- Enable RBLs and DBLs. zen.spamhaus.org is the best way to block the
majority of junk before it reaches SA. Just make sure you are below their
free threshold limit. One important way to do this is
"One important way to do this" in terms of the Spamhaus threshold limit
is to not be such a tightwad and poney up for the Spamhaus commercial
service. ;-)
They do a cheaper version than the RSync feed, you can just query their
servers directly.
Spamhaus do a fantastic job. They deserve charitable donations from
generous mail sysadmins !!!
- Enable greylisting.
Ewww...
I hate people who operate graylisting. Its a lazy "tarnish everyone
with the same brush" approach to anti-spam.
In this day and age, you don't need it. Decent network checks, properly
configured Spamassassin and you should be able to achieve a very
respectable spam catching rate.
