Chris is asking a nice question. With great minds who program sockets and
whatnot I'm hoping that SOMEONE has an IBM i based project they wrote in
house to do SMS texting which doesn't require an email gateway.
As Chris said, email gateway's require knowing the carrier. And, as
someone else said, some email gateways limit the number of emails to text
stuff. I have ran into this myself. It was x/month and then charged
through the nose.