title: Send a mail with Corona
body: <p>In the line:</p>
  
  <pre><code>local mail1 = native.showPopup("mail")
  </code></pre>
  
  <p>I receive:
  Runtime error: /Users/liorbruder/Documents/main.lua:18: attempt to call field 'showPopup' (a nil value).
  It looks like Native UI doesn't have a "showPopup" property. What I miss here?
  And how can I send email with Corona?</p>