Microsoft is testing a new Outlook application that will replace its Mail and Calendar applications integrated with Windows 10. Code-named Monarch and “One Outlook”, the application is “a new version of Outlook designed for big screen experiences,” according to leaked version of the application.
Although the leaked application will not work without a full internal Microsoft account, the One Outlook application will replace the desktop versions (win32 and UWP) of Outlook, Outlook Web Access (OWA) and the macOS desktop client. Microsoft is also hosting the full web version of this new Outlook online.
Microsoft is building a single desktop client that will be based on the web version of Outlook. The leaked application is clearly in an initial state, and Microsoft even warns employees that it is currently designed for “courageous dogfooders” and does not include an offline mode. Dogfood is a term used by Microsoft and other software companies to test and use previous versions of their own code.
This previous version was leaked, but a final replacement for the Windows 10 Mail app may not arrive until next year. Windows Central reports that this client is likely to enter a larger viewing program in late 2021, with the goal of replacing the Mail and Calendar apps on Windows 10 in 2022.