SMS fallback automatically sends an SMS message when the initial message cannot be delivered via the original channel under specified conditions and within a set time. This feature enhances message delivery rates and ensures that critical, time-sensitive notifications, such as one-time passwords (OTPs) or deadline reminders, arrive on time.
Before you begin
Activate Chat App Message Service.
Activate Short Message Service (SMS).
Register a Sender ID in SMS.
Procedure
Configure fallback settings and enable the feature
Log on to the Chat App Message Service console.
Add a fallback rule. For detailed instructions, see Fallback rule.
Add a fallback policy. For detailed instructions, see Fallback policy.
In the left navigation pane, choose Channel Management and select the Channel ID for which you want to enable SMS fallback.
Only WhatsApp and Viber channels support SMS fallback.
Choose Service Settings in the left navigation tree.
Enable the Activate SMS switch.
You must turn on this switch to use SMS fallback.
Configure SMS fallback when sending messages
In the left navigation pane, choose Channel Management and select the Channel ID you want to use.
On the channel details page, choose Message Sending.
Select the desired language, template, send account, and send type.
From the Fallback Policy drop-down list, select a policy.
Select the Fallback Trigger.
Undelivered: The message was not delivered.
Unread: The message was delivered but not read.
Send Failed: The message sending process failed.
Configure the Fallback Message Content.
Set the Fallback Duration, measured in seconds. The fallback is triggered if this specified time elapses and the system has not yet received a status report that meets the fallback trigger condition. The duration must be between 60 and 43,200 seconds.
If you leave this field empty, the fallback is triggered only after the system receives the corresponding status report. For example, if you set the trigger to Unread and leave the duration empty, the system triggers the fallback only after receiving a status report confirming the message is unread.
You may be charged twice if a status report is received after the fallback has already been triggered. For example, you configure an SMS fallback for a WhatsApp message with the following settings:
Fallback Trigger: Undelivered
Fallback Duration: 60 seconds
Then, if no Delivered status report has been received after 60 seconds, the system triggers the SMS fallback and sends the fallback message. At the 80-second mark, the Delivered status report for the original WhatsApp message arrives. In this case, you are billed for both the WhatsApp message and the fallback SMS message.
Select the Import Method for recipient numbers.
Click Send to send the message.