Graybar Deploys Tumbleweed's Anti-Spam Update Service to Stop 99% of Spam.

Business Editors/High-Tech Writers

REDWOOD CITY, Calif.--(BUSINESS WIRE)--March 30, 2004

Automated Update Service Reduces Spam Administration Requirements

By More Than 90%, Freeing Up Over 40 Hours Per Week

Tumbleweed(R) Communications Corp. (Nasdaq:TMWD), a leading provider of secure Internet messaging software and appliances for enterprises and government agencies, announced today that Graybar, North America's leading electrical and telecommunications distributor, has selected and deployed Tumbleweed's Dynamic Anti-spam Service(TM) to combat spam. This automated anti-spam update service, which runs on top of the Tumbleweed Email Firewall, is now automatically identifying and blocking 99% of Graybar's inbound spam email with little to no administration required.

Graybar, an employee-owned Fortune 500 corporation, is a leader in the distribution of high-quality electrical and telecommunications products and an expert provider of related supply chain management and logistics services. Graybar recently was awarded a 2003 InfoWorld 100 award in recognition of outstanding technology leadership for its Enterprise Resource Planning (ERP) system and named for the first time to the annual InformationWeek 500. The company has 6,000 active email users spread across 250 U.S. locations, who receive approximately 120,000 emails daily, over 75% of it considered spam. The IT organization tracks the amount of email entering the company and found that the amount of spam was rising at an alarming rate.

Graybar has been using the Tumbleweed Email Firewall for over three years to filter inbound and outbound email for potentially harmful viruses, mass mail worms, inappropriate content, executable file attachments, and spam. However, Graybar's IT organization knew that the exponential growth of inbound spam over the past year would soon become a major problem. Managing whitelists and blocklists required increasing amounts of administrative overhead, and was decreasing in effectiveness as spammer tactics such as address and identity spoofing continued to evolve. After learning about Tumbleweed's Dynamic Anti-spam Service, an automated anti-spam update service that works with Tumbleweed's Email Firewall. Graybar tested the spam service. The system proved to be so effective that they quickly put it into production. Once implemented, Tumbleweed's Dynamic Anti-spam Service was able to trap 99% of spam with no false positives. Because of the automatic nature of Tumbleweed's spam service, Graybar was able to reduce significantly the administrative time spent battling spam.

"We've been working with Tumbleweed for 3 1/2 years now, starting with anti-virus and content filtering capabilities, and now anti-spam," said Ted Hoffman, Director Enterprise Architecture and Operations at Graybar. "We continue to do business with Tumbleweed because they have a mature email firewall products, with broad functionality, and have proven to be best-in-breed across the board. Going forward, we are investigating ways to use Tumbleweed's products to further enhance management of the email environment."

About Tumbleweed's Email Firewall

Tumbleweed Email Firewall has been recognized as the #1 enterprise software solution for fighting spam according to Network World (http://www.nwfusion.com/reviews/2003/0915spam.html), and the #1 email firewall software for large enterprises by Information Security Magazine. Tumbleweed Email Firewall protects, filters and secures email traffic at the Internet gateway with an integrated set of anti-spam, anti-virus, anti-hacker, content filtering, email relay, and encrypted messaging capabilities -- minimizing email communications risks and reducing email management costs. Tumbleweed Email Firewall is used by over 400 of the largest, most demanding messaging infrastructures in the world, and is available in both appliance and software editions.

About Tumbleweed's Dynamic Anti-Spam Service

The Tumbleweed Dynamic Anti-Spam Service (DAS) is rated as the top anti-spam software and appliance for large enterprises by Network World magazine, and the product is currently used to block over 32 million spam messages per day on behalf of our customers. DAS is an Internet-based subscription service that updates the Tumbleweed email firewall with new heuristic defenses as they are published, similar to the way anti-virus engines work. The email firewall includes a highly effective Spam Analysis Engine, which automates the identification of spam using powerful heuristics-based analysis technology; typical customers see an immediate 90%+ capture rate with one-tenth of one percent false positive rate before tuning. Tumbleweed's Message Protection Lab develops and publishes the heuristic updates: the Lab is staffed by experts who continually analyze spam to identify new spammer trends and tactics, and create and publish new heuristics to stop them. The Lab analyzes both spam and legitimate email gathered internationally and provided by enterprise customers, to ensure that the Dynamic Anti-Spam Service minimizes false positives in a business environment.

"The combination of the Tumbleweed Email Firewall and Dynamic Anti-spam Service provides firms like Graybar with a multi-layer, automated approach to email hygiene and the fight against spam," said Dave Jevans, Senior Vice President of Marketing for Tumbleweed Communications.

About Graybar

Graybar, a Fortune 500 corporation and one of the largest employee-owned companies in North America, is a leader in the distribution of high quality electrical and telecommunications products, and an expert provider of related supply chain management and logistics services. Through its network of 250 North American distribution facilities, it stocks and sells products from thousands of manufacturers, serving as the vital link to hundreds of thousands of customers. For more information, visit www.graybar.com.

About Tumbleweed Communications Corp.

Tumbleweed is a leading provider of secure Internet messaging software and appliances for enterprises and government agencies. By making Internet communications secure, reliable and automated, Tumbleweed's anti-spam email firewall, secure file transfer, secure email, and identity validation solutions help customers significantly reduce the cost of doing business. Tumbleweed products are used to communicate with millions of end-users and tens of thousands of corporations. Tumbleweed has more than 600 enterprise customers, including ABN Amro, Bank of America Securities, Catholic Healthcare West, JP Morgan Chase & Co., The Regence Group (Blue Cross/Blue Shield), St. Luke's Episcopal Healthcare System, the US Food and Drug Administration, and the US Navy and Marine Corps. Tumbleweed Communications was founded in 1993 and is headquartered in Redwood City, California. For additional information about Tumbleweed go to www.tumbleweed.com or call 650-216-2000.

SAFE HARBOR STATEMENT

Tumbleweed cautions that forward-looking statements contained in this press release are based on current plans and expectations, and that a number of factors could cause the actual results to differ materially from the guidance given at this time. These factors are described in the Safe Harbor statement below.

Except for the historical information contained herein, the matters discussed in this press release may constitute forward-looking statements that involve risks and uncertainties that could cause actual results to differ materially from those projected, particularly with respect to the sales of Tumbleweed solutions and the efficacy of those solutions for particular users. In some cases, forward-looking statements can be identified by terminology such as "may," "will," "should," "potential," "continue," "expects," "anticipates," "intends," "plans," "believes," "estimates," and similar expressions. For further cautions about the risks of investing in Tumbleweed, we refer you to the documents Tumbleweed files from time to time with the Securities and Exchange Commission, particularly Tumbleweed's Form 10-K filed March 15, 2004.

Tumbleweed assumes no obligation to update information contained in this press release, including for example its guidance regarding its future performance, which represents the Company's expectations only as of the date of this release and should not be viewed as a statement about the Company's expectations after such date. Although this release may remain available on the Company's website or elsewhere, its continued availability does not indicate that the Company is reaffirming or confirming any of the information contained herein.