---
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title: Get Started with Event Notification Service
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locale: en-us
portal_url: https://docs.salesforce.com/admin/current/en-us/mktg/264-0-0/mc_overview_ens_get_started.md
canonical_url: https://help.salesforce.com/s/articleView?id=mktg.mc_overview_ens_get_started.htm&release=264.0.0&type=5
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description: Configure your system to work with the Event Notification Service (ENS) in Marketing Cloud Engagement. The configuration process registers the callbacks and creates the subscriptions used to interact with your external system.
products:
  - Marketing
  - Marketing Cloud Engagement
release: "264"
---
# Get Started with Event Notification Service

Configure your system to work with the Event Notification Service (ENS) in Marketing Cloud Engagement. The configuration process registers the callbacks and creates the subscriptions used to interact with your external system.

You must configure your own external system to receive and confirm callback and subscriptions. Engagement isn’t responsible for developing this system to work with ENS.

Review the process outlined in [Event Notification Service Activities](https://developer.salesforce.com/docs/marketing/marketing-cloud/guide/ens-activities.html) on Salesforce Developers for an overall understanding of the process. The callbacks and subscriptions you create replace the API calls in the process, but otherwise the process is similar. Your external system works with Engagement to verify and process your callbacks and subscriptions.

Salesforce Developers provides additional information on notification signing, retries, and callback suspensions. Include these factors when you plan your external system implementation.

1. Supply an HTTPS callback URL, also known as a webhook, for your application. HTTP isn’t supported for callback URLs.
2. Register and verify your callback URL.
3. Create a subscription that requests notification events. A subscription indicates which event types to receive notifications for and which callback, or webhook, to receive them on.
4. Prepare your system for the possibility of receiving a notification event multiple times because the ENS is an "at least once" delivery system.
5. To stop receiving notifications, you can pause a subscription at any time. When you unpause the subscription, only new event notifications are delivered. Notification events that occurred during the pause are dropped.