image tag that triggers an email confirmation message

we need to have an email confirmation sent out when a prospect hits the confirmation page. example: Sale order page (this is not our site this is 3rd party our clients site) Confirmation page after sale is completed -we would like to have our client place an image tag or other method, that would send an email confirmation to the buyer. -this confirmation page will have a unique confirmation number from our pool of numbers Here is a little outline <[login to view URL]>