I'm a big fan of Windows Mail & Calendars due to it's simplicity. Personally find it more intuative for a daily use cases compared to Outlook desktop. Seeing Microsoft deprecating it and forcing millions of people to use the new Outlook dragged me into start working on Wino couple years ago. Wino's main motivation is to bring all the existing functionality from Mail & Calendars overtime without changing the user experience that millions loved since Windows 8 days in Mail & Calendars.