Microsoft’s web-flavored update for Outlook begins rolling out to more testers - Ars Technica

Earlier this year, Microsoft released a preview of a totally redesigned Outlook for Windows client.

Today, Microsoft is taking another step toward that goal, with an updated preview for the new Outlook client that will be available to all Office Insiders in the Beta and Current channels.

Outlook for Windows users signed up for the Office Insider program will be able to try the new app by hitting a "try the new Outlook" toggle in the upper-right corner of the app window; hit the toggle again to return to the old Outlook app.

The Outlook app will also eventually be replacing the free built-in Mail and Calendar apps preinstalled in Windows.

The new Outlook app will be available to all Office and Windows users running at least Windows 10 version 1809, which implies that the Outlook app will replace the built-in Mail and Calendar apps in both Windows 10 and Windows 11 when it's ready to ship.