Hi @Steve Bowen ,
According to your capture, there seems to be two more duplicated mailbox in your email folder list, does the "shows up 3 times" you mentioned mean that each email message you received will show up in all the three same mailbox?
If yes, may I know how does it look like in your Outlook Account Settings? It is suggested for you to check if there is any duplicated items under the Email Tab and Datafile Tab via Outlook > File > Account settings > Account settings for example like below.
If there indeed exists duplicated items within the "Email" tab or "Datafile" tab, please try to remove those you do not would like via the "Remove" option and then restart your Outlook to see if your issue could be resolved.
If there is no duplicated items within your "Email" tab or "Datafile" tab, as I know, a corrupted profile can lead this issue, so please try creating and using a new Outlook profile via Control Panel > Mail > Show profile and see if there is any difference. (Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.)
Hope this can be helpful.
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