Is there a way to darken the normal e-mail type face?

   You did not mention what email program you are using or where in the email program you want the type darkened.
   If you are using Outlook Express, I would suggest that you look at Options in the Tools menu.  The Compose Font on the Compose tab can be darkened.  There is also the Fonts section of the Read tab that allows you to make the font bigger or smaller but not darker.

you can also use the bold option.

I use Yahoo mail. sorry I didn't specify/