Microsoft Outlook for Mac Backup Situaltion

Question

Hello everyone, I have recently setup my new mac and have installed the latest version of Microsoft Outlook for Mac. I signed in with my 10 years old Gmail account and it had downloaded all the emails successfully. Now I have to use this system only for office purpose so I want to make sure that all the emails are backed up in this system as the Gmail server is almost filled up and I want to perform a cleanup. I also looked up for backup options for Outlook for Mac. I did a backup using the export feature of Outlook for Mac but trust me it was a very lengthy process as there are a lot of emails on my Gmail account. I was not able to understand the Time Machine backup as I only want to backup my emails, not other things. Also, If the backup can be performed automatically that would be cherry on top as going through the export process every week or day would be very excruciating. Kindly let me know any other way to Backup Microsoft Outlook for Mac Automatically.

 

Thanks