How to Delete and Restore Items in Outlook
Many organizations limit how much space Outlook can take up. Deleting old emails and objects helps keep you within that limit.
Press the Delete key.
The item is deleted and moved to the Deleted Items folder.
To permanently delete the messages in your trash folder, right-click the Deleted Items folder in the Navigation Pane and select Empty Folder.
If you realize that you deleted something accidentally, you can usually retrieve it.
Here you'll see deleted messages, calendar events, contacts, and tasks.
The item is restored.