title: add original subject to mailto link
body: <p>Hello I wan't to put a simple Unsubscribe link in all outgoing emails. So far I have this:</p>
  
  <p><code>&lt;a href="mailto:yourlist@yourdomain?subject=Unsubscribe"&gt;Unsubscribe Me&lt;/a&gt;</code></p>
  
  <p>The problem is that in the mail I'd also like to have the original e-mail's subject and sender</p>
  
  <p>Is it possible to dynamically build a link that would also include original message's sender and subject?</p>
  
  <p>Thanks</p>