Hi Y'all

One of my clients is asking for better spam filtering. Right now, I have:
bl.spamcop.net
blackholes.mail-abuse.org
cbl.abuseat.org
dnsbl-1.uceprotect.net
dnsbl-2.uceprotect.net
dnsbl-3.uceprotect.net
l2.dsbl.org
zen.spamhaus.org
which is blocking between 60% and 80%. Is there a better list? Would
SpamAssassin be better? Is this as good as it gets and it's time for a
subscription?

Thanks
Bob Crandell