If you experience an issue with Outlook randomly deleting emails from your Inbox or need to recover an email that you have accidentally deleted, then read on.
Please check what rules are on Outlook by going to the Folder tab and run Rules now tab
You can also try to recover deleted email via the Outlook web view (go to office.com) you get an option in the Deleted folder to recover deleted items. These are emails that you may not be able to see in the Deleted folder.
It will pull a lot back but if you are worried that something had been deleted and then it has expired and been removed from the Deleted folder, then you can try pulling these files back and having a look. As you can see, it may cause you more work with so many files pulled back.