Solution: In coolpad its not easy for delete my google account without my dataLoss.But its hard to find an option to delete the account in the phone. Steps: Goto your settings app and select accounts it will show you the accounts you synced with your device. Then long press the left option under your phone(square option under the display that we are using the closing of apps that are in background). Then it will show you remove the account.then select the option and delete the mail account from phone