Every mobile provider is tightening down their spam algorithms. Maybe it gets going for awhile, but then it quits. You can confirm this by looking in your email sent folder and seeing they sent, so at that point it is your mobile provider.
Most of us have quit using SMS for this reason.
Either get the BI app to receive push notifications ($10) or do what most of us have done and get the pushover app ($5). The advantage to the pushover app is you will get pictures when away from your home. With the BI app, you will only get pictures with the push if you forward ports or have an ongoing VPN connection back to your system.