Mail App: Incoming Message Font

Hi, I have searched the forum and hope that this is not something which has previously been answered.

The majority of incoming emails use the Microsoft font 'Calibri' which is not available on Mac by default. As a result all incoming mail displays as 'Times New Roman' which I find difficult to read on screen.

Is there a way to set a default font, or set the substitute font to something more readable?

I have looked in Mail Preferences, which only sets the default font for outgoing messages.

Please Help.