A functioning digital messaging architecture requires connectivity, a processing container, and routing logic. First, each external messaging platform must be connected to Dynamics 365 Contact Center through its supported channel configuration or connector. For custom platforms, Microsoft requires registering the messaging channel and configuring the integration endpoint or Messaging API connection.

Second, the channel must be associated with a messaging workstream. A workstream defines how incoming work is classified and distributed and provides the operational context for queues, assignment, capacity, and channel-specific behavior. Microsoft explicitly requires a messaging workstream when configuring custom messaging channels.

Third, routing rules determine the destination queue for each incoming interaction. Route-to-queue rules evaluate configured conditions and send the work item to the matching queue, with the workstream fallback queue used when no rule matches.

Session templates affect the CSR workspace after assignment and are not required to enable message ingestion and routing. An asynchronous messaging policy is likewise not one of the foundational steps listed for enabling each digital channel.

The uploaded material confirms A, D, E.

Study Guide reference: Implement channels - > Configure digital messaging channels, connectors, workstreams, and routing.