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 to.
Click on Websites and Domains tab
Click on Backup Manager in middle section menu.
Click on Back Up
Enter the required backup properties.
The example below runs a full backup of domain example.com during the process splits the backup archive into 2047MB files. The domain is suspended until the backup completes.
The backup process starts immediately you Click Back Up. You can follow the progress on the Current Backups Task - Tab