O2 UK Expands Partnership With Critical Path; Deploys Memova Platform for Converged Services.

Memova Enables O2 UK to Bridge the Gap Between Mobile and the Internet

SAN FRANCISCO -- Critical Path, Inc. (OTC:CPTH), a leading provider of messaging software and services, today announced that it has expanded its partnership with leading operator O2 UK. As part of its initiative to deliver new converged messaging services to consumers, O2 has upgraded its messaging systems, deploying Critical Path's Memova[R] platform.

With a focus on delivering services that integrate mobile and the Internet, O2 needed a messaging platform that could provide a scalable, flexible, consumer-oriented foundation for converged services. Memova enables a variety of converged services for consumers, including mobile email, advanced multimedia messaging and communications, and integrated access to personal information and content. These services simplify and unify the consumer experience across both mobile and fixed-line connections.

"We are committed to delivering the best possible experience to our 17 million customers, providing services that are seamlessly integrated and easy to use as our mobile and broadband worlds increasingly converge," said Mike Fairman, Head of Broadband, O2. "Critical Path provided the underpinnings to our existing Web-mail platform and Memova provides us with flexible, bolt-on features that allow us to extend the experience to our mobile customers."

With the Memova platform now in place, O2 will work with Critical Path to roll out new converged messaging services in 2007.

"We're pleased to help O2 expand its messaging services through our Memova platform," said Robert Zuber, Chief Mobile Strategist, Critical Path. "O2's strategy is directly aligned with ours, which is to provide easy-to-use, seamlessly integrated services with anytime, anywhere access. We look forward to working with O2 to bring a variety of new converged messaging services to market."

About O2

O2 is a leading provider of mobile services to consumers and businesses in the UK. These services include voice, text, media messaging, games, music and video, as well as always on data connections via GPRS, 3G and WLAN. Every month, O2's 17 million customers send well over a billion text messages. O2 owns 50% of the Tesco Mobile joint venture in the UK as well as having 100% ownership of Be, a leading UK fixed broadband provider.

O2 UK is part of Telefonica O2 Europe which has more than 35 million customers across Europe. Businesses includes a mobile network operator in Ireland, integrated fixed/mobile businesses in Germany and the Czech Republic, and O2 Airwave - the emergency services network in the UK. The company also recently won a mobile licence in Slovakia, where it plans to launch service in 2007.

About Critical Path, Inc.

Critical Path's Memova[R] solutions provide a new and improved email experience for millions of consumers worldwide, helping mobile operators, broadband and fixed-line service providers unlock the potential of email in the mass market. Memova[R] Mobile gives consumers instant, on-the-go access to the Messages that Matter[R] most. Featuring industry-leading anti-spam and anti-virus technology, Memova[R] Anti-Abuse protects consumers against viruses and spam. Memova[R] Messaging provides consumers with a rich email experience, enabling service providers to develop customized offerings for high-speed subscribers. Headquartered in San Francisco with offices around the globe, Critical Path's messaging solutions are deployed by service providers throughout the world. More information is available at www.criticalpath.net.

Forward-Looking Statements: This press release contains forward-looking statements by the Company and its executives regarding the performance of our product and service offerings, the future release of our products and services and our customer's products and services which include our offerings, the ability of our customers to achieve cost savings and improve revenues in the provision of services, industry trends, market and customer requirements, the ability of our products and services to meet the business needs of our customers, and the market for products and services like ours. The words and expressions "look forward to," "will," "can," "expect," "plan," "believe," "seek," "strive for," "offers," "anticipate," "hope," "estimate" and similar expressions are intended to identify the Company's forward-looking statements. These forward-looking statements involve a number of risks and uncertainties that could cause actual results to differ materially from those anticipated. These risks include, but are not limited to, our evolving business strategy and the emerging and changing nature of the market for our products and services, our ability to deliver on our sales objectives, the ability of our technology and our competitors' technologies to address customer demands, changes in economic and market conditions, and software and service design defects. These and other risks and uncertainties are described in more detail in the Company's filings with the U.S. Securities and Exchange Commission (www.sec.gov) made from time to time including Critical Path's Annual Report on Form 10-K for the fiscal year ended December 31, 2005, Forms 10-Q for the three months ended March 31 and June 30, 2006, and Current Reports on Form 8-K, as may be amended from time to time, and all subsequent filings with the United States Securities and Exchange Commission (www.sec.gov). The Company makes no commitment to revise or update any forward-looking statements in order to reflect events or circumstances after the date any such statement is made.

Note to Editors: Critical Path, the Critical Path logo, Messages that Matter, Memova and the Memova logo are the trademarks of Critical Path, Inc., registered in various jurisdictions. All other trademarks are the property of their respective holders.