I had to setup my own whitelists for my Postfix installation. Bigpond is one example of somebody who gets listed in RBL blacklists often, and well they don’t attempt spam against me all that often but do send alot of legitimate e-mail my way, so it deserves a whitelist entry.
On Debian to setup a whitelist all you have to do is edit /etc/postfix/main.cf so that smtpd_client_restrictions includes something like ‘check_client_access hash:/path/to/rbl_override’
For example this is what I have in my /etc/postfix/main.cf:
smtpd_client_restrictions = permit_sasl_authenticated, permit_mynetworks, check_client_access hash:/path/to/rbl_override, reject_rbl_client tor.dnsbl.sectoor.de, reject_rbl_client dnsbl.ahbl.org, reject_rbl_client dnsbl.sorbs.net, reject_rbl_client zen.spamhaus.org, permit
Some hosts use SPF records in DNS to specify what mail servers are safe to accept e-mail from. To lookup this information you can run:
host -txt bigpond.com
Then you need to create your rbl_override file. It should have something like this:
# Bigpond (taken from `host -t txt bigpond.com`)
You will also need to run postmap on the rbl_override file, to create a machine parse able binary with your whitelist database.
My Postfix installation is spread across several servers, however through a rig with rsync I regularly synchronize some binaries and configs to every server so I simply use this to send my whitelist.