Select Allow for Trust Gmail to access via Google Gears :
Select the types of shortcuts to create and click OK :
And wait a few minutes, Google will complete the installation process and download the necessary email data to the computer. This period of course depends on the number of email users:
Having done all of the above, we have completed backing up Gmail data to the computer using Offline mode. To open the mechanism to control this mode, click on the small green check icon above the right corner of Gmail, below the account name:
On the other hand, if you want to know the Google Gears data storage location, enter the following path in the Run box:
% UserProfile% AppDataLocalGoogleChromeUser DataDefaultPlugin DataGoogle Gears
and copy the mail.google.com folder:
Good luck!