I have a strange problem with mail server

[kilburn]

Well, some points:

(1) Postgrey already implements a cache, so that the same combination of (ip.of.remote.server, sender, recipient) is not greylisted twice within a period of time (days).

(2) You should not be greylisted by your server if you send through it and authenticate properly.

(3) You can setup a client whitelist to avoid policyd-weight and postgrey checks for some IPs.