FYI, dunno if this had been mention before, now you can log in to tmobile.com, delete the blackberry email address, and pick a new one without calling customer service and the whole nine yard.
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.T...Mobile. BB 8220
OS v4.6.0.180 DM v4.2.2.14 SP2
I have been doing this for a while, actually ever since I have had the BlackBerry (a little over 1 year). I never had to call them to change that address.