Why Outlook shows duplicate emails

I also wondered about this when I saw the same emails multiple times and started reading about duplicate messages in Mac Outlook. The main reason I found was that Outlook sometimes fails to sync properly with the server. If it cannot confirm a download, it simply downloads the email again. Email forwarding rules can also create duplicate copies without clear indication. In some cases, corrupted Outlook data files may contribute to the issue. All of this can make the inbox cluttered and hard to navigate. I checked my rules and fixed some configuration issues, which helped reduce duplication. Regular cleanup also keeps things under control.