We reported last week that Microsoft is working hard on improving the dark mode experience on Mail and Calendar app. A couple of months back we reported that Microsoft might be planning to add a toggle in the Mail and Calendar app to switch between Dark and Light mode. The toggle will allow users to easily switch between dark and light mode instead of going into Settings and then changing it.
— Ajith (@4j17h) January 17, 2019
Additionally, a toggle will allow users to switch just the right panel to dark or light mode. It might come handy for those who like keeping a mix of dark and light mode on their devices.
Not only that, Microsoft might be planning to make it easy to switch accounts even when the sidebar is minimized.
Today Neowin reports that the updated app is rolling out to Windows 10 Insiders on the Fast Ring. We do not know when the update will be coming to regular users, but it will likely not be too long after.