Technical
Delivery and read receipts
Status callbacks telling you a message was sent, delivered, read — or failed, with a reason code.
Technical
Every message moves through statuses reported back by webhook. The useful one is failure: Meta returns an error code that distinguishes a temporarily unreachable handset from an invalid number from a policy block.
That distinction is what makes automatic retries safe. Retrying a transient failure is sensible; retrying a hard failure damages nothing but wastes money and tells you nothing.
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