Tumbleweed Announces Availability Of Anti-Spam Quarantine Manager To Eliminate False Positives

Redwood City, CA – March 10, 2004 – TumbleweedR Communications Corp. (NASDAQ:TMWD), a leading provider of secure Internet messaging software for enterprises, financial services organizations and government, announced today the release of the Tumbleweed Personal Quarantine ManagerT, enabling enterprises to ensure that their employees never lose a business-critical email message. The Personal Quarantine Manager works with Tumbleweed’s Email Firewall, which provides highly effective spam blocking at the gateway. The Personal Quarantine Manager sends out a periodic HTML or text-based email to end users with a listing of all the email messages that have been blocked as suspected spam. To retrieve a blocked message, the end user merely clicks the “Release” button next to the email and it is delivered normally to his/her mailbox.

“Users need to be reassured that good email has not been identified as a false positive and quarantined,” said Maurene Caplan Grey, Research Director for Gartner. “Increasingly, a digest capability that lists mailbox-specific quarantined messages and allows users to retrieve them is emerging as a must-have customer requirement, and one of the key management features we look for in leading anti-spam vendors.”

Tumbleweed’s Email Firewall continues to deliver anti-spam capture rates up to 99% with false positive rates below 0.1%. The new Personal Quarantine Manager feature allows email administrators who manage a centralized spam quarantine queue to give end-users access to their quarantined spam on a “self-service” basis, thus reducing administrative and help desk costs, which lowers the Total Cost of Ownership (TCO) of the anti-spam solution. This capability is particularly useful to large organizations, where even very low rates of quarantined email traffic result in tens of thousands of messages in a quarantine queue.

“We are very happy with Tumbleweed’s email firewall and the job it does with spam,” said Vahik Gharibian, IT Infrastructure Manager for the William Morris Agency. “In addition, we love the fact that we can give our users access to the quarantined mail and let them decide what to do with it.”

Utilizing Tumbleweed’s patented email notification technology, the Personal Quarantine Manager sends out a periodic HTML or text-based email to end users with a listing of all the email messages that have been quarantined as suspected spam. In order to retrieve a message, the end user merely clicks the “Release” button or link next to the email, and it is delivered normally to the end user’s mailbox. End users may request an updated list of quarantined email at any time by simply clicking a button on the notification email. The Personal Quarantine Manager is currently a no-cost optional feature of Tumbleweed’s anti-spam solution, so email administrators can turn it on and off, and set the frequency that notifications are sent out.

Because the Personal Quarantine Manager uses a simple email to let the end user know about quarantined spam, it does not require desktop client software, end user training, or user authentication/password management. And because the Personal Quarantine Manager uses the proven security of Tumbleweed’s patented private URL technology for email notifications, there is little risk that user’s or hackers will be able to view someone else’s quarantined email.

“Tumbleweed understands that enterprises hate spam, but can’t afford to lose email messages, particularly from their customers and business partners,” said Dave Jevans, SVP of Tumbleweed Communications. “Over the past 7 years, Tumbleweed has delivered anti-spam and email security products that allow business partners to communicate securely with each other using email. This release of the Personal Quarantine Manager continues that focus on enabling our customers to ensure that their business messages are delivered and received reliably, without spam.”

About the 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.

About Tumbleweed Communications Corp.
Tumbleweed is a leading provider of secure Internet messaging software products for enterprises, financial services organizations and government. By making Internet communications secure, reliable and automated, Tumbleweed’s email firewall, secure file transfer, secure email, and identity validation solutions help customers significantly reduce the cost of doing business. Tumbleweed products are used by millions of end-users and tens of thousands of corporations. Tumbleweed customers include ABN Amro, Bank of America Securities, Catholic Healthcare West, JP Morgan Chase & Co., The Regence Group (Blue Cross/Blue Shield), Society for Worldwide Interbank Financial Telecommunication (SWIFT), 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, Calif. 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 sales from Tumbleweed’s anti-spam solution and the potential growth of the anti-spam market, . 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 June 4, 2003, Form 10-Q filed November 14, 2003, and Form S-3/A filed December 19, 2003.

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.