Add delivery detail

Author: baanders

articles/digital-twins/concepts-data-ingress-egress.md

@@ -46,6 +46,8 @@ There are many other services where you may want to ultimately direct your data,
 
 For example, if you're also using Azure Maps and want to correlate location with your Azure Digital Twins graph, you can use Azure Functions with Event Grid to establish communication between all the services in your deployment. For more information on integrating Azure Maps, see [Use Azure Digital Twins to update an Azure Maps indoor map](how-to-integrate-maps.md). For information on routing data in a similar way to Time Series Insights, see [Integrate with Time Series Insights](how-to-integrate-time-series-insights.md).
 
+Azure Digital Twins implements **at least once** delivery for data emitted to egress services. 
+
 ## Next steps
 
 Learn more about endpoints and routing events to external services:

articles/digital-twins/concepts-route-events.md

@@ -31,6 +31,8 @@ Event routes are used for both of these scenarios.
 
 An event route lets you send event data from digital twins in Azure Digital Twins to custom-defined endpoints in your subscriptions. Three Azure services are currently supported for endpoints: [Event Hubs](../event-hubs/event-hubs-about.md), [Event Grid](../event-grid/overview.md), and [Service Bus](../service-bus-messaging/service-bus-messaging-overview.md). Each of these Azure services can be connected to other services and acts as the middleman, sending data along to final destinations such as TSI or Azure Maps for whatever processing you need.
 
+Azure Digital Twins implements **at least once** delivery for data emitted to egress services. 
+
 The following diagram illustrates the flow of event data through a larger IoT solution with an Azure Digital Twins aspect:
 
 :::image type="content" source="media/concepts-route-events/routing-workflow.png" alt-text="Diagram of Azure Digital Twins routing data through endpoints to several downstream services." border="false":::