Unless things have drastically changed, you probably won't get your own email address at TBS. I didn't get mine until I showed up to the FRS. However, with a little legwork, you might be able to set yours up ahead of time. The only catch is you can only access it from NMCI machines.
The first step is to get a NMCI username. Your PTAD OIC/SNCOIC should be able to point you in the right direction on this one. After you have that, and are able to log into an NMCI computer (preferably using your CAC card vice username/password), you need to be put on the Global Address List, or GAL. There's some request form you'll need to fill out to be processed by the local AISD or Comm shop. A few days later, you'll need to call the NMCI Help Desk (a toll-free number that's usually on the service tags on NMCI machines). Navigate the menu to account/password activation. Tell the tech, plain English, what you're trying to do. You'll need a registered verifier (someone who set up themselves with a password to tell the tech that you're legit) to finish the conversation with the tech. To check if this is successful, have someone who is already set up with their account search for your name in the contacts list. If both are successful, in theory, you should be able to log on to a machine, open up Outlook, and viola, there's your email.
I'm only a budding S-6, and this is what I remember from when I set my account up, so it may not (correction: probably won't) work for you, but might set you in the right direction.