If you have configured a trigger, escalation or SLA to send SMS alerts, but agents are not receiving them, check all of these possible causes:
1. The agent does not have a valid cellular/mobile phone number set up in their profile. This must be added either through Admin > Agents or through the agent's Preferences, but not through the agent CRM app.
2. The automation did not run when you expected (for example, because of a mistake in the criteria). Check the Full Log for an affected ticket to see if/when it ran.
3. There is a problem with your account with the SMS provider - for example, you have exceeded the allowed number of messages or a subscription payment has not been received.
4. Cellular service providers do not guarantee SMS delivery and may occasionally fail to deliver an SMS message altogether.