I am trying to figure out how to show an image or at least change the text shown of a URL link that gets put into an email. Basically, I have a "Send for Approval" button on a form that automatically ...
As the SO thread states the mailto protocol does not support HTML although there is a possibility that upon receipt some email clients may convert text that appears to be a URL into a clickable link. This behavior is entirely dependent on the email client of the receiving user.
Using script you can hijack the action main?a=userwin to send HTML as suggested by these two screenshots: