Am I charged for messages that have not been delivered?
Unfortunately yes, because the responsibility of message delivery belongs to the associated network operators to whom your MT SMS are submitted to and our costs are incurred upon message submission.
To further explain, we format our users' MT SMS (according to the relevant protocols and standards) and then submit them to network operators. Once this submission has taken place, the network operator takes on the responsibility of message delivery and there are many different reasons why a message may not be delivered (e.g. the recipient is on the network's black list).
However: