As a follow-up to my previous entry about greylisting, here is what I used for the setup: the greylisting patch at Bill Shupp’s wonderful qmail related site.

I’ve made some modifications to his patch to allow for sender address and sender domain based whitelisting.
You can get my patch here:

large-qmail-patch_greylisting-katastrophos.net-20061023.patch

The dbdef.sql file includes an example of how to set up a whitelist filter for a specific sender domain or sender address.

The patch is against Bill’s Large Qmail Patch 0.8.3.