Castelle Announces Release of New FaxPress Plus™ 5.0 Fax Server Software at Microsoft Tech-Ed 2007 in Orlando

Business Wire, June 4, 2007

* Windows Vista Compatibility

* Office 2007 and Exchange 2007 Compatibility

* PDF Print Driver for Windows Vista

* New MFP Support for Ricoh, eCopy, EFI and Sharp

MORGAN HILL, Calif. & ORLANDO, Fla. -- Castelle[R] (Nasdaq: CSTL), a leader in 'all-in-one' network fax solutions for the business and enterprise markets, today announced that it will be demonstrating it's new FaxPress Plus[TM] 5.0 software at the 15th Annual Microsoft Tech*Ed Conference and Exhibition at the Orange County Convention Center in Orlando, Florida, June 4 - 7. FaxPress Plus 5.0 is the newest fax software for Castelle's FaxPress Premier[TM] and FaxPress Enterprise[TM] family of network fax servers.

"We look forward to demonstrating our new FaxPress Plus 5.0 software at this year's Microsoft Tech*Ed," said Scott McDonald, President and CEO of Castelle. "As a Microsoft Certified Partner we are committed to continuing the development of fax solutions for Microsoft applications, and this year is no different. Our new FaxPress Plus 5.0 and FaxPress[TM] 9.0 software suites are designed to integrate with a Windows Vista, Office 2007 and Exchange 2007 environment, and provide a number of additional new features that will help our customers work more efficiently."

FaxPress Plus 5.0 client and server software has been enhanced for greater fax server reliability and performance. New features include:

* Windows Vista, Office 2007 and Exchange 2007 Compatibility The FaxPress Plus 5.0 client is fully compatible with all editions of 32- and 64-bit versions of Windows Vista, as well as Microsoft's new Office 2007 suite and Exchange Server 2007.

* PDF Print Driver for Windows Vista Easily convert documents from virtually any application into a PDF using this handy utility.

* New Multi-function Product (MFP) Integrations FaxPress Plus 5.0 includes integration for Ricoh GlobalScan, eCopy 4, EFI and Sharp OSA-enabled multi-function devices.

Additional FaxPress Plus 5.0 features include:

* Alert Service - automatically send an email when predetermined events occur in the FaxPress Plus server.

* Performance Monitor - monitor real-time FaxPress Plus server performance using the familiar Performance Logs and Alert Service.

* Castelle Fax Viewer - preview received faxes directly in the FaxPress Plus client application

* Incoming Fax Time Stamp

* Improved Archive Functionality

Castelle will be among 250 Microsoft partners exhibiting at this year's Tech*Ed Expo in Orlando. Microsoft Tech*Ed attracts more than 12,000 attendees, providing them with hands-on training, educational sessions, and the opportunity to see firsthand all the latest technology from Microsoft and its partners. For more information on Microsoft Tech*Ed 2007, visit http://www.microsoft.com/events/teched2007/default.mspx.> FaxPress Plus 5.0 Availability

FaxPress Plus 5.0 will be available on June 18, 2007. For information on software upgrades, hardware trade-ins or evaluations, please contact Castelle Sales at (800) 289-7555 or online at www.castelle.com.

About Castelle

Castelle (Nasdaq: CSTL), a market leader in 'all-in-one' network fax solutions for business and enterprise, offers organizations every possible network fax option: desktop faxing, production faxing, fax and email integration, workflow application integration, and tools for developing custom fax applications. FaxPress[TM], FaxPress Premier[TM] and FaxPress Enterprise[TM] network fax servers include the FaxPress or FaxPress Plus[TM] software suite that enables administrators and users to perform functions such as managing fax queues, creating reports, and viewing fax archives.

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

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

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.