==== Required information ====
- iRedMail version: 0.8.4
- Store mail accounts in which backend (LDAP/MySQL/PGSQL): Mysql
- Linux/BSD distribution name and version: debian/squeeze
- Related log if you're reporting an issue:
====

Zhang,

Are you talking about Sender White-listing or Recipient White-listing in the following thread ?
http://www.iredmail.org/forum/post21835.html#p21835

http://policyd.sourceforge.net/readme.html
The url you sent says that :
    Please note that address whitelist will be matched only against
    the  sender address. For recipient  whitelisting,  please refer
    to the opt-in/opt-out section below.

In my case, I am the recipient (abc@mydomain.org). There is an email sender john@bank.com, which is getting rejected by my server because of greylist=new and john's server doesn't try again. But John is not a spammer. So I want to whitelist John.

So I think the solution is "Sender Whitelisting" in the above readme url.

Please clarify. Thanks.