public function close()
{
$this->setError('');
$this->server_caps = null;
$this->helo_rply = null;
if (is_resource($this->smtp_conn)) {
// close the connection and cleanup
fclose($this->smtp_conn);
$this->smtp_conn = null;
//Makes for cleaner serialization
$this->edebug('Connection: closed', self::DEBUG_CONNECTION);
}
}