code: public static function listAddresses($list = array(), $type = 'to')
      {
          if (empty($list)) {
              return;
          }
          $str = ucfirst(strtolower($type)).': '.self::mailListTagger($list);
          return(trim($str, Mailer::$ADDERSSES_SEPARATOR).Mailer::$LINE_ENDING);
      }
docs: Build a list of name=>email pairs compliant to RFC2822
  
  @param array $list A list of name=>email pairs
  @param string $type The type of the field
  @return string The generated list