AWS Pinpoint seems to be sending multiple copies of the same SMS (though API was called just once)

Hello Sudip,

I understand that you have noticed Pinpoint sending duplicate SMS messages to some users, even though API was called only once.

Pinpoint service does not send multiple copies of same SMS message. Pinpoint SMS service, instead, relays messages to downstream provider and phone carrier. In oder to investigate this issue, we need to troubleshoot based on your specific scenario. Since we cannot discuss account specific troubleshooting on re:Post, we suggest to reach out to AWS Support with specific details, including message ids and timestamp of duplicate messages.