The company said the software is designed to provide access to a simple, centralized place to manage work, school and personal e-mail, even when not connected to the Internet.

USA Today said the program will be offered as a free service with Yahoo! Mail, which is used by more than 250 million people. It is "mashed up" to work with online applications.

Zimbra, a 5-year-old Silicon Valley start-up, was purchased by Yahoo! for $350 million last year, the newspaper said.