Event Notification Service
Use the Event Notification Service (ENS) API to receive notifications when certain events occur. You can be notified when customers request password resets, get order confirmations, log in using two-factor authentication, and other events.
Example: Northern Trail Outfitters, or NTO, requests that Marketing Cloud Engagement send an online order confirmation email to a customer. The customer’s email address isn’t valid, so the ENS notifies NTO almost immediately that the order confirmation bounced. Using that feedback, NTO’s system sends the customer the order confirmation via SMS instead.