title: USING Regular Expressions to Find IP Address from Email Header
body: <p>I have a question that i need to grab IP address from the following part of Email Header.</p>
  
  <pre><code>Received: from smtprelay.b.mail.com (smtprelay0225.b.mail.com. [11.11.11.11])
      by mx.google.com with ESMTP id g7si12282480pat.225.2014.07.26.06.53.24
      for &lt;a@gmail.com&gt;;
  </code></pre>
  
  <p>I need the output only 11.11.11.11 using regular Expression in python.</p>
  
  <p>An Help will be appreciated.</p>
  
  <p>thanks.</p>