Tumbleweed Granted Patent for Private URLs in Secure Document Delivery and Authentication

REDWOOD CITY, CA — February 21, 2001— Tumbleweed Communications Corp.. (NASDAQ: TMWD), a leading provider of mission critical messaging solutions, today announced that the U.S. Patent and Trademark Office granted the company patent no. 6,192,407, which protects private, trackable URLs for directed document delivery. The private URL technology is included in Tumbleweed Integrated Messaging ExchangeTM (IMETM), a platform and set of applications for creating secure communications channels between a business and its customers, partners, and suppliers.

Tumbleweed IME generates a private URL for each secure delivery. The private URL that IME creates is unique, tied to the sender of the package or transaction, to the content being sent, and to the intended recipient. In practice, the private URL binds the recipient’s e-mail identity to the content being sent, assuring that the information being sent is delivered only to the intended recipient. The private URL also binds a recipient’s e-mail identity to an on-line transaction, facilitating authentication for both business-to-consumer and business-to-business online commerce.

“This private URL patent protects the foundation of Tumbleweed’s secure communications products and technologies,” said Jean-Christophe Bandini, chief technology officer, Tumbleweed Communications Corp. “The private URL technology enables e-mail to play the central role in secure communications and commerce by binding a recipient’s identity to either content or a transaction.”

The patent application was filed in April 1997.

Tumbleweed Communications Corp.

Tumbleweed Communications (NASDAQ: TMWD) is a leading provider of mission critical messaging solutions that enable organizations to manage and secure online business communications and processes. Tumbleweed’s customers use the company’s solutions to define secure communication networks, to centrally control and monitor the corporate communications stream and to create a foundation for automated preparation and secure Internet delivery of sensitive business information. Companies that rely on Tumbleweed Communications solutions include American Express, Chase Manhattan Bank, Chevron, Datek Online, the European Union’s Joint Research Council, FDA, John Deere, Merrill Lynch, Nike, Northern Trust, NTT, Salomon Smith Barney, Travelers, United Parcel Service, and seven of the world’s largest postal services. Tumbleweed Communications was founded in 1993 and is headquartered in Redwood City, CA.