Hi, use webhooks to get event data and subscribed to `event:klaviyo.received_email`. Starting 2025-09-02, we stopped getting webhook deliveries for a subset of our connected accounts.
When we check the status of the webhook using the API, it says enabled. We also did not see a corresponding increase in non-2xx response from our servers to the webhook urls that would indicate klaviyo may be in backoff or may have disabled the webhook.
Patching the webhook using the API seems to have got them unstuck but we are unsure of what happened and if it might happen again.
Best answer by Timmy Solomon
Thanks for sharing this. A few things you might want to check:
Sometimes Klaviyo pauses or slows down webhooks if they see a number of failed (non-2xx) responses, even for a short time. Patching them through the API can “unstick” them, which sounds like what you saw.
Even if the webhook shows as enabled, certain event types (like klaviyo.received_email) might stop if there were account or API changes. Worth checking if Klaviyo made updates around Sept 2.
Some systems keep a small queue of failed events and drop them if retries run out. You may want to confirm with support if Klaviyo does this.
As a safety net, you could add a quick monitor so if no events come in after X minutes, it auto-refreshes the webhook.
Since the patch worked, it feels like Klaviyo may have temporarily put them on hold. Best bet is to share timestamps and account IDs with support so they can confirm.
Thanks for sharing this. A few things you might want to check:
Sometimes Klaviyo pauses or slows down webhooks if they see a number of failed (non-2xx) responses, even for a short time. Patching them through the API can “unstick” them, which sounds like what you saw.
Even if the webhook shows as enabled, certain event types (like klaviyo.received_email) might stop if there were account or API changes. Worth checking if Klaviyo made updates around Sept 2.
Some systems keep a small queue of failed events and drop them if retries run out. You may want to confirm with support if Klaviyo does this.
As a safety net, you could add a quick monitor so if no events come in after X minutes, it auto-refreshes the webhook.
Since the patch worked, it feels like Klaviyo may have temporarily put them on hold. Best bet is to share timestamps and account IDs with support so they can confirm.
Are you seeing a certain pattern in the error messages you’re receiving? Are you getting 4xx or 5xx errors, and is there a certain specific error code you ran into most often? If you have this info, let me know, and I can look into it.
