Outlook with local exchange account asking for Microsoft online login

I seem to have more and more issues with Microsoft pushing to try and force everything into their online service lately.

As of today I suddenly have two workstations that refuse to stay connected to Exchange. This is a local domain and a local Exchange server. Out of the blue they now pop up with a Microsoft online login window on start-up. If I close the window, the account status changes from being happily connected to Exchange to "Needs Password".

The login box is pre-populated with [email protected], and trying to click next just errors that "This account isn't on our system" (yeah, big surprise, it's a local domain, local exchange and nothing to do with Microsoft online).

What am I supposed to do about this? What is the correct way these days to let my users connect to their local exchange account without Outlook demanding they log into a non-existent Microsoft online account?

You could follow the steps to create ExcludeExplicitO365Endpoint registry value to bypass connection to O365.

1.Press win+r, then type regedit on the outlook client.

Find the below path. (If you do not have the AutoDiscover key, please create it under the HKEY_CURRENT_USER\Software \Microsoft\Office\16.0\Outlook.)

HKEY_CURRENT_USER\Software \Microsoft\Office\16.0\Outlook\AutoDiscover

2.Create a new DWORD parameter named ExcludeExplicitO365Endpoint and value 1 , then restart Outlook. 3. Check if the issue persists.