Reggie.
I too have a Zonealarm Firewall and that was no problem to the
CBFSMS website. However, the Pop-up Blocker from Google temporarily stopped their pop-ups, but you can temporarily allow that site for the duration of the use of the services. You have a couple of tick boxes that you
MUST fill in to be able to send, but they're only a minor irritation.
Very useful if you have a friend that doesn't have a TEXT facility on their phone & they want to get hold of you from overseas. NO additional charges & a bit more immediate than an email.