The Outlook, Calendar, Contacts, and Tasks folders as well as certain Outlook and Calendar subfolders can be downloaded as a .pst file.
Note: If you download the Deleted Items folder under Outlook, only the mails in the folder, and not deleted Calendar, Contacts, or Task items will be downloaded.
Download the .pst file
1. Navigate to the Outlook folder you want to recover and make sure you select the snapshot from the time you need.
2. Select the more options icon to the right of the folder and then select Download as .pst.
3. You will see a message the that link will be generated. Depending on the size, it may take some time. As soon as it is generated you will receive a notification in the app as well as a a separate email with a link to download the file.
4. Click the link and the file will download to your computer.
5. Now you can either open the file on your computer to see the content or import the data back into Outlook.
Import data back to Outlook
Once you have downloaded the .pst file, you will can directly mount the data back into Outlook using Outlook's import feature.
For details on how to do this, please refer to Microsoft's article here.
Where will the imported data be located?
If you import the whole Outlook folder, then in Outlook you will see a new folder named "Outlook" with all the data. As the restored data will be located in a separate inbox, you can view it in parallel with the current inbox. You can then simply drag and drop data between the two inboxes to bring back lost mail. Or you right click on the mail you want and select Move to place it in a different folder. If you import an Outlook subfolder, for example the "Inbox" folder, then the individual mails in the folder will be restored back to their original locations.
If you import a calendar that has been deleted from Outlook, then a new calendar with its items will be created under My calendars. If the calendar you are importing is still present, then the individual calendar items will appear back in that calendar.
If you import Tasks, the tasks will return to your Tasks.
If you import Contacts, the contacts will return to Your Contacts.