Diners Club Selects Tumbleweed Solution

Secure communications channel facilitates rapid delivery of account information

REDWOOD CITY, CA - July 18, 2000 - Tumbleweed® Communications Corp. (Nasdaq:TMWD), a leading provider of advanced email solutions for business communications, today announced that Diners Club International has chosen Tumbleweed Integrated Messaging Exchange™ (IME™) as its platform for secure online communications.

Tumbleweed IME is a platform and set of applications for creating secure communications channels between a business and its customers, partners, and suppliers. Diners Club will use IME to enable secure messaging between its corporate customers and employees.

"With the volume of confidential account management information we must manage to effectively service our customers, we required an efficient online communications channel that would provide immediate access to critical account information without sacrificing security and confidentiality," said Charles Kim, vice president, operations technology, Diners Club. "Tumbleweed IME delivers what we require. We conducted significant testing before making the commitment to Tumbleweed IME as our online communications platform."

"Diners Club is committed to the highest security standards, which reflects the quality of their commitment to their customer base," said Jeffrey C. Smith, president and CEO, Tumbleweed Communications Corp. "We are delighted that Diners Club has chosen to entrust its online communications to Tumbleweed IME."

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.