The delivery reports indicate the status of the messages you submitted. The delivery reports can be thought of as electronic signatures, informing the sender about the status of the message. The DLR removes the guesses after you have sent your messages, giving you the accurate picture of the status of the messages sent.
It is EASY, RELIABLE, AND COST-EFFECTIVE. Not all companies have the technologies and the resources to provide such reports, but we offer you this facility.
The SMS was successfully sent from your end to the customer's side but is yet to reach the recipient's operator end due to either unreachable, switched off number, or bad network coverage at the time sent
This shows when the recipient's number is opted in for DND / Do Not Disturb service. DND active numbers do not receive promotional SMS.
This shows that the server tried to push the SMS to the recipient's phone but was unable to. Hence, after multiple tries the status changes to this. It could be possible that the recipient's number was incorrect.