Microsoft yesterday announced that they will retire OWA for iPhone, iPad and Android. On May 15, 2018, the OWA mobile apps will stop working.
For the past several years, Microsoft has focused on introducing new features for native Outlook apps on iOS and Android. With an architecture fully powered by the Microsoft cloud, Outlook native mobile apps for iOS and Android offer great user experience. In order to streamline their mobile portfolio, Microsoft has now decided to focus their efforts on developing the native mobile apps instead of OWA apps.
Here’s the timeline Microsoft will follow to retire these apps,
There are some features like shared mailboxes which are currently available in OWA apps but not in native Outlook apps. Microsoft is planning to bring this feature by the end of 2018. In the meantime, users can access them using Outlook web experience through their mobile browser.