MailFrontier Desktop is a comprehensive anti-spam solution that integrates with Microsoft Outlook and automatically filters incoming spam into a special junkmail folder. The software combines several popular spam filtering techniques as well as anti-phishing features. It uses Bayesian filtering to automatically learn from spam messages, and a combination of blacklists and allowed senders to permanently block or allow certain recipients. In addition, MailFrontier also includes a challenge system that enables you to require a verification from the sender before his or her mail is accepted. Other features include detailed spam statistics, forwarding of messages to wireless devices, customizable content filter settings and more. MailFrontier Desktop delivers very accurate filtering straight out of the box, and can be easily tweaked to adapt to your personal email preferences.

The license of this software is Free Trial Software, the price is $29.95, you can free download and get a free trial.