To troubleshoot why your emails are being marked as read in Outlook, follow these steps:

1. Check for Rules – First, check any rules or filters you may have set up in Outlook. Such rules may be automatically marking emails as read when they arrive.
2. Check the Automatic Preview Settings – Outlook may be automatically set to preview emails. To turn this setting off, go to View in the main menu, click Reading Pane and select Off.
3. Disable Desktop Alerts – You may also want to disable any desktop alerts you currently have set up in Outlook. Go to File in the main menu, click Options, then select Mail and then go to the Desktop Alert setting.