U.S. Patent & Trademark Office Grants Tumbleweed New Message Filtering Patent

Redwood City, Calif. – Sept. 11, 2007 – Tumbleweed® Communications Corp. (NASDAQ:TMWD), an industry leader in managed file transfer and content security, today announced that it has been granted U.S. Patent No. 7,257,564 by the U.S. Patent and Trademark Office.

The new patent, titled "Dynamic Message Filtering," describes a method and system of dynamically filtering incoming messages into one of three categories: good, bulk, or spam. 

Tumbleweed's patent portfolio includes 27 granted U.S. utility patents. The patent portfolio broadly covers secure communication over Internet standards.

SAFE HARBOR STATEMENT
Tumbleweed cautions that forward-looking statements contained in this press release are based on plans and expectations as of the date of the 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 development and enforcement of Tumbleweed’s patent portfolio. 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 14, 2007 and Form 10-Q filed August 7, 2007.
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 Tumbleweed
Tumbleweed Communications Corp. (NASDAQ:TMWD), the industry’s leading pure play messaging security vendor, provides world-class innovative messaging security solutions for organizations of all sizes.  Organizations rely on Tumbleweed's solutions to securely manage their Internet communications, spanning email management to file transfers. Tumbleweed has more than 2,900 customers worldwide, representing industries such as Finance, Healthcare, and the U.S. Government. The world’s most security conscious organizations rely upon Tumbleweed technology including Bank of America Securities, JP Morgan Chase & Co., the U.S. Food and Drug Administration, and the U.S. Department of Defense. Our award-winning products build on fourteen years of R&D and 27 security patents in the U.S. alone – many of which are licensed by other security vendors. More information can be found at www.tumbleweed.com.
Tumbleweed is a registered trademark of Tumbleweed Communications Corp. in the United States and/or other countries.  All other trademarks are the property their respective owners.

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