Sending may fail in below situations and the SMS will NOT be sent:
SMS service is not enabled for the organisation (consult FAE)
SIM IDs provided do not belong to the organisation
SIM ID duplicates
SMS sending via API is not supported for some SIMs
Idempotence
If same nonce, same sim_ids and the same sms message is sent in 2 requests within 10s, they will be treated as the same request, and the same job id will be returned. The actual sending will only occur once.
When a request is timeout, you may use above method to retrieve the job id.
Otherwise, it will be treated as a new request and the sms will be sent again.
Result
Response of this API indicates the receipt of the request only. It does not indicate the status of sending of the SMS.