The failure mode this prevents is specific and bad: on the hottest afternoon of the year, a regional manager's phone receives forty separate messages, so they stop reading any of them — on precisely the day the messages matter most.
So delivery is counted per recipient. Once someone has been sent about five alerts inside a thirty-minute window, additional ones are grouped into a single summary message naming the stores involved, rather than sent one by one.
- Nothing is discarded. Every alert still exists in alert history, and every store's reading is still recorded.
- Rollup applies to notification volume only. It does not slow escalation and does not affect acknowledgment.
- If the counting itself fails for any reason, the alert is sent individually. The system fails toward telling you.