code: public static function formatText($txt = '', $type = 'plain', $spaces = false)
      {
          switch ($type) {
              case 'ascii' :
                  $_txt = '';
                  if ($spaces==true) {
                      $txt = str_replace(' ', '_', $txt);
                  }
                  for ($i=0; $i<strlen($txt);$i++) {
                      $_txt .= self::charAscii($txt[$i]);
                  }
                  $txt = $_txt;
                  break;
              default : break;
          }
  
          $mailer = Mailer::getInstance();
          $limit = $mailer->getOption('wordwrap_limit');
          $formated='';
          foreach (explode("\n", $txt) as $_line) {
              $_line = trim($_line);
              if (strlen($_line)>$limit) {
                  $_line = wordwrap($_line, $limit, Mailer::$LINE_ENDING);
              }
              if (strlen($_line)) {
                  $formated .= $_line.Mailer::$LINE_ENDING;
              }
          }
          return $formated;
      }
docs: Format a text with a special encoding
  
  @param string $txt The text to format
  @param string $type The type of the encoding : 'plain' or 'ascii'
  @param bool $spaces Replace all spaces with underscores or not (default is FALSE)
  @return string The transformed text