maRBL used to be available from
http://www.orangegroove.net/code/marbl/, but the site seems
to have disappeared....
I'm actually using a modified version of maRBL, using a patch by
Mark Martinec (of amavisd fame) that integrates p0f support to
selectively greylist Windows smtp clients:
http://archives.neohapsis.com/archives/postfix/2006-11/0577.html,
which is both brilliant and hilarious :-)
I have also added (primitive) support for greylisting based on missing
PTR records and SPF checks myself (it actually rejects if SPF fails
hard).
I have put the three versions of maRBL available for download on my
server: http://leander.koornneef.net/marbl/
Perhaps it can be of use to anyone. And thanks to Ian and Mark!
Leander
