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According to your description, it seems that your Windows Mail is updated to New Outlook.
Beginning in 2024, new Windows 11 devices will be shipped with the new Outlook for Windows as the default mailbox application free for all to use. The Mail and Calendar applications will continue to be available via download in the Microsoft Store through December 31, 2024. After this date the Mail & Calendar applications will no longer be supported. On existing devices, users can switch to the new Outlook for Windows from a toggle in the Mail and Calendar applications. You can see more information about accessing the People app here.
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