On Tue, 2005-12-06 at 10:18, Feizhou wrote: > Rodrigo Barbosa wrote: > > -----BEGIN PGP SIGNED MESSAGE----- > > Hash: SHA1 > > > > On Tue, Dec 06, 2005 at 10:27:24PM +0800, Feizhou wrote: > > > > That depends on how you see it. If you are thinking about the spam ratio, > > yes, you are correct. RBLs can filter up to 90% of all the spam (in my > > experience). On the other hand, if you are being targeted by 1000's of > > spams daily, you will still get a fair number of them. > > > More than 90% is possible in mine :) and it is also a case of being > targeted... > > Content filtering for spam is one of the worst things to do. > That is why I like greylisting. Very little resources required and in my experience it blocks 98% or better of the spam I see. Prior to that there would be days when a spam storm would hit and backup email for several hours. Spamassassin did a good job of sorting it out but it took all of the systems resources to handle it. And with greylisting you are not dependent on someone else's RBL lists or connectivity to a system somewhere on the Internet. Once setup it has required little if any additional admin work to keep it running. It actually allowed me to pretty much get out of the business of fighting spam which had started to consume a large amount of my time. And with the combination of greylisting and spamassassin it is rare that any spam gets through to an end user.