So Outlook released a new app today for iOS and Android.
This is differnt to the app and OWA app but is set to replace them

more details here

I've just downloaded the Android app and first impressions are pretty promising, a few points of interest.

  • It's showing the <title> before the preheader.
  • Pretty good media query supports, including @supports
  • Strips all form elements so no checkbox hacks
  • Shows img linked SVG but not inline <svg> tags
  • CSS animation works

We can only hope this is what they have planned for the new Windows 10 Outlook (but I'm fearful).