How to make an email link clickable?

Hi all,

I want to place a mail address in an inline context, and I want to have this address clickable. Means, clicking on it should open the preconfigured mail application with an editor window.

As a replacement for the <email> tag, as known from DocBook, the Mallard manual recommends <sys>. Doesn't work for me, I get the text in a different font, but not clickable. How can I reach this?

Cheers,
Mario