Thanks for your help. I checked all that you suggested and everything looked OK. Determined it must be something with my custom alert. Tinkered with the Customized Content, with no luck. Created a new Custom Content and updated my program to reference the new one, and it works! Not sure why or what was different. Thanks for steering me to a successful conclusion.
Just installed 3 door sensors. Can track status on/off via admin console. But, my program to send alerts doesn't work. my program tests Control of sensor equal to ON, if true then send alert. But, not working. Any ideas?