...always been one major problem associated with protecting an Exchange Server from viruses, and that is keeping the virusdefinition files up to date. Fortunately, Microsoft now offers a product called Microsoft ForeFront Security for Exchange...
http://articles.techrepublic.com.com/2415-22_11-190250.html
...been tested with and complements these solutions: Anti-virus. Maintaining and requiring the latest anti-virusdefinition files is crucial. Mobility XE’s NAC module interoperates with products from leading anti-virus vendors to ensure...
http://www.netmotionwireless.com/assets/netmotion_security.pdf