Is There a Gap in Your Mass Notification System Plan?
Check with your cell providers to make sure they aren’t blocking your SMS/text alerts.
It appears that major, regional and independent carriers (like Sprint, Verizon, regional carriers and pre-paid providers), appear to be flagging mass notification messages as potential spam, or “alert” (short code) messages, and either disabling (blocking), delaying or denying SMS/text transmissions to some or all of their cellular subscribers. These are the folks who are subscribing to your mass warning alert messaging system.