What is the difference between K9 and POPFile?
POPFile is a general purpose email classification system written in the Perl scripting language. It was one of the first email classification systems to use Bayes theorem statistical analysis to determine how an email text message should be filtered based upon previous encounters with other email messages. Because POPFile is written in a scripting language it works on a number of different operating systems. The main interface to POPFile is through your web browser connected to POPFile’s built-in web server. K9 is also a Bayes theorem-based email classification program but it is specifically written to only differentiate between spam (junk) email and good email. It is written in C++ as a native Windows application and thus only works on Windows operating systems.