If you are using RBLs (such as zen.spamhaus.org) to block spam, the whitelist method in the Wiki does not work. This is because the wiki method is for spamassasin not postfix.

Postfix will check incoming messages against the RBL first, and allow/reject accordingly. So if you have a sender listed on a RBL, you need to whitelist them in Postfix.

Using this post: How To Whitelist Hosts/IP Addresses In Postfix | HowtoForge - Linux Howtos and Tutorials

I came up with a method to do this in Zimbra. {commands in italics}

Login and change to zimbra user

vi /opt/zimbra/conf/postfix_rbl_override
list all IP addresses or host names (one per line!) that you want to whitelist:
Code:
1.2.3.4 OK
1.2.3.5 OK
mail.freemailer.tld OK
postmap /opt/zimbra/conf/postfix_rbl_override

vi /opt/zimbra/conf/postfix_recipient_restrictions.cf

under:
reject_unauth_destination
add:
check_client_access hash:/opt/zimbra/conf/postfix_rbl_override

e.g.:
Code:
reject_unauth_destination
check_client_access hash:/opt/zimbra/conf/postfix_rbl_override
reject_unlisted_recipient
zmmtactl restart

Each time you add a new one, you need to do the postmap command then zmmtactl restart

Bertie