We constantly monitor our sending rates and deliveries to the mobile carriers to provide our customers with the absolute best delivery.
When messages are sent from our service we push them straight to the mobile carrier and then the carrier does the final delivery to the handset. We do not control final delivery, they do.
Below are the most popular reasons why a message does not reach its final destination:
Bad Signal - The end user was sitting on an airplane, or maybe a subway, maybe they're up in the mountains. You get the idea.
Account Issue - There could be an issue with the end users account or it could be temporarily suspended for a certain reason.
Number Block - Most carriers and handsets today allow consumers to block getting messages from any number. Some make it as simple as a click to block on their phone.