Sebatino,
Obviously, SpamFoo isn't going to disclose the complete inner workings of its product. If it did, it would be much easier for competitors to replicate. That said, they do provide a very good high-level explanation of how the system works on their website.
What we do know is that SpamFoo uses an incredibly sophisticated scoring system that accounts for a wide variety of scenarios. This allows the system to continuously learn and adapt to incoming email while enabling both servers and users to train it over time.
No single person can significantly influence the overall system—only their own experience. Likewise, each user's actions contribute to and influence the experience at the domain/server level. This approach allows the system to improve collectively while preventing any individual from disproportionately affecting the results.
I would suggest implementing it in one of two ways:
- If you're already using Cyren and MessageSniffer, add SpamFoo with a weight of 5. This allows it to provide an extra push for messages that are already trending toward spam based on your existing antispam scores. Once you're satisfied with the results and decide to remove Cyren and/or MessageSniffer, simply increase SpamFoo's weight accordingly.
- If you're not using Cyren or MessageSniffer, give SpamFoo a weight of 15 and allow SmarterMail's built-in antispam features to contribute the additional scoring needed to classify messages as spam.
A combination of Greylisting, DKIM, SPF, RBLs, and URIBLs is extremely beneficial to an overall antispam strategy when used alongside SpamFoo—or any other third-party antispam solution.
I'm using our default scoring weights as examples, realizing that many of you have heavily customized your scoring or use a completely different scoring model for your environment.
As SpamFoo continues to learn, it will become even more accurate. Unlike RBLs and many other antispam features, which can cause significant disruption if a legitimate domain is mistakenly listed—especially when assigned a high weight—SpamFoo's effectiveness improves over time rather than becoming more susceptible to those types of issues.
If you would like to continue discussing the inner workings, please start another thread so that we can discuss things at a higher level for the overall audience of this thread.