SMS Notification Error: [569] Destination address suspended by carrier

Problem

xMatters logs the following error when sending an SMS notification: 

DELIVERY_FAILURE; [569] Destination address suspended by carrier

Environment

All versions of xMatters

Resolution 

This is due to a suspension implemented by your SMS or mobile carrier. We recommend contacting your carrier to determine why this is happening and how to resolve it.

Causes

• The SMS or mobile carrier has suspended the number.
• The number was not ported correctly when switching between carriers.