When using Outlook 2016 the account settings page doesn't show the normal "Incoming mail server" and "Outgoing mail server (SMTP)" settings.
To alter the server settings you need to go into "Account Settings" and select "Manage Profiles" NOT "Account settings".
Once in "Manage Profiles" click "Email Accounts..."
Then select the email account and click "Change".
You should now see the missing options to set the incoming and outgoing mail server names.