It looks Mail and Calendar for Windows 10 are out of date. To continue using features like Focused Inbox, junk email management, and calendar search, you'll need to update the apps.
How do I update Mail and Calendar for Windows 10?
To update the apps, select Get updates in the It's time to get updates dialog that appears when you start the Mail or Calendar app.
What happens if I choose not to update?
If you choose not to update the Mail and Calendar apps, you won't be able to use features like Focused Inbox, junk email management, and calendar search. However, you can continue to send and receive messages and create calendar events.
Can I update later?
You can get the latest Mail and Calendar app updates from the Microsoft Store. Go to Start > Microsoft Store, search for Mail and Calendar, and select Update.
You can also update Windows at any time by going to Start > Settings > Update and Security.
When you've downloaded and installed the updates, you will have access to features like Focused Inbox, junk email management, and calendar search.
Note: It can take up to a week for these features to be restored.