US District Court Clarifies Ruling and Requests Additional Briefing In Patent Infringement Case

REDWOOD CITY, CA - November 21, 2000 - Tumbleweed® Communications Corp. (Nasdaq:TMWD), a leading provider of secure Internet messaging services, today announced that the U.S. District Court in San Jose, California, has issued an order clarifying its earlier claims construction ruling in Tumbleweed vs. the docSpace Company (a wholly-owned subsidiary of Critical Path, Inc.).

The Court invited Tumbleweed to submit additional briefing to address the pending summary judgment motions on the issue of whether Critical Path technology infringes Tumbleweed's patent. Tumbleweed's brief is due on December 26, 2000. The new order does not resolve the summary judgment issues before the Court.

"Tumbleweed welcomes the opportunity to present further information to the Court in this case," said Bernard J. Cassidy, vice president and general counsel, Tumbleweed Communications Corp. "In addition, we have received a new patent allowance this year which we believe will both simplify the process for the Court and substantially enhance our infringement case. We remain confident that we will prevail on the merits of the case."

The Court's order came in the patent infringement suit brought by Tumbleweed against The docSpace Company Inc. on March 3, 1999.

About Tumbleweed Communications Corp.
Tumbleweed is a leading provider of solutions for managing secure communication and collaboration to enable the business Internet. Tumbleweed's robust policy-based framework empowers organizations to safely share and protect critical information, increase customer loyalty and privacy and dramatically reduce costs. Tumbleweed is trusted by 1,000 blue-chip customers including American Express, Chevron, Datek Online, the European Union's Joint Research Council, First Union Wachovia, John Deere, Merrill Lynch, Nike, Northern Trust, NTT, Salomon Smith Barney, Travelers and US Food and Drug Administration. One hundred of the Fortune 500 are Tumbleweed customers. Tumbleweed Communications was founded in 1993 and is headquartered in Redwood City, Calif., with offices around the world.

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 security features of Tumbleweed's products and the activities of any third party. 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 30, 2001 and Form 10-Q filed November 13, 2001. Tumbleweed assumes no obligation to update information contained in this press release.