fixes MicrosoftDocs/azure-docs#18823

Author: tfitzmac

articles/event-grid/compare-messaging-services.md

@@ -51,6 +51,8 @@ Event Grid is an eventing backplane that enables event-driven, reactive programm
 
 Event Grid is deeply integrated with Azure services and can be integrated with third-party services. It simplifies event consumption and lowers costs by eliminating the need for constant polling. Event Grid efficiently and reliably routes events from Azure and non-Azure resources. It distributes the events to registered subscriber endpoints. The event message has the information you need to react to changes in services and applications. Event Grid isn't a data pipeline, and doesn't deliver the actual object that was updated.
 
+Event Grid supports dead-lettering for events that aren't delivered to an endpoint.
+
 It has the following characteristics:
 
 * dynamically scalable