In addition to pyzor & razor what else do you have set?
To cut down on emails to addresses you don't even have, you might also change the entry in /opt/zimbra/conf/zmmta.cf for smtpd_reject_unlisted_recipients to 'yes', save the file and restart postfix. (postfix reload)
You do any realtime blacklists? (Just remembered that their in a
different doc than the improving anti-spam one.)
sbl.spamhaus.org (or zen.spamhaus.org contains 3 lists)
dnsbl.njabl.org
cbl.abuseat.org
bl.spamcop.net
dnsbl.sorbs.net
you can enable them by:
Code:
zmprov mcf +zimbraMtaRestriction "reject_rbl_client bl.spamcop.net"
I also use
dnsblcount to get some totals - nothing fancy on those summaries, but makes you feel like something's being done!
Graylisting (I'm a fan)
Graylisting - Improving Anti-spam system - Zimbra :: Wiki
Host checks:
reject_invalid_hostname
reject_non_fqdn_hostname
reject_non_fqdn_sender
DNS checks:
reject_unknown_client
reject_unknown_hostname
reject_unknown_sender_domain
-careful with reject_unknown_client & reject_unknown_hostname as they can block more than you think sometimes...
Code:
zmprov mcf +zimbraMtaRestriction reject_invalid_hostname
Occasionally your ALW might need a kick if you got off on the wrong foot or something:
Correcting poisoned Auto-Whitelist (AWL)