Using Classic Outlook on Windows for personal email, calendar, and contact management
Hi. I'm Brian and I'll try to help.
It might help if you were to state your mail provider and what type of account (POP, IMAP, Exchange) you're using. Often important when discussing a mail client.
Several things come to mind. First, look at your folder list in the left-hand pane to see if any of your folders have the > symbol next to their name. If so, expand it and see if your folder is there. This includes the Deleted Items folder. Additionally, click the root of your data file to see if anything is contained therein. Depending on how you have the view of the root configured, you might see contents in it.
If this doesn't help, let me know.