First, log into your Plesk control panel and then click on Domains from the main menu.
Click on Domain Name which you would like to add the new email account.
Click on Websites and Domains tab
Click on Backup Manager in middle section menu.
Click on Scheduled Backup Settings icon.
Enter the required backup properties.
The example below runs a full backup of domain example.org during the process splits the backup archive into 2047MB files. The number of backups to retained has been set to 2 and runs daily at 06.00 and sends an email if any error in the backup process.