How SpamAssassin works
Spam usually contains certain words, web addresses, and various other tricks. They are called “Patterns”. SpamAssassin has a huge database of such behavior patterns, and every pattern is given a score. The result is a “spam score” which you can see in every email you receive through NSA (if you look at the mail headers with your favorite mail software). We have 3 score thresholds: above 10, above 14, and above 99. This is how it works:
- 10: Uncertainty Threshold – Emails with a spam score of above 10 will only be marked as possible spam. You will still receive them because between 10 to 14 we can not be 100% certain that it is indeed spam.
- 14: Certainty Threshold – Emails with a spam score of 14 or higher will be moved to your “Junk” folder. Please note that we never really reject
- 99: Rejection Threshold – Emails with a spam score of 99 or higher will be rejected. You are not likely to ever receive them again. The reasoning is that a spam score of 99 is so high that there is absolutely no question that the mail is spam.
Once in a while, we conduct a survey among our customers and we modify these values in order to further improve the rejection and detection thresholds. If you find that over 99% of emails you receive are marked as (“Spam?”) in the subject (which means we are hitting the spot), please let us know at firstname.lastname@example.org so we can modify the thresholds for you.