Sunbelt Software's Sunbelt Messaging Ninja offers spam, virus, and attachment filtering for Microsoft Exchange 2000 Server and later. Ninja's policy-based approach lets you create different rules for users and groups and enforce policies according to destination, source, and direction (e.g., incoming, outgoing).
Ninja uses Authentium and BitDefender antivirus engines and Cloudmark's signature-based spam filter as well as Sunbelt's own heuristic engine. Ninja also supports Realtime Blackhole Lists and Sender Policy Framework. The product runs on your Exchange servers and has the unique ability to scan internal email. The trade-off, however, is that Ninja uses processor resources and can increase the server load by up to 20 percent.
Installation is a 20-minute process that requires restarting the Exchange service. You control Ninja through Microsoft Management Console (MMC). Managing multiple servers requires opening multiple MMC instances, which might be a hassle for multiple-site organizations.
Comparable solutions offer similar functionality at a lower price. Because they typically run on the gateway, however, such products can't filter internal email or provide Ninja's granular configuration options.
PROS: Lets you set different rules for groups and individual users;
dual antispam and antivirus engines; filters by message source and destination
- Joel B. Barker