Turn off your data and disconnect from wifi, then try again. I believe that will force it to send via SMS. You might need to go through your client's app settings.

The Google Android client is nice because it displays what protocol it is sending over. It is important to confirm that it is sent over SMS. Also, it is important that the words "secure communication" are sent in all lower case which I see that you did.

Thank you for taking the time to test this. If you are sure it is being sent over SMS then I will add your entry as an example where it can be both sent and received