Do you mean the ZeroConfigExchange?
Based on my test and research, our clients don't have this registry key by default and we need create it in the following locations:
HKEY_CURRENT_USER\Software\Microsoft\Office\xx.0\Outlook\AutoDiscover
(xx represents the current Office version such as 16.0)
HKEY_CURRENT_USER\Software\Policies\Microsoft\Office\xx.0\Outlook\AutoDiscover
Then change the default profile with a new name different with existing ones and create a new profile for this new name in registry key:
Default Profile Setting: HKEY_CURRENT_USER\Software\Microsoft\Office\XX.0\Outlook
New Profile: HKEY_CURRENT_USER\Software\Microsoft\Office\XX.0\Outlook\Profiles
More details about this process: ZeroConfigExchange
Because you are using Outlook 2016, you could use the following .reg file to create these registry keys(Before running them, please backup the original keys and don't change other non-related ones.):
Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover]
"ZeroConfigExchange"=dword:00000001
[HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\office\16.0\outlook\AutoDiscover]
"ZeroConfigExchange"=dword:00000001
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook]
"DefaultProfile"="ZeroConfigExchange"
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Profiles\ZeroConfigExchange]
If you want to apply the ZeroConfig on domain-joined clients, GPO is suggested.