Ask HN: Spam Filters
2 comments
Gmail is likely using a Bayesian classifier for spam detection. So, it adds the characteristics of the spam to the spam filters, not the message itself.
http://www.paulgraham.com/spam.html
http://www.paulgraham.com/spam.html
I don't know what gmail does, but what you describe can be done with spamassassin. The Horde webmail program has a way for users to submit false positives and false negatives to the spamassassin training command.
Looking around, it seems like spam filters are trained using only certain trusted users. Does this functionality already exist?