title: Can a Bayesian network detect spam without spam training set
body: <p>Hi I have a conceptual question on a system I'm trying to develop that tries to classify emails. I have a large set (>100k) messages that are not spam and a large set of unclassified messages. Is it then possible to use a method (perhaps Bayesian) to detect spam without having a data set of spam? Do I absolutely need to classify spam?</p>