IMP_Contents::getHeader PHP Method

    public function getHeader($type = self::HEADER_OB)
    {
        return $this->_getHeader($type, false);
    }

 /**
  * @see showInlineImage
  */
 protected function _showInlineImage(IMP_Contents $contents)
 {
     global $injector, $prefs;
     if ($this->alwaysShow || !$prefs->getValue('image_replacement')) {
         return true;
     }
     if (!$contents || !($tmp = $contents->getHeader()->getHeader('from')) || !($from = $tmp->getAddressList(true))) {
         return false;
     }
     $res = $injector->getInstance('IMP_Contacts')->searchEmail($from->first()->bare_address, array('email_exact' => true));
     if (count($res)) {
         /* Don't allow personal addresses by default - this is the only
          * e-mail address a Spam sender for sure knows you will recognize
          * so it is too much of a loophole. */
         $res->setIteratorFilter(0, $injector->getInstance('IMP_Identity')->getAllFromAddresses());
         foreach ($from as $val) {
             if ($res->contains($val)) {
                 return true;
             }
         }
     }
     /* Check safe address list. */
     $safeAddrs = $injector->getInstance('IMP_Prefs_Special_ImageReplacement')->safeAddrList();
     foreach ($from as $val) {
         if ($safeAddrs->contains($val)) {
             return true;
         }
     }
     return false;
 }