Delayed event logs for Pinpoint SMS sent to South Africa

Hi, regarding the delivery of SMS messages through Amazon Pinpoint, it's important to understand the nature of the service as a distributed system. Event logs related to SMS delivery can vary significantly in the time it takes to be received back by AWS, depending on factors such as the target country and the carrier involved.

Specifically, SMS events generated by carriers can take up to 72 hours to be received by Amazon Pinpoint. This delay is due to the complexities involved in the carrier networks and the asynchronous nature of SMS delivery. Therefore, the event logs should not be used as an immediate indicator of whether an outbound message has been successfully delivered or not.

If Amazon Pinpoint does not receive a final event from a carrier within 72 hours, the service will automatically assign an "UNKNOWN" record_status to that particular message. This status indicates that the service is unable to determine the final outcome of the message delivery, as it has not received any confirmation or failure notification from the carrier.

It's important to note that the 72-hour window is a maximum time frame, and in many cases, the event logs may be received later than that, not sooner, like you are seeing with countries like the UK, Canada, and Portugal. However, to ensure accurate tracking and reporting, Amazon Pinpoint recommends waiting for the full 72 hours before considering a message delivery as unknown or failed.

For more detailed information, please refer to the official Amazon Pinpoint documentation on SMS event streams: https://docs.aws.amazon.com/pinpoint/latest/developerguide/event-streams-data-sms.html