our customizable newsletter, sends you security alerts, product updates and software patches on the products you use. Sign up now at www.networkcomputing.com /express/

I tested a beta version of NAV for Exchange in Network Computing's San Mateo, Calif., lab. During testing, it successfully detected viruses, repaired infected files and, most important, stopped viral transmission.

Missing Links NAV Exchange runs as an NT service and supports Microsoft Exchange 4.0 or later, as well as NT Server 3.51 or later. In the lab, I configured Exchange to receive e-mail from native Exchange, POP3, IMAP and Web clients. My test bed included a Hewlett-Packard Co. E50 server with 256 MB of RAM and a 4-GB Ultra SCSI hard disk running Microsoft NT Server 4.0 with Service Pack 3.

NAV for Exchange installs its own HTTP server that is configurable to run on any IP port. It does not support SSL (Secure Sockets Layer) encryption, nor can it use any other HTTP server. The server provides two methods of access control: password and subnet restrictions. However, during testing, I found it time-consuming to have to go into the NT registry to modify the lists of subnets that can access the server. Symantec should address this problem in the next version, as it hinders the product's HTML management interface's ease of use.

The interface worked well with my Netscape Communicator 4.03 and Microsoft Internet Explorer 4.0 and 4.01 Web browsers. Alternatively, you can use the Norton System Center, a separate product that lets you administer the server. The HTML interface's functionality is somewhat limited and lacks context-sensitive help buttons.

NAV for Exchange cannot perform the same operation across all servers or a subset of Exchange servers. If a new virus is found on your network and you need to issue an immediate scan of all the servers in your enterprise, you must visit each server individually--an arduous task if your enterprise includes 40 or more servers. Letting the administrator initiate a manual scan on all Exchange servers simultaneously would be a better solution.

NAV for Exchange could be further improved with the addition of granular administration, which lets a particular user check on system status and run manual scans, while an administrator changes the configuration options. The list of users should integrate with the Exchange user ID list or with an NT domain. Unfortunately, in the current version, once a user has gained access to the administrator console via a common password, he or she can perform any tasks.

Warding Off Viruses To control macro viruses, NAV for Exchange uses MVP technology. Although I did not test this feature, Symantec claims that MVP prevents the distribution of macros that are not on an approved list. This list is a .DAT file that you can configure via a utility on the company's Solutions CD, available to those with Platinum User Support.

NAV for Exchange incorporates 14 different virus-detection engines. Besides MVP, Bloodhound, a heuristic scanning engine, looks at file properties and applies a rule-based system to determine if the file is infected. Striker technology detects polymorphic viruses by creating a virtual environment and evaluating the program logic, instructions and data.

NAV for Exchange can scan compressed files, and it supports the most common compression and encoding formats, such as ZIP, ARJ, MIME, UUENCODE and CAB. In the lab, I e-mailed ZIP, ARJ and ZIP-compressed ARJ files, and NAV detected all of them. Like other antivirus products, it can not scan encrypted files.

Besides real-time scanning, NAV for Exchange supports scheduled and on-demand scanning. I performed an entire scan on our server, including inboxes and public and private folders. The on-demand scanning lets the server administrator initiate a scan. This feature helped me find virus-infected files in public folders.

Of course, your virus scanner is only as good as it is current--new viruses and variants of old viruses appear every day. To facilitate the process of updating virus signature files, NAV features LiveUpdate, which updates the signature files automatically or on demand. This tool saved me a lot of time in the lab.

For NAV for Exchange to pass through a firewall to Symantec's Internet site, you need the Norton LiveUpdate administrator utility, which is available on the Solutions CD. This utility lets the system administrator configure LiveUpdate to pull the updates from an internal FTP server or shared server volume. Given Symantec's desire to be an enterprise player, this functionality should be included with the product.

NAV for Exchange costs about $30 per user; if your network hosts a large Exchange deployment, budget accordingly. It runs on only Intel-based systems, and Symantec currently has no plans to port it to Alpha-based servers.

Jay Milne is a networking consultant. Send your comments on this article to him at jmilne@gene.com.