At SevenStrokes, we forego email support and go straight to a forum / discussion-based system based off Vanilla. This is great, because we can organise client discussions much better, focus discussions on certain topics, split and merge topics as they spin off from original topics, and through an intuitive interface that takes no time to learn. Best of all, we can escape from those badly formatted client emails with the annoying 10-line signature and get to the point. That's the reason our discussion post formatting is based off Markdown.
Too bad it's not obvious enough how to use Markdown.
I wrote this very short, basic, and purposely omitting details guide to What is Markdown? - I hope you like it :)