Proofpoint, Inc., a provider of unified email security, archiving, and data loss prevention solutions, announced the availability of Proofpoint Shield, an enterprise email security solution. Proofpoint Shield, a SaaS (Software-as-a-Service) solution, defends against malicious and spam email connections, reduces inbound spam volume, and prevents denial-of-service and directory harvest attacks. The new solution can be deployed in front of any on-premises secure email gateway appliance including the Proofpoint Messaging Security Gateway as well as third-party solutions from Cisco (IronPort), McAfee (Secure Computing/CipherTrust), Symantec, Trend Micro, and Tumbleweed. Proofpoint Shield uses Proofpoint Dynamic Reputation and netMLX technology to make intelligent decisions about whether to accept, throttle, or reject incoming email connections. Accepted messages and their attachments are then scanned for spam characteristics, using a version of the Proofpoint MLX anti-spam engine, which examines structural and content attributes to accurately reject spam messages. The remaining messages are delivered to the customer’s on-premises email security gateway, which can apply additional anti-spam and anti-virus scanning, policy enforcement, email routing, and other MTA features.