There are actually four "outlook" implementations now.
1. Outlook desktop - old MFC / win32 crapfest
2. Windows Mail / Calendar - new WPF crapfest.
3. O365 online outlook / outlook.com - fat web app.
4. "New" Outlook - this is a fat Electron style app based on the web app.
The latter is actually pretty good - been using it for a couple of months. This is apparently going to replace all the other ones on the desktop.