0xCAA80000 outlook 2016 'You need internet for this'

is this still an issue for you Marcel Alberts?

I was searching for the same solution since I also expeirienced the same issue - 
Here's the solution works for me:

1. Go to Windows Settings
2. Choose Accounts
3. From the left pane, choose Email & Accounts
4. Click/Select your Windows Account and hit Manage button
   1. You'll be redirected to https://account.activedirectory.windowsazure.com/r/#/profile
5. The Click Sign out everywhere
   1. Close the browser
   2. Close the Outlook app and reopen
6. Done

Marcel, have you come any closer to this?

I have the same problem - everything works fine except accessing O365-"things" from office-desktop apps...

I'm also running Windows 10 (1803)

Hi,

Pls. let me the solution if you have because we are facing the same issue. Along with this issue, most of the time a dialog appears and ask to Enter the password continuously where we are using SSO.

'0xCAA80000 outlook 2016 'You need internet for this'

'Enter the password for abc@com'

Thanks in advance!!