Isn't the easiest solution to just build a Faraday cage around the prison? ;)
Unless there's a worry that the "users" may be able to tap into it, wired is the way to go. Any wireless solution would be unwieldy or nonstandard, or both.
TDP is, unfortunately, a load of baloney. Intel's seem more honest but considerably more useless; their TDPs are basically what the cooling solution needs to dissipate for the chip to only hit the base clock. AMD's TDPs are supposedly what the cooling solution needs to dissipate for the...
I'm guessing that you're dead already, then.
You may want to check if Gmail will fetch the mail for you. I haven't set it to up with any other accounts since the days of POP, so I don't know what it supports now.