Certificate errors connecting to Office 365 with Outlook 2016

Scenario
You've just migrated from Exchange to Office 365. You've setup Outlook to connect to Office 365, but now Outlook 2016 is complaining about Office 365's certificate.

The Problem
Outlook 2016 is still trying to use the autodiscovery server registered in your Active Directory. Outlook tries to lookup the autodiscover information in the AD prior to using DNS. You have to stop Outlook from doing that.

Solution
On the client machine, you need a registry entry to stop Outlook clients from using the Active Directory's autodiscover information (supplied by your old Exchange Server).

You need dword entry called ExcludeSCPLookup in HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover.

You can put the following in a .reg file and install the entry by double clicking it. If your machine doesn't have permission to install, open up the registry editor and import the .reg file you create.

Windows Registry Editor Version 5.00
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover]
"ExcludeHttpsRootDomain"=dword:00000001
"ExcludeSCPLookup"=dword:00000001
[HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\AutoDiscover\RedirectServers]
"autodiscover-s.outlook.com"=hex(0):
"autodiscover.hotmail.com"=hex(0):