Letterman is an effective anti-spam solution that combines pre-defined rules with customizable filter options that allow immediate filtering of spam out of the box, with the ability to customize the settings to match your personal email patterns. The program works with any POP3, Hotmail and Yahoo account, independent from your email program, so you don`t have to download messages first in order to filter them - spam is delete right on the server and never downloaded to your computer. Letterman offers a wide range of filtering options, including subject, sender, domain, country, foreign languages, and more. The built-in filters detected about 80% of spam during our test, and you can easily fin-tune them with a few clicks. Since Letterman works independently from your email program, you need to manage and delete spam before you download your messages, which adds an extra step to the mail checking process, but has the advantage of not downloading spam and potential viruses to your computer. Overall a very flexible, spam tool, however it requires constant fine tuning and interaction to keep your inbox spam free.