What are some alternatives?
Spam Reader - Spam Reader is a free anti-spam add-on for Microsoft Outlook.
Spamfence.net - Professional e-mail security free for private use: With Spamfence.
SpamSieve - Save time by adding powerful spam filtering to the e-mail client on your Mac.
SpamAssassin - Use this program to "Unspam" your mailbox(es).
POPFile - POPFile classifies email into categories you define.
Scrollout F1 - Scrollout is a free and easy to use anti-spam email gateway designed for Linux & Windows administrators without advanced email security experience.