To backup Gmail, follow out the following steps thoroughly:
Click on myaccount.google.com for your Gmail data recovery.
Under the Privacy and Personalization drop-down menu, go to "Manage your data & personalization."
At the bottom corner of the screen, you will find "Download or delete your data." To backup your Gmail data, click on download data.
Now to set the recovery platform where this data will get stored, go to "Delivery method,"
From there, click on the location of your preference out of the following options: OneDrive, Google Drive, Box, or Dropbox.
That's all. After completing the above, the system will set up your data backup. However, it may take some time, depending upon the total file size.