Introduction

Have you ever deleted something that you did not want to delete? The Exchange email system allows users to recover their deleted items at their own convenience, even after those items have been emptied from the "Deleted Items" folder. The retention time period for deleted items that have been emptied from the "Deleted Items" folder is 14 days. To recover your deleted items, follow the instructions below.
 

Outlook 2016 / 2019 (Windows)

1. Launch Outlook and from the left sidebar, select your mailbox, then select Deleted Items.

2. Navigate to the Home tab. Under the Actions group you will see a Recover Deleted Items from Server button.

3. Click that, then select the message you wish to recover.

4. Ensure that the Recover Selected Item radio button is selected, then click OK to recover the item.

More details are available on Microsoft's website in the article Recover deleted items in Outlook for Windows

More details are available on Microsoft's website in the article Recover deleted items or email in Outlook on the web