Besides planning for anti-spam, you need also to consider protecting your Exchange organization from viruses or other dangerous software applications.
Exchange Server 2010 Antivirus Protection
E-mail is one of the most common ways to spread viruses from one organization to another. The security community even refers to email as a vector used to spread viruses. One of the primary tasks in protecting your Exchange Server organization is to ensure that all messages containing viruses are stopped at the messaging environment's perimeter.
Although Exchange Server 2010 already provides some basic antivirus features, it is important to implement a separate antivirus product based on VSAPI that supports Exchange 2010.
Exchange Server ...