Delivery Receipt (DLR) | SMS – PUSHTech Help

A delivery receipt (DLR), is a piece of information sent over the mobile network to the original sender of a message. This packet of information contains the delivery status of the message, whether it was successfully delivered or if the delivery failed. This makes delivery receipts invaluable in determining the status of your messages, as delivery receipts allow you to verify whether your SMS has been received at the destination phone.

1.1 - What are the most common delivery receipt status?

Status	Description
Delivered	The message has been received at the destination phone and the operators have provided the information.
Sent	The message has been delivered to the carriers by our CRM, and our CRM is awaiting confirmation of message delivery from the relevant carrier.
Undelivered	After trying for a period of time, the operator was unable to deliver the message to the destination phone. Possibly caused by an invalid sender ID. Confirm that the number is correct, that the phone is turned on and within reception range, and try again later or and within reception range, and try again later or with a different sender ID.
Invalid Number	The destination number is invalid and our system cannot recognize it for delivery. Common causes: the number is not in international format, entered incorrectly or is too short/long.
Rejected	The message was successfully sent to the carrier for delivery, but was actively rejected. This is usually related to problems with an invalid sender ID in the destination network.
Expired	In the event that a mobile device is not reached, delivery will be reattempted for a period of time. Once the maximum retry period has been reached for the network to which the message is delivered, the status will be marked as expired and delivery will no longer be reattempted.
No Credits	Your account is out of credits. Buy more credits and send them again, or resend these messages from your outgoing message report.

1.2 - How DLR works?

SMS messages are sent to network elements called Short Message Service Central (SMSC), which are responsible for final delivery to destination phones. When our CRM sends messages for delivery, they are sent with a delivery confirmation request for that message (when available).

Once a message has been sent to the SMSC, delivery is attempted. If delivery is successful, the message will be received and the SMSC will return a delivery receipt to our CRM, confirming that delivery was successful. When delivery of the message is not immediately successful, the SMSC will temporarily store the message and reattempt delivery for a maximum period of time. In the event of a permanent failure, a delivery receipt will be sent to our CRM indicating that the message could not be delivered.

The availability of delivery receipts depends on whether the destination network supports them. Our CRMS relies on this delivery information to be sent by itself. Therefore, our CRM cannot guarantee that delivery receipts will be available for all destinations.

1.3 - How can I view delivery receipts?

Delivery receipts are used to update message status within your Outbound Report.

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