Downloads the same email over and over

My email just started downloading all my mail that I already received since Feb 2-6 up untill now. So today I have 1138 emails trying to download. But I have already downloaded them. If I close Outlook and re-open it downloads the same emails it just downloaded. I have not waited for it to download all 1138 emails. But now I have 4 x the same emails since Feb 2. I have made sure the setting to keep emails on the server is unchecked.
What else can this be?
Hope this makes since.