See also Zimbra Antivirus and Antispam

See also Zimbra DKIM Configuration

https://wiki.zimbra.com/wiki/New_Features_ZCS_8.5

https://wiki.zimbra.com/wiki/Improving_Anti-spam_system

Howto: http://shahzadlinux.blogspot.com/2016/03/how-to-blacklist-or-whitelist-ip.html

This will affect all users!

As root:

vim /opt/zimbra/data/spamassassin/localrules/sauser.cf

Add at the bottom, modifying for your needs:

## Black and White List
whitelist_from statistics@reporting.smtproutes.com
blacklist_from spammer@example.com

Restart the filter:

zmamavisdctl restart

• spammer@example.com - blocks all email from spammer@example.com
• example.com - blocks all email from ANY address at example.com

In a pinch, you can add an IP address to the Postfix mynetworks definition of trusted hosts.

Become the zimbra user:

su - zimbra

vim /opt/zimbra/conf/postfix_rbl_override

xxx.xxx.xxx.xxx OK

then:

postmap /opt/zimbra/conf/postfix_rbl_override

zmprov mcf +zimbraMtaRestriction 'check_client_access lmdb:/opt/zimbra/conf/postfix_rbl_override'

vim /opt/zimbra/conf/postfix_blacklist

xxx.xxx.xxx.xxx REJECT

then:

postmap /opt/zimbra/conf/postfix_blacklist

zmprov mcf +zimbraMtaRestriction 'check_client_access lmdb:/opt/zimbra/conf/postfix_blacklist'

zmmtactl restart