Comment Re:Flawed statistics are flawed (Score 1) 114
They probably check what's passing through the upstream filters, and is handled by a spamfilter.
My spam filter catches some 45-50 spams a day. It misses those with attachments (irritating - get 5-10 of those daily) and a few others that are hard to classify as spam (rather legit business related but not my business), but overall doing a decent job. I'm getting a similar number of legit mails a day, a large number of those being stuff like meetup and facebook status messages. So that'd be indeed about half/half for spam vs ham.
However, that 45-50 spam a day is AFTER greylisting, which basically requires every first-time sender (FROM, TO, source IP) to retry 5-30 minutes later. Many spambots just don't. I have this active for years, and when I installed it the amount of caught junk went down from some 300 a day to 30 a day. If this 10-fold difference is still the case, I'd be getting some 450-500 spam a day, or a 90% spam to 10% ham ratio. I'm not about to switch off greylisting to try this out, though