Critical Path Files Patents Worldwide Covering Secure Messaging, Collaboration, and Wireless Communication.

Business Editors/Technology Writers

SAN FRANCISCO--(BUSINESS WIRE)--April 24, 2000

Patents Bolsters Critical Path's Commitment To Provide Secure

Internet Messaging Anywhere, Anytime, And On Any Device

Critical Path Inc. (Nasdaq:CPTH), the dominant global provider of business-to-business Internet messaging and collaboration solutions, today announced it has filed three patents worldwide to protect the technology at the core of its current and future services. These patents cover technology used in Critical Path's Secure File Services, Internet and wireless messaging, and the use of digital certificates.

Critical Path's Secure File Services are based on its patent-pending technology and enable businesses to securely send, store and collaborate on files from anywhere in the world via the Internet. As the only allsource provider for advanced Internet messaging and collaboration solutions, Critical Path's Secure File Services provide additional flexibility and functionality for businesses to leverage the Internet in order to improve communication and collaboration.

"Critical Path is committed to staying at the forefront of the messaging market and these patents enable us to protect the proprietary technology and intellectual property that enables Critical Path to be such a dominant force in the market," said Doug Hickey, CEO of Critical Path. "As a trusted provider of Internet messaging solutions it is our duty to protect the services and technology our customers put their confidence in."

Critical Path has also filed patents worldwide surrounding the use of digital certificates in a collaborative environment as well as the ability to access this environment in a secure way from wireless devices worldwide. Both patents enable the exchange of secure, authenticated, and confidential information among individuals or groups regardless of whether they access the information from a traditional Web browser or a wireless device.

"Corporations need secure messaging solutions that match the way they communicate both internally and externally," said Mike Serbinis, chief security officer of Critical Path. "These patents, filed by Critical Path, cover Internet messaging as well as wireless messaging to ensure our customers can communicate securely regardless of the device they are using."

About Critical Path, Inc.

Critical Path, Inc. (Nasdaq:CPTH) is the dominant global provider of complete end-to-end Internet messaging and collaboration solutions for wireless, Internet-centric, telecommunication and corporate businesses. Through its allsourcing strategy, Critical Path is the only advanced messaging provider to offer businesses the flexibility to outsource, midsource or insource all or part of their messaging and collaboration applications. Critical Path has built an industry-leading global infrastructure with data centers connected to key Internet exchange points. Critical Path's technology currently reaches more than 100 million end-users through its customer relationships including more than 25 million wireless devices. Critical Path provides reliable, secure, and scalable e-mail and a flexible suite of enhanced messaging services to partners such as E*TRADE, CompuServe, Network Solutions, U S West, Sprint, France Telecom, British Telecommunications, and ICQ. Critical Path is headquartered in San Francisco, with offices in locations nationwide and in Germany, England, Ireland, France, Denmark, Italy, Switzerland, Brazil and Argentina. More information on Critical Path can be found at www.cp.net.

The statements in this press release relating to matters that are not historical are forward-looking statements. Actual results could differ materially from these forward-looking statements. Risks and uncertainties facing Critical Path are described in its prospectus dated June 1, 1999 and with its periodic filings with the Securities and Exchange Commission (www.sec.gov).

Note to Editors: Critical Path and the Critical Path logo are the trademarks of Critical Path, Inc. All other trademarks are the property of their holders.