Frequently Asked Question

How to Prevent outlook from trying office 365 logon.

1. Open regedit and navigate to 
   HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\AutoDiscover
2. Create a DWORD (30-bit) value for ExcludeExplicitO365Endpoint and change the value to “1” to enable it.
3. Close Regedit and add the mail account to outlook.

This is sometimes needed when you have a user that has both a 365 account and an on-premis e-mail account.