Source: Microsoft
Microsoft is bringing a smaller, faster Outlook app to Android soon. The Outlook Lite app promises a "smaller app size with fast performance for low-end devices on any network." According to Microsoft 365's roadmap, it's expected to be rolled out worldwide sometime this month. It seems to be available in some countries, so the company might be prepping for a broader release now.
According to Microsoft's documentation, the app will most likely be only limited to Outlook, Hotmail, Live, and MSN accounts. It won't support school or work accounts.