There are three methods to do so The first is that you can use MS Outlook which is a great way it's free the only problem is that it is time-consuming and if you choose the wrong tab you have to repeat the process. The other method is through Google Takeout it's not recommended at all as the problem is that first, you get a limited chance to backup, and second it changes the file to MBOX which eventually you have to convert to a PST file using some software so the best I can suggest you is to go for Sysinfotools Google Backup Tool it is automated and faster saves your lot of time just with few inputs you can get your desired result I use this.