In the Outlook client (Outlook 2016), you can sometimes retrieve your deleted emails
If you need to restore emails that were accidentally deleted, you may do so using these steps.
1. In Outlook, search the "Deleted Items" folder for missing emails. This can be done using the search box in the toolbar at the top of the email list.
2. If email is not found, right click on the Deleted Items folder name and choose Recover Deleted Items from the dropdown menu.
If emails are not found in either the "Deleted Items" folder or the "Recover Deleted Items" window, the files are unable to be restored.