title: iOS how to make email address in a label clickable
body: <p>I believe this question has been asked and answered before, but I couldn't find it. I see an answer pointing to Fancy Label and Three20, but they are not quite what I want, or probably I missed some points.</p>
  
  <p>Basically, I want get app users' feedback, so I will write in a big label, like </p>
  
  <blockquote>
    <p>blah blah, email me at xxxxxx@gmail.com, and blah blah more.</p>
  </blockquote>
  
  <p>I want the email address clickable, and open email composer so that users can edit and send.</p>
  
  <p>That's all I need. How to get it? Thanks.</p>