You can backup your Google Apps emails easily with the help of third-party software. There is a lot of software are available in the market but most of them are not secure. From my personal experience of using the backup tool, I like to recommend MailVita G-suite Backup Tool Expert software which helps you. This will help you to secure your G Suite data, especially during the migration process. This application runs only Mac OS. It also supports all Mac OS versions. Download the free demo version for G Suite backup software.