POPFile is an email classification system, that automatically sorts your messages and fights spam. It acts as a proxy between your email program and the mail server, scanning all incoming mail and then marks the mail according to your settings. When you first install the program, it is dumb and does not perform any classification at all - it is designed to learn from your personal classifications and becomes more and more hands-off the longer you use it. It keeps a history of all email messages that pass through the system and then allows you to classify each message as good, spam or any other criteria (personal, work, important etc.). These criteria are called "Buckets" and they are similar to virtual mail folders. The mail in each bucket will be tagged in a special way (subject, header), so you can instruct your email program to process it according to your preferences. POPFile does not delete any email on its own, however you can instruct your email program to act upon messages that are tagged as spam (or anything else) and have them be deleted or send to a different mail folder. The program offers an additional Quarantine option that can wrap the message in a container, allowing you to get an idea of the content, without actually opening any attachments or images of the original mail. POPfile uses Naive Bayes classification, which is highly effective an learns from your instructions. Overall, POPfile provides great flexibility and accurate filtering, however it does require at least some basic understanding of email and POP accounts in order to use it effectively.