One of the services I run is a simple email service that lets people send emails from their own websites.
Because it's only a simple email thing, I didn't want to have to install an email client software package such as RoundCube. Instead, I made my own editor, using Markdown.
Why? I thought, because WYSIWYG editors produce such bad markup, I'd use Markdown backed up on the server-side instead.
The question is, is this use of Markdown both effective and accessible? Do I need to do anything to explain how it works to users and that all the extra characters don't appear in the final email? Would I be better using a WYSIWYG editor or even a software package?