MemorialCare Selects Tumbleweed MailGate Email Firewall to Combat Spam, Virus, Phishing and Other Email Attacks; Solution Blocking More Than 300,000 Spam Messages per Week and Supporting Over 5,000 Email Users.

REDWOOD CITY, Calif. -- Tumbleweed(R) Communications Corp. (NASDAQ:TMWD), a leading provider of e-mail security, file transfer security, and identity validation software and appliances, announced today that MemorialCare, one of Los Angeles and Orange County's leading health care systems, has chosen Tumbleweed MailGate(R) Email Firewall to block spam, viruses, phishing attacks and other email based threats.

Established in 1996, MemorialCare is the only Southern California healthcare system to have women's and children's rehabilitation hospitals located on one campus. The MemorialCare Health System (MHS) locations include the Anaheim Memorial Medical Center, Long Beach Memorial Medical Center, Miller Children's Hospital in Long Beach, Orange Coast Memorial Medical Center in Fountain Valley and Saddleback Memorial Medical Center in Laguna Hills. Protecting employees from inbound email threats has become a high-level priority at MemorialCare. To address their email security concerns, email administrators sought to implement an email security solution that would streamline communication throughout the organization and reduce costs.

Like many healthcare organizations today, MemorialCare has struggled to protect its email network against a consistently growing flow of spam, viruses, Denial of Service (DoS) attacks and other email threats. With an increase of these types of threats, employees of MemorialCare were experiencing lost hours of productivity and email network administrators were spending significant amounts of time and resources trying to control the influx of spam and other email threats. MemorialCare addressed their growing email security concerns by implementing MailGate Email Firewall(TM) to protect, filter and secure email traffic throughout the organization's network. With the use of MailGate Email Firewall, more than 5,000 MemorialCare email users are protected against a multitude of inbound email threats. MailGate Email Firewall correctly identifies and blocks the 75 percent of incoming email messages that are spam with virtually no false positives.

"The growing volume of spam, as well as the potential privacy damage that could come from errant email content, made it a necessity for us to implement an anti-spam solution. MailGate Email Firewall provides us with a single point for email hygiene, including spam blocking, virus protection and content filtering of inbound emails," said Penny Dobb, Executive Director of Shared Services for Memorial Health Services.

In addition, MailGate Email Firewall is increasing MemorialCare's user productivity by blocking spam before reaching the mail servers and inboxes and causing internal disruptions. As a result, end-users are much more productive without the burden of spam, and MemorialCare is able to lighten network loads and free up resources throughout their messaging network. MailGate Email Firewall scans over 300,000 inbound emails per week, or over 15.6 million a year for MemorialCare email users. Email administrators can now also monitor and control the MailGate Email Firewall, while Tumbleweed's anti-spam service constantly updates spam definitions to free-up IT resources.

"The sharing of sensitive information through email has become a necessity in today's healthcare industry, however some organizations do not recognize the need and importance of securing those emails until it's too late," said Willy Leichter, Director, Product Marketing - Email Security at Tumbleweed. "Through the use of MailGate Email Firewall, MemorialCare can proactively ensure their emails networks are secure, safe and protected against threats."

Safe Harbor Statement

Tumbleweed cautions that forward-looking statements contained in this press release are based on current plans and expectations as of the date of this press release, and that a number of factors could cause the actual results to differ materially from the guidance given at this time. These factors are described in the Safe Harbor statement below.

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 performance and functionality of Tumbleweed's products. 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 16, 2005 and Form 10-Q filed November 2, 2005.

Tumbleweed assumes no obligation to update information contained in this press release. Although this release may remain available on Tumbleweed's website or elsewhere, its continued availability does not indicate that Tumbleweed is reaffirming or confirming any of the information contained herein.

About MemorialCare

In 1996, the five Memorial Health Services Medical Centers set out to create an organization dedicated to quality health care. The new organization, called MemorialCare, has become one of Los Angeles and Orange County's leading health care systems. Its medical centers include Anaheim Memorial Medical Center, Long Beach Memorial Medical Center, Miller Children's Hospital in Long Beach, Orange Coast Memorial Medical Center in Fountain Valley, Saddleback Memorial Medical Center in Laguna Hills and Saddleback Memorial Medical Center in San Clemente. MemorialCare is the only Southern California health care system to have rehabilitation, women's and children's hospitals located on one campus.

About Tumbleweed Communications Corp.

Tumbleweed provides security solutions for email protection, file transfers, and identity validation that allow organizations to safely conduct business over the Internet. Tumbleweed offers these solutions in three comprehensive product suites: MailGate, SecureTransport(TM), and Validation Authority(TM). MailGate provides protection against spam, viruses, and attacks, and enables policy-based message filtering, encryption, and routing. SecureTransport enables business to safely exchange large files and transactions without proprietary software. Validation Authority is the world-leading solution for determining the validity of digital certificates. Tumbleweed's enterprise and government customers include ABN Amro, Bank of America Securities, Catholic Healthcare West, JP Morgan Chase & Co., The Regence Group (Blue Cross/Blue Shield), St. Luke's Episcopal Healthcare System, the U.S. Food and Drug Administration, the U.S. Department of Defense, and all four branches of the U.S. Armed Forces. Tumbleweed was founded in 1993 and is headquartered in Redwood City, Calif. For additional information about Tumbleweed go to www.tumbleweed.com or call 650-216-2000.

Tumbleweed, the Arrows logo, MailGate, MailGate Email Firewall, SecureTransport and Validation Authority are either registered trademarks or trademarks of Tumbleweed Communications Corp. in the United States and/or other countries. All other trademarks are the property of their respective owners.