BorderWare is making a very interesting claim. It seems to be blocking an enormous proportion of its customers' inbound spam simply using IP reputation.
While most anti-spam vendors these days talk about blocking roughly 75% of the spam using IP reputation (basically a fancy word for DNSBLs), BorderWare's quoted statistic is 98.3%. Wow, that's a lot -- especially considering that the law of diminishing returns almost certainly applies.
This is a good thing because the more spam one can identify and block by reputation, the less spam content one has to examine using techniques such as Bayesian analysis, which are computationally "expensive".
But how does the company achieve such a high figure? By slashing the time taken for new entries to be added to its centralized reputation database (BSN, or "BorderWare Security Network" -- soon to be rebranded as "Reputation Authority").
These days, new zombie spam sources don't hang around to be detected, they get sending as soon and as fast as they can -- the botmasters have realized that a fresh, undetected spam source is far more effective than an old, known source. Minutes count; in fact in the spameconomy, time is money.