I've had a coworker use <grin> instead of smiley faces. I thought that was a pretty effective way to show emotions while still having a professional looking email.
Yes, back in my BBSing days, using <grin> or (more commonly) <g> was popular before smilies such as :) took off. And when they did, we just called them smilies, even frowny face ones, not emoticons.