[aiharkness]

In addition to the above, the hosted email account (i.e. the @carrier.blackberry.net address) is tied to your service provider. When you change carriers, you lose the account you had with the first carrier, and you'll have to create another, new, address with the new carrier.

Your other email, like google, yahoo, your ISP, whatever, you'll be able to set those up with the new service just like you did before with the pervious service.

Also, the emails on the device will disappear when the service books from the old carrier are removed, which I'm guessing will happen automatically when you activate the new data service. My advice is take measures ahead of time to save the information you need, before you cancel the service you have now.