Tumbleweed Allowed Patent for Server-to-Server Encryption and Data Conversion

New allowance the fifth patent for Tumbleweed

REDWOOD CITY, CA - July 19, 2000 - Tumbleweed® Communications Corp. (Nasdaq:TMWD), a leading provider of advanced email solutions for business communications, today announced that Tumbleweed has been allowed a patent that provides for server to server encryption coupled with data conversion.

The new patent covers server to server secure encryption using technologies such as public key infrastructure (PKI). The patent also covers data conversion. Combined, these technologies enable business partners to automatically and securely exchange confidential information that can be read in whatever format a recipient normally uses. The patent provides for data to be encrypted and transmitted in a format such as XML and then decrypted and dynamically converted into an easy to read format such as HTML before reaching the recipient's desktop.

"With mission critical businesses processes like supply chain management moving rapidly online, server to server encryption coupled with data conversion is a vital solution," said Jean-Christophe Bandini, chief technology officer, Tumbleweed Communications Corp. "Tumbleweed has established a depth of protected intellectual property in secure messaging that provides an excellent foundation for the products our customers use as well as for our position in the markets we serve."

Tumbleweed's products include Tumbleweed Integrated Messaging Exchange™ (IME™) a platform and set of applications for creating secure communications channels between a business and its customers, partners, and suppliers; and Tumbleweed Messaging Management System, (MMS™) a set of email management products and services that enables enterprises to protect valuable corporate information on the Internet.

In addition to this newly allowed patent, Tumbleweed has also been allowed a patent for Tumbleweed. Dynamic Server-Based Data Conversion [see press release dated April 26, 2000 at www.tumbleweed.com]. Tumbleweed has also been granted three patents. Patent #: 6,061,448 "Method and System for Dynamic Server Document Encryption" was granted May 9, 2000. Patent #: 399,836 "Electronic Document Delivery System" was granted October 20, 1998. Patent #: 5,790,790 "Electronic Document Delivery System in which Notification of Said Electronic Document is Sent to a Recipient Thereof" was granted August 4, 1998.

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.