Is there any way to set up a follow up e-mail that sends automatically based on a time delay if an order is not validated ?

eyestrain, would you please explain what you mean by
" if an order is not validated " ?

If an order does not get Validated by Paypal / Worldpay / Google Checkout because the person buying has not completed.
 
This can be because of browser security setting or just they are trying the cart out... I always follow up with an email.
 
However It would be handy if New Order is showing against the Order that a time lagged email can be set up to automatically send.

The only feature for this seems to be Orders Recover [Order drop down menu] - it is not automatic as you ask, but I use it every morning to e-mail out to all Unpaid Orders from the previous day.
 
You can edit the message going out.
 
Chris