How to Disable Google Fonts?
We understand that some users are not happy about loading Google Fonts, and that’s why we have a hook “mailpoet_display_custom_fonts” that users can use to stop loading it.
You simply need to add this code snippet on your theme's functions.php file:
add_filter('mailpoet_display_custom_fonts', function () {return false;});
Please note that this will stop the Google Fonts to be loaded, so if you're using templates or forms containing any Google Fonts, they won't work.
Read here how to add code snippets, like the one above, safely to your WordPress: How to add Code Snippets to your Website.