Tumbleweed Allowed Patent for Dynamic Server-Based Data Conversion

Secure communications channel facilitates rapid delivery of account information

REDWOOD CITY, CA - April 26, 2000 - Tumbleweed® Communications Corp. (Nasdaq:TMWD), a leading provider of Internet communications services, today announced that the U.S. Patent and Trademark Office has allowed Tumbleweed a patent for dynamic server-based data conversion.

Tumbleweed Integrated Messaging Exchange™ (IME™) enables secure online delivery of information to any recipient with an email client and a browser. The data conversion technology that Tumbleweed developed enables the automatic conversion of information sent via IME into the appropriate format for delivery and viewing. The format - such as Wireless Access Protocol (WAP), Hypertext Markup Language (HTML) or Graphic Interchange Format (GIF) - is dynamically selected based on information on format capabilities and preferences that can be stored in a database or a Lightweight Directory Access Protocol (LDAP) directory.

"This is the fourth Tumbleweed patent that covers innovations in our IME platform. Via the dynamic data conversion included in the IME platform, companies can automatically send important information to their customers on the machines their customers use most. This is an essential element in extending online messaging to wireless devices," said Jeffrey C. Smith, president and CEO of Tumbleweed Communications Corp. "The dynamic format conversion removes the complexity inherent in delivering messages like bills and statements in a format each recipient can easily recognize."

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.