Whitelist_clients file in postgrey

[openletter]

The file is used by postgrey, not postfix.

How to use Postgrey client whitelists

The Postfix Greylisting Policy Server (Postgrey) uses the concept of greylisting to take advantage of mail standards that the vast majority of spammers are not or cannot be configured to support. The postfix process is configured to send incoming mail to postgrey, which determines whether the mail can continue to the next step in the delivery process by checking whether the sender (“client”) or recipient match anything postgrey is configured to match. When the postgrey test fails, postfix will…