When you decide to stop using an email or when switching jobs and others, Google’s Takeout feature lets users backup and export Gmail and other Google account data. Google Takeout, initially released in 2011, is a project by Google Data Liberation Front, which allows users to export their data to a downloadable archive file.
Steps to backup emails from Google account
Step 1: Open myaccount.google.com on a web browser
Step 2: Log on to your Google account
Step 3: Select data & privacy.
Step 4: Click ‘download or delete your data’ option under the head: Data from apps and services you use
Step 5: Choose the data for backup, including Gmail.
Step 6: Choose the file type and particulars for download
Step 7: Click Create Export button