In order to save space, you can delete the email history after setting a certain date and deleting the messages received before.
For example, messages received a week, two weeks, one month or a year ago can be deleted. Follow the below steps for execution:
1- Login to your control panel (cPanel).
2- Choose (Email Disk Usage) from (Email) block.
3- Select the email address you want to delete its messages.
4- Press (Manage) in front of the folder name.
5- Set the time that you want to delete messages before by pressing (Messages to delete), then press (Delete Permanently)
Note: Any deleted messages can not be restored, so kindly choose messages accurately before the deletion process.