It only connects with the transport service on a mailbox server and does not backlog any messages locally
Front end transport service: It does basic message filtering based on domains, connectors, senders and recipients.Transport pipeline is made up of three different services: Explain what are the important features of Transport Pipeline?.When a database fails over, it also fails access to the mailbox.For given mailbox, it provides all core exchange functionality.Handle connectivity as clients don’t connect directly to the mailbox services.Provide messaging records management and retention policies.Provide high availability and site resiliency.Mention what is the role of Mailbox server?.Allows the use of layer 4 (TCP affinity) routing.Routes requests to the correct mailbox server.Handles all client requests for Exchange.Gives unified namespace, network security and authentication.