title: PHP mail don't send anything
body: <p>I ran this PHP script in a dedicated server (OVH Kimsufi, Debian 6.0 stable).</p>
  
  <pre><code>&lt;?php
  $msg = "coucou les amis";
  $sub = "test";
  $head  = 'From: webmaster@example.com' . "\r\n" . 'Reply-To: webmaster@example.com' . "\r\n";
  echo mail("31415@yopmail.com", $msg, $msg, $head);
  ?&gt;
  </code></pre>
  
  <p>Mail returned 1 but the email was never received... How to fix it ? </p>