How long does Vonage retry inbound messages on the Messages and Dispatch APIs?
- SMS API
- Messages API
- Dispatch API
- Callback Retry
Your handler must return a 200 status code to avoid unnecessary callback queuing. Customer webhooks that respond with HTTP 429 or HTTP 5xx response will be attempted again by Vonage. Each inbound event/message is treated and retried individually (no queueing per API Key, for example). It is an exponential backoff that retried initially after 5 seconds, and the delay doubles on every retry until it reaches 15 minutes and then keeps that frequency. After 24 hours, the messages are discarded.