GMS offers a fallback option for your messaging campaigns: you can set up preferred backup channels and their hierarchy (see the example below) to create a complex messaging chain solution.
![](https://developers-test.gms-worldwide.com/wp-content/uploads/2023/03/What-happens-if-a-Viber-Business-Message-is-not-delivered.png)
GMS offers a fallback option for your messaging campaigns: you can set up preferred backup channels and their hierarchy (see the example below) to create a complex messaging chain solution.