By default, every item that you delete from your mailbox goes to the Deleted Items folder and stays there until you delete it individually from that folder, or you empty the whole Deleted Items folder. It’s a good idea to empty your Deleted Items folder regularly to avoid wasting space on the mail server.
Using Outlook Web App (OWA)
- Using a web browser, log in to the Outlook Web App (OWA).
- Locate the Deleted Items folder. Right click on it, then select empty.
- Read the warning, click OK to accept.
Using Outlook 2016 (Windows)
- Click File.
- Click Cleanup Tools > Empty Deleted Items Folder.
- Read the warning, then click Yes.
Using Outlook 2016 (Mac OS X)
- Locate the Deleted Items folder within your mailbox.
- Right click on it, then click Empty Folder.
- Read the warning, then click Delete.