This is a reply i got when i asked about this same inquiry "it is a free trial anywhere there is no branded carrier offering. if a carrier in your area starts offering an Ovi Push email offering, your trial no longer works, and you'll need to get it from the carrier"
What happens after the trial? As your trial nears its end, we will send you a reminder. If you do not want to purchase a subscription, simply allow the trial period to end. We will notify you when the period ends, and we will cancel your Nokia Messaging account. You will not be billed for the service and you will not have to do anything. Enjoy your mobile email!