Hi,
The easier would be to edit the paypal plugin (paypal.php file) and find the line
$email->body = str_replace('<br/>',"\r\n",JText::sprintf('NOTIFICATION_REFUSED_NO_CONNECTION','Paypal'))."\r\n\r\n".JText::sprintf('CHECK_DOCUMENTATION',HIKASHOP_HELPURL.'payment-paypal-error#connection') . $order_text;
And replace the line just below
$this->modifyOrder($action, null, null, $email);
By
// $this->modifyOrder($action, null, null, $email);
By commenting that line, the specific email won't be send anymore.
And you need to only comment that line for the "NOTIFICATION_REFUSED_NO_CONNECTION" case.
Regards,