I had the same problem as the OP. Here's how I got Outlook 2016 to work without needing autodiscover.
I could still remember the name of the Exchange 2010 CAS Array that my Outlook profile was configured to connect to under Outlook 2013.
First I pinged that server to get the IP address of the server, then I opened my the file c:\windows\system32\drivers\etc\hosts in notepad as an administrator and added the following line:
'IP address of the server' autodiscover.myemaildomain.com
i.e. 192.168.1.123 autodiscover.mydomain.com
Then I saved the hosts file and reopened Outlook 2016 and everything connected fine.
This will probably only work inside your companies network. It relies on the casarray/server hosting your mailbox having autodiscover running on it even if the DNS records aren't published. If you don't know your casarray's name find a colleague who has
Outlook 2013 still running and look at the name of the server that's configured in their profile.
Good luck.