Google Takeout is a free backup service for saving data from a Google account. It's designed to download data from various Google apps. Not only Gmail mailbox data, but also from Drive, Calendar, Contacts, YouTube, Keep, Hangouts, Play Store, and many more.
Google Takeout supports over 50 types of data, including mailbox settings, search history and locations. Once the user has selected the data to save, Google Takeout prepares a ZIP file for downloading. A large ZIP file can be automatically split into smaller pieces for ease of downloading. Each data type is saved in a specific file format inside these ZIP archives. For example, the MBOX format
for email messages.