Sending a message is not the same as delivering it. Email and SMS providers report back what happened, and we keep that against the alert.
That turns an invisible problem into a visible one. A mistyped phone number produces years of alerts that were sent perfectly and arrived nowhere, and nobody finds out — the person doesn't know what they didn't receive.
- Alert history shows the delivery status per recipient per message.
- Readiness lists contacts that have failed in the last 30 days as a critical finding.
- The usual causes are a typo, a disconnected number, or a corporate mail filter.
After correcting a contact, send a test alert. That closes the loop rather than assuming it's fixed.