The company said that its is developing and testing offline capabilities that allow users to read compose and archive messages while offline. New messages are sent when the user reattaches to the network.

The service is built on the two-year-old Google Gears platform, which already is the foundation for offline access in Google Docs, Google Reader, and a handful of third-party Web applications.

The offline access allows users to load the Gmail client without a network connection. The feature initially will be only for U.S. and U.K. English versions of the client.

Such offline features for e-mail clients have been available for years from major corporate messaging vendors such as IBM/Lotus, Microsoft and Novell. Offline capabilities are a must-have feature if Google hopes to make significant inroads with corporate customers on the back of its Google Apps Premier Edition (GAPE), which includes Gmail.

"This is a major step along the way," writes Joyce Sohn, Google Apps marketing manager on . She cautioned users that not all the "kinks" have been worked out yet.