How can I get Apple Mail Database to Backup Automatically?

Question

Hello there,

 

I have a habit of exporting apple mail database every month in order to keep the mailbox clean. I was wondering if this method can be automated as it takes a lot of time to export the emails every month. A daily backup or a backup at fortnight without me getting notice of it would save me time as well as the headache of backing up apple mail database every month. Is there any solution or setting of such type available in mac systems?