Misk.com Filtering Philosophy
Misk.com believes that the concept of having a Spam folder is completely ineffective, encourages bad software design, and results in more lost email than without it. In the marketplace, you'll find Spam filtering products that range in cost from free to thousands of dollars. What's surprising is that Spam filtering effectiveness varies and does not correlate to cost! Everyone says they're the best (with reports to prove it) and there's no way to really know without trying it yourself.
Lets face it. No one has time to check their Spam folder every day. A major pitfall that occurs from this is organizations then create filters that catch too much, thinking the email will go to the Spam folder if they make a mistake. This results in messages in your Spam folder that go unnoticed and give the impression of being delivered to the sender.
Our philosophy is focused on researching and implementing Spam filtering methods that filter out Spam while maintaining a very low "false positive" (mistakes) rate.
In addition, we ensure that all email we identify as Spam are rejected before being accepted into our mail server. This allows the sender to receive a bounced message from their mail server and therefore lets them realize that their message didn't get through (a huge problem in most Spam filtering methods).
This layer is responsible for rejecting between 60 and 90% of incoming messages depending on spam volume on any given day before they even reach our customers. That means right off the bat we know more than half your email is Spam!)
This layer utilizes public lists of verified Spam sources and computers infected with illegal 3rd party exploits, including open proxies (HTTP, socks, AnalogX, wingate, etc.), worms/viruses with built-in Spam engines, and other types of trojan-horse exploits.
Even though our first layer filters out over half of all messages received as Spam, our developers weren't satisfied. Developed in-house, this second layer is our own special tested cocktail of various spam fighting methods, which keeps changing as our spammers change their tactics.
Some of our current methods include including checking against an internal known spammers list, checking for common spammer links in emails, checking for image spam, smtp protocol tests, and a number our own secret tests and methods that seem to be working well!
As you know we're very serious about "false positives" and messages that hit this rules are rejected inline, which means the sender should receive a bounced email from their mail server. This helps ensure in the off change there is a false positive, the sunder knows to get in touch with you another way. No one else does this because most rely on spam folders, quarantines, and ineffective filters!
Note, we don't use the open source free software Spam Assassin, which most of our competitors offer as part of their solution. Spam Assassin is a great piece of software, but the industry has changed quite a bit since it was originally developed and our testing has found that content and bayesian based filters are rampant with false positives and low spam catch rates.