Microsoft's next major messaging client release, Microsoft Office Outlook 2003, will include exciting new security enhancements, including a pervasive antispam solution, that might make this release a compelling upgrade. Here's what you need to know about Outlook 2003's security and anti-junk email enhancements.

Weeding Out Unwanted Email
Microsoft first rolled out the new Outlook junk-email filter, which evolved from Microsoft Research technology, for MSN 8 customers last year. To access the filter, select Tools, Options, then click Junk E-mail. As Figure 1 shows, you can choose from among four levels of protection: No Protection, which turns off automatic junk email filtering; Low, which moves the most obvious junk email to a new Junk E-mail folder; High, which captures most junk email but also captures some regular email; and Trusted Lists Only, the most restrictive option, which directs Outlook to permit email only from senders or domains on your Trusted Senders list. You can also choose whether to automatically delete suspected junk email or to have Outlook move it to the Junk E-mail folder.

Microsoft's junk email-filtering feature appears to be similar to the Bayesian techniques that other messaging clients employ. These techniques have proven to be highly successful in filtering out unwanted email because they analyze the content of the messages instead of simply performing word matches.

Making Outlook More Secure
In addition to spam filtering, Outlook also supports a new and much needed change to the way it displays HTML email—it doesn't. Unlike earlier versions, Outlook 2003 by default doesn't display images in HTML email because these images, which are often stored on remote Web servers, can help junk-email senders identify valid email addresses. Such images load from the external server when you open the message, letting the sender know that your address is good. Microsoft says that if the images don't load by default, you're protected. Outlook gives you the option to load images that you believe are safe.

Recommendations
Outlook 2003 is a big upgrade over earlier versions for a variety of reasons, but I expect the antispam features in particular will drive many upgrades. Enterprises that are rolling out Exchange Server 2003 can use the new Microsoft Outlook Web Access (OWA) version, which also includes junk-email filtering, as an interim step. But I highly recommend Outlook 2003 for users accessing earlier Exchange versions or other types of email servers. The rest of Office 2003 might ultimately prove to be somewhat lackluster, but Outlook 2003 is a clear winner.