20 Jun
2011
20 Jun
'11
6:20 p.m.
Hi. I'm the guy who wrote the CEAS paper on greylisting.
URL ?
They don't have Google where you are, huh? http://www.ceas.cc/papers-2005/120.pdf
You're right, greylisting on a large system may not be efficient as it won't block everything and will eat-up quite a lot of system ressources. But it's a good start once basic protocol-checks have already eliminated the 80% amount of bullshit sent from botnets.
Most of us use DNSBLs like the CBL or Spamhaus XBL to catch the botnet mail. It's a lot easier to let them tune their protocol quirk checker than to do it myself. R's, John