How to manage disk usage in Webmail and delete the old emails via Query? 

Step1: Login to the Webmail with your login credentials.

Step2: Click on the storage usage on the webmail home page.

Step3: Choose the Inbox, Sent, Trash or Junk folders and click on Manage.

Step4: Delete the unwanted emails by sorting the emails (older emails or larger sized emails).

Step5: Click on the Permanently delete.