Interface Improvements In tests of Exchange Server 2003 Beta 2, we used both the Microsoft Outlook Web access client and the current beta release of Outlook 11 (which is part of the Office 11 suite). We liked the layout of both client interfaces, which were easier to navigate than Exchange 2000s interface.As many current users would attest, Outlooks sluggish performance on lower-speed and congested network links was definitely one of the more frustrating aspects of using Exchange 2000. However, the combination of Exchange Server 2003 and the new Outlook 11 client should make this experience less painful, thanks to Exchanges improved local caching system and the inclusion of automatic file compression capabilities.By reducing the number of remote procedure calls between the client and the server, Microsoft is trying to bring dial-up clients performance and usability up to more tolerable levels. We hope to confirm the better performance claims when gold code becomes available. To further bolster security, Outlooks new Web access client includes an attachment-blocking option and a session inactivity timeout (see Labs-Eye View). S/MIME (Secure Multipurpose Internet Mail Extension) support is now available for Outlooks Web access client (Exchange 2000s Web access client did not support it), which will allow users to encrypt or digitally sign mail messages. However, we would caution that its not a good idea for IT departments to implement S/MIME without having a firm grasp of Windows public-key infrastructure. Exchange Server 2003, like Windows .Net Server, ships with default security measures in place that should make servers less susceptible to vulnerabilities out of the box. (Exchange Server 2000s default security setting made it relatively easy to hack.) Exchange can run on Windows 2000 servers or Windows .Net Server 2003. For our tests, we installed the Exchange beta on Windows .Net Server 2003 Release Candidate 2. (See eWeek Labs Dec. 23/30 review of .Net Server 2003 RC2.) With Windows .Net Server 2003, Exchange will be able to scale to eight-node clusters. With the kernel improvements being made to Windows .Net Server 2003, Exchange Server 2003 is expected to be more efficient than Exchange 2000, which relies on the Windows 2000 kernel. Senior Analyst Henry Baltazar can be contacted at email@example.com.