Ninja Email Security Appliance from Sunbelt Software is almost like an email security plugin for Microsoft Exchange servers. It takes an all-in-one security approach with features such as anti-spam, anti-phishing, anti-virus, attachment filtering, disclaimers and content filtering. The Ninja uses proprietary anti-spam technology, along with Cloudmark, as well as anti-virus from Authentium and BitDefender. Finally, this product also uses a proprietary content filter to manage suspicious attachments.