Google has sent a notification to all users below Android 3.0 edition. Every user of Android 2.3, it is the lowest one allowed, has to update their software to Android 3.0. The ones who are using Android 2.3 cannot reach Google related apps like Gmail, Youtube, Google Playstore etc.
According to Google’s releasement, the users of Android 2.3 will not be able to log in their Google accounts in their devices. As a result they cannot use Gmail, Playstore, Google Maps, Google Calendar, too.
Why doesn’t Google support lower Android versions? The answer is pretty easy. The bugs, hackers can easily enter those systems rather than others. So the company wants to make it more secure and convenient.