title: What is this Perl string encoded in?
body: <p>I'm using use Mail::IMAPClient to retrieve mail headers from an imap server. It works great. But when the header contains any character other that [a-z|A-Z|0-9] I'm served with strings that look like this :</p>
  
  <ul>
  <li><p>Subject : Un message en =?UTF-8?B?ZnJhbsOnYWlzIMOgIGxhIGNvbg==?= (original string : "Un message en français à la con") </p></li>
  <li><p>Body :
  =C3=A9aeio=C3=B9=C3=A8=C3=A8 (original string : éaeioùèè)</p>
  
  <ol>
  <li>What is this strange format ? Is that the famous "perl string
  internal" format ? </li>
  <li>what is the safest way of handling human idioms
  coming from IMAP servers ?</li>
  </ol></li>
  </ul>