We’ve known this was coming since last year, but for some (such as myself), once you find a product that takes care of your daily needs, sometimes it’s just hard to change or upgrade. While most users have likely migrated to the new Outlook from the Mail and Calendar apps, if you haven’t. Microsoft is now forcing you to do so.
It’s worth noting that to ensure you’re forced to make the change, the apps no longer send or receive mail, won’t work if you try to side-load them, and are removed from the Microsoft Store. From the official Microsoft Support document:
Support for Windows Mail, Calendar, and People ended on December 31, 2024. You can no longer able to send and receive emails or events using Windows Mail and Calendar. Any local emails, calendar events, and contacts stored in Mail, Calendar, and People will remain exportable following the steps in Export emails and contacts from Windows Mail or People and import to new Outlook.
Microsoft is remaining consistent in its recommendation that users try the new Outlook or go to Outlook.com for mail servicing. Starting in February, with an update, the new Outlook will be installed on PCs if it’s not already.