Group policy for Outlook 2016 to set default font

hi,

We have a client where multiple users have changes their font within Outlook and we're wanting to keep it set to default for all users, Calibri (Body) font size 11. Looking to set Group policy across the site to get default font for all users.

I have installed Outlook 2016 ADM files but there's no option for font within settings, there is for excel but not Outlook.

Any idea's how I'd accomplish this?

Thanks,

Steven