The class is the base class from which all transport agents derive.
Assembly: Microsoft.Exchange.Data.Transport (in Microsoft.Exchange.Data.Transport.dll)
Transport agents have full access to all e-mail messages that they encounter. Exchange puts no restrictions on a transport agent's behavior. Transport agents that are unstable or contain security flaws may affect the stability and security of Exchange. Therefore, you must only install transport agents that you fully trust and that have been fully tested in a test environment.