Emails won't use the font (Arial 11pt) I have selected in settings

Emails won’t use the font (Arial 11pt) I have selected in settings 

I’m having similar trouble - I have set the default font size to 10 but when I compose an email the font size is 12. Have changed multiple times but the problem persists. Any ideas?

See if maybe this helps–

Nailed it Jay. You’re the man.

That setting is for viewing plain text messages, as HTML messages have their own font specs so will not change. I think it should be more clear what it does. To set a different size for composing messages, the best option is to create a template with the required size.