---
schema_version: "1"
id: e6d57302d454703b3887fc8701dc5fe16642776d30e3593a0d08e93057dc9dbe
title: Retries and Callback Suspensions
collection: developer
version: current
locale: en-us
portal_url: https://docs.salesforce.com/developer/current/en-us/marketing-cloud/guides/mc-apis/ens-retries-suspensions.md
canonical_url: https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/ens-retries-suspensions.html
source_site: developer.salesforce.com
content_type: documentation
content_hash: d53e4a86f00ddebfb3aa5e2b2d7dc9ce72275257cdb66610a9cdc7dc8f67a151
products:
  - Marketing Cloud Engagement APIs and Programmatic Languages
  - Marketing Cloud
---
# Retries and Callback Suspensions

Your Event Notification Service (ENS) callback has up to three seconds to process an event batch and return an HTTP 200, 201, 202, 203, or 204 response, indicating successful processing.

If the callback times out, is unavailable or unreachable, or returns an error code, the ENS tries to send the batch up to three times.

If the third attempt fails, the batch is deferred for up to 10 minutes, and the ENS tries to deliver the delayed events at decreasing intervals for up to seven days. After that, retries stop and delivery fails.

For deactivated subscriptions or callbacks, the ENS doesn’t attempt redelivery.