Newbie here switching everything over from ST. Can't get the SMS to work. Have tried +1, without it, no SMS delivered to my phone. Any ideas what I might be doing wrong?
I had same issues that sometimes would work and sometimes not. Using the pushover android app (HE recommends this also) solves this as all notifications happen instant, and you don't risk the NOT getting notifications because you're over your 10 messages per day limit.
I use Android Pushover as suggested by @waynespringer79 - well worth the price (~$5 if I'm remembering correctly). I also use Alexa-TTS to speak specific notifications - directed to specific Echos dependent on where I'm at.
There is also a driver for doing email notifications through a "man-in-the-middle" implementation. I use that via email-to-sms which every carrier has. I've used it and it works really well.