code: function AddrAppend($type, $addr) {
          $addr_str = $type . ": ";
          $addr_str .= $this->AddrFormat($addr[0]);
          if(count($addr) > 1)
          {
              for($i = 1; $i < count($addr); $i++)
                  $addr_str .= ", " . $this->AddrFormat($addr[$i]);
          }
          $addr_str .= $this->LE;
  
          return $addr_str;
      }
docs: Creates recipient headers.
  @access private
  @return string