Microsoft released new Outlook.com android app for android phones & tablets. You had to use Hotmail android app or Email app with manual settings to get Outlook.com emails on your android device.
Outlook.com android app offers new user interface similar Outlook.com website & Outlook email app on Windows Phones. But It works on android devices having android OS later than 2.3. It does not work for android 2.2 like Samsung Galaxy Ace etc. If you upgraded Hotmail app to new Outlook.com app, You would see same issues on devices using earlier android versions.
You may authentication failed messages If you try to login to new Outlook.com or Hotmail apps. You get this error message even If you enter correct username & password.
How to fix Authentication Failed error messages for OutLook.com or Hotmail android apps
1. As Outlook.com and Hotmail apps work on android versions 2.3 or later, You are getting this error message. You can’t use these android apps. Workaround is, You need to use Email app with manual settings to use Outlook.com email. You can follow the instructions to setup Outlook.com manually on your android phone or tablet.
If you use Email app, You won’t have the functionality Outlook.com android app offers. But at least, You can get Email on your phone or tablet.
2. You can always go to www.outlook.com website on your android device and read your email there If you are still having issues.
You may also get this If you don’t give access to your android device to SEVEN. Seven Networks developed android app Outlook.com with Microsoft.