DLRPost
From SMS Wiki
How to Get Message Delivery Confirmations Using HTTP-POST
You need to implement HTTP-POST handler that will listen to incoming HTTP-PUSH from our service. This will look similar to:
name = your_username trackingid = MTID119946997360917165 status = DELIVRD recipient = 12088580767
For example, assuming that your application is at domain foo.com the call we make is
Note: https is also supported.
When you send a message (using Send_Plain, for example) you will receive MTID (message or tracking id). This is a unique number assigned to each message. You will need to store it. When you get incoming HTTP-PUSH, simply query your database to find matching tracking_id. When you find it, update status of message