Until this day ,a big of the big draw backs of Gmail is that you cannot view your emails when you were offline. It happned to be changed.Cause gmail was offline. Rolling now , Google have made a Google Gears version of gmail with the use of Gmail labs. If you don't see it new,try and try to check it.

If you have installed the Google Gears version to your browser, Gmail now can detect if you are offline.It caches your email so you can view your email or even starring the emails even you are offline, etc....That cache was synchronized with Gmail's servers When you are again online and connected to the internet , it sends the messages you have decided to send.You can even open attachment , etc. . The same features on the way Gmail on mobile phones such as Android and those phones that support Gears.

The off line system is currently in beta and it is available only with the use of Google Labs. Some of the features of Gmail won't possibly work but some important features like spell check still do work.