If you receive an error message and your text was not delivered, hover over the red error to view what might have happened. Here are a few errors that you might have received.
30003 : Message Delivery - Unreachable destination handset : The destination carrier reports the “To” number is unreachable, the device is likely powered down, out of the service area, or may not accept your message.
30004 : Message Delivery - Message blocked : Your message has been blocked from reaching the destination by carrier.
30005 : Message Delivery - Unknown destination handset : The destination carrier is reporting the To number is unknown, or no longer in service.
30006 : Message Delivery - Landline or unreachable carrier : The destination is a landline phone, or the destination carrier can’t be reached.
30007 : Message Delivery - Carrier Violation : The destination carrier is filtering out your messages.
30008 : Message Delivery - Unknown error : The destination carrier has returned an undefined error message.
Read this article to learn How to avoid carrier filtering