IronMail

"Dedicated security appliance that sits between the network firewall and mail servers, including Exchange, to protect against buffer overrun and denial-of-service attacks, virus (using the Sophos anti-virus product), and spam. Monitors for other suspicious activities that might indicate an intrusion. Provides some e-mail policies for incoming and outgoing messages. Uses a hardware accelerator for SSL encryption, without the need to encrypt on every mail server. From Ciphertrust http://www.bi101.com/products/solutions/ironmail/index.php?cpe=Y3A9SXJvbk1haWwgU2xpcHN0aWNrJnM9SXJvbk1haWwgU2xpcHN0aWNrJmM9MQ%3D%3D CONTENT"