Microsoft announced last year that it would be retiring the Windows Mail & Calendar apps in favor of the new Outlook at the end of 2024. As of January 1, these apps are no longer functional and will refuse to send or receive any more emails. The apps are no longer available to download via the Microsoft Store, and sideloading the app will result in an error when attempting to setup your account.
"Support for Windows Mail, Calendar, and People ended on December 31, 2024. You can no longer send and receive emails or events using Windows Mail and Calendar" reads a Microsoft support document. The company has also announced that it will be automatically installing the new Outlook app on Windows 10 PCs with the upcoming February security updates, if the user doesn't already have it installed.
