Utilizzo di una whitelist in Postfix per abilitare indirizzi email bloccati da una Blacklist antispam

Dalla FAQ 68 di Postfix:

I'm using one of the blacklists to block spam and it's working fine. Now one of our customers/partners has got themselves listed, so my mail server is dutifully rejecting their messages. Is there a way to allow just their messages but still use the blacklist?

You can create a whitelist that will accept messages from certain addresses or domains. For example:

#
# main.cf
#
smtpd_recipient_restrictions =
	permit_mynetworks
	reject_unauth_destination
	...
	check_sender_access hash:/etc/postfix/whitelist 
	reject_rbl_client dnsbl.njabl.org
	...

Il file whitelist sarà:

#
# whitelist
#
@customer_domain.com	OK

Make sure the whitelist check occurs before the reject_rbl_client check.

Remember that email addresses are easily faked.

Whenever you add whitelisting to your configuration be very careful that you don't expose your server to open relaying.

Make sure that your whitelisting occurs after reject_unauth_destination (or another rejection restriction).