Outlook 2016 has a profile creation changes we know about. Specifically, manual profile creation for an Exchange mailbox is no longer available. You must use Auto Discover to create the profile. All previous versions of Outlook using Auto Discover (2007, 2010, and 2013) had manual profile creation as an option if Auto Discover failed. There seems to be another change we weren’t told about.
UPDATE: It appears there is a workaround for this issue if you are willing to live with the restrictions. The Outlook 2016 authentication issue seems to be a change in the profile creation Wizard. The zeroConfigExchange registry value eliminates the Wizard. Bypass the Wizard and it just creates the profile and opens the mailbox. The limitation: Because it disables the Wizard, you cannot create an additional profile or a profile for any other email account but your own. The variant zeroConfigExchangeOnce key allows the creation of additional profiles but the prompt issues return with the Wizard. This behavior is described … Read more