While I am disappointing, I'm not exactly surprised. I'm willing to bet that this is in response to the Windows 10 Mail App, which was a lightweight metro app that Microsoft depreciated to try to push people to use it's new outlook app. People hated it, so they downloaded older versions and shut off app updates. Eventually, Microsoft did a server side switch that essentially broke functionality on the old app with outlook emails, although other providers work fine (for now).