[Greylist-users] Greylisting with automatic IP address based whitelist

[Akihiro KAYAMA]

Thanks for your replies. I got understand why IP address based
whitelist is not embedded into Greylisting.

And, still I feel it is useful. So I try to explain.

My purpose using Greylisting is to reduce spams received via open
proxies, because most of spams are comes from open proxies in these
days. I does not intend to shut down ALL spams by Greylisting. Anyway,
Greylisting can't block spams via open relays and ISP's legitimate
server which run legitimate MTA.

As making barriers higher, legitimate mails as well as spams are more
delayed or even occasionally blocked. It is a trade-off. I found
Greylisting is so powerful that there is room for trade-off to
minimizing negative impacts. IP address based whitelist is one of
trade-off. This increase a bit of spam rates, but significantly
decrease delays. Greylisting still remains powerful(90% spams are
blocked), this seemed to be a good choice for me.

Yes, my company is small. We receive average 800 mails/day only. Our
best solutions will be different from the ones for large ISPs'. But
Greylisting should be a real boon to everyone from ISPs to
individuals(who have own MX hosts).  I want Greylisting to be more
common.  Even if some variant approach is suitable only for small
organization, I want to know it because it might be suitable for me
and my friends.

-- kayama