Configure default Email Client in Catalina

I have Outlook 2016 for Mac on my iMac running Catalina. Currently when I click on a mail:to link in a website it opens Outlook.com web app. I want to change this to open Outlook 2016.

The only way I can find online to do this is within preferences of Mac Mail. This means I will have to configure an account in Mac Mail before I can access the preferences tab which seems crazy.

I don't want mail downloading into Mail as well as Outlook. Is there an alternative way to change this perhaps using command line in terminal?