Sending, receiving, and organizing email in Outlook.com
Hi Ron Weaks,
If the duplicate messages are only appearing in your Junk folder, it may be worth checking whether they are actually separate emails or simply being displayed more than once in the current view. In some cases, changes to the folder layout or view settings can make messages appear duplicated.
As I have checked and validated, the steps given by AI answer pointed us at the right direction, so you can start by comparing the Message-ID values from two of the duplicate messages.
If the Message-ID is the same, the emails are likely not true duplicates and the issue may be related to how the folder is being displayed.
You can also try viewing the Junk folder from a different browser or an InPrivate/Incognito window to see whether the duplicates appear there as well. This can help determine whether the behavior is related to a browser session rather than the mailbox itself.
If you find that the Message-IDs are different, please let me know and share whether you're accessing Outlook.com in a browser or through an email app, and I'll be happy to help investigate further. Feel free to ask me by clicking "Add Comment" or "Add Answer" if you cannot add comment so your response will be visible. Thanks for your effort.
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