Tumbleweed Granted Patent for E-mail Firewall

Redwood City, CA – August 20, 2003 – Tumbleweed® Communications Corp. (NASDAQ:TMWD), a leading provider of mission-critical Internet communications software for enterprises, financial services organizations and government, announced today that it has been granted U.S. Patent No. 6,609,196 by the U.S. Patent and Trademark Office, titled “E-mail Firewall with Stored Key Encryption/Decryption.”

“The e-mail firewall has become a critical component of the network,” said Jeffrey C. Smith, Chairman and CEO, Tumbleweed. “Tumbleweed pioneered the market for e-mail firewalls, and now the U.S. Patent and Trademark Office has affirmed our position in this growing market by granting us the first e-mail firewall patent.”

Tumbleweed shipped its first implementation of an e-mail firewall in the same year the patent was filed, 1997. Tumbleweed’s e-mail firewall, Tumbleweed MMSâ„? (Messaging Management System), has been purchased and successfully deployed by hundreds of large enterprise customers and government agencies. In the second quarter of 2003, Tumbleweed shipped a new appliance implementation of the popular e-mail firewall software bundled with an update service for automating spam defense. Over 70 enterprise customers including 9 of the Fortune 500 purchased the Tumbleweed Dynamic Anti-spam Serviceâ„? in the first two months of availability.

Businesses and government agencies are realizing that the most effective defense against such network threats as spam and viruses is an e-mail firewall running at the perimeter of an enterprise network. Moreover, in addition to blocking network threats such as spam, an e-mail firewall can also effectively integrate policies to protect privacy and intellectual property, automate encryption and decryption capabilities, reduce liabilities associated with e-mail usage, and enhance regulatory compliance for areas such as HIPAA, GLB, and SEC. The e-mail firewall addresses these various issues cost-effectively, deployed as a single platform on the network, implemented either as software or as an appliance.

“Our e-mail firewall patent, U.S. Patent No. 6,609,196, is one of the more significant patents we’ve been granted to date,” said Bernard J. “Barney” Cassidy, General Counsel of Tumbleweed. “To date, ten companies have licensed our patents, and we plan to continue to enforce our patents when appropriate to protect our intellectual property.”

Originally submitted in 1997, the patent describes e-mail management and security components that may be integrated into one solution, including:
· an SMTP relay for sending/receiving e-mail
· a set of policy managers for enforcing administrator selectable policies
· an optional message encryptor
· an optional message decryptor

Policy managers are used to control inbound and outbound message traffic, including restricting outbound traffic, blocking inbound traffic, and rerouting traffic based on message source, destination, content, virus analysis, and/or the presence of digitally signed content.

“Between spam, viruses, liability management, and compliance, e-mail hygiene has become an area of focus for the enterprise,” said Matt Cain, analyst at Meta Group. “The e-mail firewall, which in effect combines these functions into a single solution running on the network, has emerged as the platform of choice to address these requirements. Tumbleweed’s new patent therefore could be interpreted as a significant event in the e-mail hygiene management market.”

Tumbleweed’s patent portfolio includes 13 granted U.S. patents and 20 pending U.S. patent applications in addition to another 60 pending worldwide. The patent portfolio broadly covers secure communication over Internet standards, including such areas as e-mail firewall implementation, the binding of content to electronic identity, and the delegation of encryption authentication to the server.

About Tumbleweed’s MMS e-Mail Firewall:
The Tumbleweed MMSâ„? e-mail firewall is rated by Information Security Magazine as the #1 e-mail firewall software for large enterprises, and is currently in use at over 400 of the largest, most demanding messaging infrastructures in the world. Tumbleweed MMS is an enterprise-class e-mail firewall for protecting, filtering and securing e-mail traffic at the Internet gateway. MMS manages the organization’s mission-critical e-mail stream with an integrated set of anti-spam, anti-virus, anti-hacker, content filtering, e-mail relay, and encrypted messaging capabilities – minimizing e-mail communications risks and reducing e-mail management costs.

Organizations use MMS to protect their networks from hacker, virus and spam threats; comply with e-mail regulations (SEC, NASD, HIPAA, GLB, FDA); enforce e-mail communications and security policies; and securely communicate with customers, partners and suppliers. Tumbleweed MMS complements and works seamlessly with corporate e-mail servers such as Microsoft Exchange, Lotus Notes, Novell Groupwise and a variety of UNIX-based e-mail servers. The product is available as both a software package for larger companies, or as an appliance that provides enterprise level protection and management capabilities to small and mid-sized companies.

About Tumbleweed Communications:
Tumbleweed is a leading provider of mission-critical Internet communications software products for enterprises, financial services organizations and government. By making Internet communications secure, reliable and automated, Tumbleweed’s email firewall, secure file transfer, secure email, and identity validation solutions help customers significantly reduce the cost of doing business. Tumbleweed products are used millions of end-users and tens of thousands of corporations. Tumbleweed customers include ABN Amro, Bank of America Securities, Catholic Healthcare West, JP Morgan Chase & Co., The Regence Group (Blue Cross/Blue Shield), Society for Worldwide Interbank Financial Telecommunication (SWIFT), St. Luke’s Episcopal Healthcare System, the US Food and Drug Administration, and the US Navy and Marine Corps. Tumbleweed Communications was founded in 1993 and is headquartered in Redwood City, California. For additional information about Tumbleweed go to www.tumbleweed.com or call 650/216-2000.

SAFE HARBOR STATEMENT

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 industry practices, the characteristics, benefits, and effectiveness of Tumbleweed’s products and services, as well the market for such products and services. 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 Annual Report on Form 10-K filed June 4, 2003, and Quarterly Report on Form 10-Q filed August 14, 2003.

Tumbleweed assumes no obligation to update information contained in this press release, which represents the Company’s expectations only as of the date of this release and should not be viewed as a statement about the Company’s expectations after such date. Although this release may remain available on the Company’s website or elsewhere, its continued availability does not indicate that the Company is reaffirming or confirming any of the information contained herein.