An inbound message has two distinct stages: received and delivered or undelivered.
1. Received
Plivo receives an inbound message from a carrier. The user is charged for this message. If the message_url or message_method is not configured in the user's application to the number that receives the message, the message remains marked as "received."
2. Delivered/Undelivered
Once Plivo receives a message, it sends a callback with message attributes to the message_url. Based on the response received, the message is categorized as either delivered or undelivered.
- Delivered: After a successful callback to the message_url, the message status is set to "delivered."
- Undelivered: The message_url is invalid, inactive, or not responding. Plivo will retry callbacks for the next 24 hours. If all callback attempts fail, the message status will be set to "undelivered."