Castelle’s FaxPress Premier™ Fax Servers Have Been Approved By Fujitsu As an “Interstage Enabled” Product in Japan

FaxPress Premier and the Fujitsu Interstage Suite Offers Combined Document Fax Solution for Japan’s Enterprise Market

MORGAN HILL, CA – March 21, 2006 –  Castelle® (Nasdaq: CSTL), a leader in ‘all-in-one’ network fax solutions for the business and enterprise markets, today announced that FaxPress Premier™ has been approved by Fujitsu Limited (TSE:6702) as an “Interstage Enabled” product.

Working closely with Macnica Networks Corporation (TSE:7631), Castelle’s partner and main distributor in Japan since 1992, Castelle has developed an advanced software solution that combines FaxPress Premier with the Fujitsu Interstage suite. The result is a fully automated, enterprise fax solution that enables customers to send faxes through the Interstage List Creator or Interstage List Works software utilizing FaxPress Premier as the fax transport mechanism.

“We see the FaxPress Premier/Interstage solution as an excellent opportunity for continued expansion in Japan,” said Scott McDonald, President and CEO of Castelle. “At the start of 2006, we were preparing for a series of new growth initiatives to do just that—expand. Through these types of partnerships and innovation solutions, we look forward to penetrating new and existing markets with FaxPress™ and FaxPress Premier.”

FaxPress Premier has been approved by Fujitsu as an “Interstage Enabled” product in response to the growing need for large scale fax solutions in Japan. Companies rely on fax for ordering, delivery confirmation, and general communication with customers, vendors and partners, and they often turn to a high performance fax server to fulfill that need. By automating fax communications, businesses are able to take advantage of significant savings in time, money and resources.

Castelle’s FaxPress and FaxPress Premier Network Fax Servers are a complete hardware and software solution that offer every possible network fax option: desktop faxing, production faxing, fax and email integration, workflow application integration, as well as tools for developing custom fax applications. Computer-based, network fax servers offer a high quality, low maintenance enterprise fax solution well-suited for organizations involved in fax-intensive industries.

About Fujitsu and the Interstage Suite
For more information on Fujitsu and the Interstage suite, visit www.fujitsu.com/global.

About Macnica Networks Corporation
Macnica Networks Corporation has over 20 years experience in product localization, sales and technical support of computer network equipment. Macnica Networks supplies a full line of leading network appliances, network software and telecom solutions, and consistently brings innovative new products to their portfolio. Macnica Networks also provides a high level of comprehensive technical support and educational programs to assist their customers with their applications. For more information on Macnica Networks Corporation, visit www.macnica.net. 

If you would like to be added to Castelle's investor email list, please contact Karin Smith at ksmith@castelle.com.

About Castelle
Castelle, a market leader in ‘all-in-one’ network fax solutions for business and enterprise, develops office automation systems that allow organizations to easily implement faxing over local area networks and the Internet. Castelle's network fax servers, FaxPress™ and FaxPress Premier™, provide a simple way to integrate fax with email, desktop and back-end applications. Castelle products are designed to be easy to use and maintain, and provide an economical way for companies to share resources over the network. Castelle was founded in 1987 and is headquartered in Morgan Hill, California. Its products are available through a worldwide network of distributors, resellers, and online retailers. Visit Castelle online at www.castelle.com.

FaxPress™, FaxPress Premier™, FaxPress Enterprise™ and FaxPress Plus™ are trademarks of Castelle. All other trademarks are the property of their respective owners.

Forward-Looking Statements
This press release may contain forward-looking statements. These statements are subject to risks and uncertainties. Investors are referred to the full discussion of risks and uncertainties associated with forward-looking statements as contained in our reports to the Securities and Exchange Commission, including our Forms 10-Q and 10-K. The Company assumes no obligation to update the forward-looking information.

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Contact Information:
Scott C. McDonald
President & Chief Executive Officer
Tel. (408) 852-8000
Fax (408) 852-8100

Karin Smith
Director of Marketing
Tel. (408) 852-8034
Fax (408) 852-8134