title: Getting hidden values in classic extractor
body: <p>I have a classic extractor that gets some data, including an email. When I train it, I'm asked to tell if I can see the data after clicking on "detecting optimal settings", and since I can't see the email, I hit "no".</p>
  
  <p>The extractor later extracts everything, including the email, but when I save this extractor and want to use it with a bulk of emails, it doesn't work. It just seems it worked for that first time, but it doesn't work again.</p>
  
  <p>Anybody has the same issue? </p>