Your outbound message could be listed as queued, sent, failed, delivered, or undelivered.
- All outbound messages are initially queued as system accepts the message and attempts to send it to a carrier.
- A message is marked as failed if an internal error occurs before the message is passed on to downstream carriers. Users are not charged for failed messages.
- A message is marked as sent when the message is successfully passed on to a downstream carrier. Users are charged for sent messages.
- A message is marked delivered or undelivered based on the delivery receipt received from the carrier. Users are charged for these messages.
Note that delivery receipts are not universally supported across countries, number types, or mobile networks. The final status of a message may remain “sent” in cases where delivery receipts are not received. It's always good to consider sent + delivered as delivered.