We went through this recently at my office. I work for a roughly $25B company. We went through an email migration a few weeks ago that included some rather over-reaching mobile apps.

Long sorry short, it didn't work with Android. The many page readme/instructions they sent for Android users was all iOS screenshots. Seriously, they didn't even prepare for the migration properly by taking the time to test and make instructions for Androids. The half dozen IT experts that flew in to help our migration go smoothly couldn't figure it out. (Even though they said they'd done the migration at other locations).

Their temporary solution was to try every aftermarket email app in the app store until then found one that worked...kinda. But one that wouldn't sync contacts or calenders with Outlook. Ugh.