Microsoft is said to be working on a new email client for
Windows 10 and macOS, and this time, it’ll be based on the web
version of Outlook. Microsoft is also planning to retire the
specialized UWP Mail app, which was introduced in 2015 when the
tech giant was betting big on the ‘universal’ apps approach.
Currently, Windows 10 offers a variety of Outlook clients, such
as the Win32 version and the built-in Mail and Calendar.
Microsoft is planning to unify the Outlook desktop clients
by embracing a common technology, as it was previously hinted
at Ignite conference in 2020.
The upcoming Outlook app for Windows 10 is codenamed “Project
Monarch” and it will be much smaller than the existing Mail and
Calendar app. It is also going to have support for Windows 10
native functionalities, like Action Center and Windows Share
Microsoft will offer the app via Insider channels later this
year. However, some users with Azure organization account have
already managed to access the client after it was leaked on
As you can see in the above screenshot, “One Outlook” app for
Windows 10 is completely based on the web version of Outlook
and the client appears to be using Microsoft Edge to serve web
The app is in the early stage of development and it currently
feels more like an HTML5-based web wrapper that you can already
install using Chrome or Edge, but it has better support for
System requirements for One Outlook
In one of the documents, Microsoft has described Monarch as a
new version of Outlook designed for large-screen experiences
running Windows (Intel and ARM) and macOS.
Unlike the UWP version, One Outlook client will be updated on
the same cadence as Microsoft’s website with its own feature
roadmap and schedule.
As we mentioned at the outset, a preview version of the Outlook
app is expected to launch later this year. The existing Mail
app is in maintenance mode, but it will still receive updates
in 2021 because the new Outlook app won’t be ready until next