The more SPAM stays the same, the more ways they find to get it through to your mailbox.
How we determine something to be SPAM vs legitimate mail is a bit of a science and it incorporates a ton of statistical analysis, data feeds, real-time blacklists, IP reputation scores, several antivirus products, several malware detection products, subscription services, etc. We pass each inbound message through almost all of these subsystems and assign it a score – as that score adds up the message becomes categorized as SPAM or SureSPAM based on the amount of UCE/malware/infected content the message has.
Every year we rebuild the ExchangeDefender engine to pull out things that no longer perform well, add new promising technologies, shift around the different plugins and so on. While ExchangeDefender filtering is updated in real-time and by tons of different vendors along with our in house technology, major improvements and technology shifts are necessary in order to prevent truly dangerous stuff from getting through. Unfortunately, this means that for about a week or two the amount of junk mail that gets through goes up as we reset all our scores, statistical models, weighs for different services and the implementation. While we wish we could just point and click, the process is far more complex than that, and requires delicate changes over a few days.
We appreciate your patience with us as we get the new engine online. The SPAM filtering levels should return to 100% shortly and we realize SPAM is annoying – which is why we’re doing this in the first place. Thank you for your business and trusting us with your email, we look forward to getting our best ever SPAM detection online shortly.