Microsoft's Offerings
Microsoft has put a great deal of emphasis on beefing up the security of its products by improving design, development, testing, and support. This effort has already borne fruit (just compare Secunia's reported vulnerability counts for Windows Server 2003 and Windows 2000), and Microsoft is helping speed up the rate of improvement by adding security-focused products and features to its existing portfolio.
On the antivirus front, Microsoft bought GECAD Group (a Romanian software company little known in the United States but internationally recognized as a successful antivirus solutions provider) and antivirus company Sybari Software. Microsoft has since announced its Client Protection product for desktops and has renamed Sybari's Antigen to Microsoft Antigen—probably as a harbinger of future server-based security products.
In the antispam world, Microsoft offers an extensive set of spam filtering features in Outlook 2003 and Exchange Server 2003. The combination of Outlook 2003 and the Exchange Intelligent Message Filter (IMF) provides excellent filtering based on a large corpus of spam gathered through MSN Hotmail. That makes this combination of client and server-side filtering a good fit for many small organizations because there's no additional cost over the product licenses. However, neither the Outlook nor Exchange filtering system is very flexible, and the update frequency has slowed since the products were released. If you want more control over the filtering process, you'll have to use another solution.
Choose Wisely
Small businesses might not have the numbers of workstations that larger companies do, but they face the same threats from viruses and spam. Designing a multilayered defense requires carefully choosing products that match the requirements of your environment. The resulting layers of security create effective protection.
Paul Robichaux (troubleshooter@ robichaux.net) is a principal engineer for 3sharp, an MCSE, and an Exchange MVP. He is the author of several books, including The Exchange Server Cookbook (O'Reilly and Associates), and creator of the http://www.exchangefaq.org Web site.