Installed greylisting

Unhappy with the high amount of spam that was making it through to my mailbox, I enabled yet another trick to slow down spammers. This time, it was greylisting. The greylistd package makes it quite easy, although I don't quite like the offered script that will help you update your exim4.conf; it adds the (slightly expensive) greylist check to the begining of the ACL, before the (cheap) checks on email address validity, which is silly. Then again, of course it doesn't have any other choice, as my exim4.conf is handcrafted from the example.conf, and is quite different from an exim4.conf as it comes with the Debian package.

Anyway. The greylisting has been running for quite a while now, and it seems to work. Flawlessly. Haven't received a single uncaught spam mail since I installed the thing. And of course I still have some cards up my sleeves, should the spammers ever circumvent this particular countermeasure, too.