My current default font in writing emails is Helvetica 12pt. I see it as a very small, and I would like to increase it to 14pt. But right now I have to do it every time I write an email, and I often forget it. I would really like to make Helvetica 14pt as my default writing font. And to clarify, I want it to be changed both for me, and for the recipients of my emails, unlike this (seemingly outdated) question.
There are font settings, but they seem to affect only viewing email, as I want to change the opposite matter, writing emails.