Okay - so I have an iPhone in the US - I don't think I need to name my cell
phone provider by name

I phoned today to add international calling on the phone (apparently you
can't just make international calls without adding that), and in the process
I asked "what's the email address for my cell phone?"

Rep: Well, the email address we have for your account is danita at
caledonia dot net
Me: No - I mean the email address that you send to to send an SMS to the
Rep: I don't know what you mean
Me: My TMobile address was number@tmomail.net, and in fact that allowed me
to have nameofmychoice@tmomail.net, and when someone sends an email to that
address it would come to my phone as an SMS.
Rep: well, we have down that this is danita at caledonia dot net
Me: How would that be delivered to my phone?
Rep: Well, you'd have to talk to your provider like Yahoo or whatever to
see how they do that
Me: Nevermind - have a nice day

I googled it - it's number@txt.att.net - but not only didn't the "main"
support guy know this, neither did the international services guy that I got
on the phone after that!