Rant mode on: I really wish that people stopped being creative when sending emails. Do not use different font, font sizes, font colors, backgrounds, etc., it just makes your email harder to read. Hint: black text on dark gray background isn’t easy to read.
Think about the reader of your email, it’s not certain that this person is reading your email on the same type of device you are, and the receiver might have different problems reading, or bad eye sight, etc.
I’m one of the people who have problems with bad eye sight and sometimes it’s almost impossible to read an email, or it takes a lot of time.
Someone might say: use an email client where you can control this … yep, that works IF your allowed to use another email client (I’m stuck with Mail which doesn’t allow me to control this).
In short: just send the emails as “plain text” and let the receiver control font sizes, font colors, backgrounds. I have no problem with HTML emails that just contain structural markup (headings, lists, etc).
Rant mode off.