Introduction to Transport Agents
Microsoft Exchange Server 2010 provides a library of classes that support the extension of Exchange transport behavior. You can use these classes to extend and modify transport behavior to customize acceptance, rejection, routing, and delivery of messages and to convert between various types of content.
The Microsoft.Exchange.Data.Transport namespace contains types that support the extension of transport behavior in Exchange 2010. You can use the types in this namespace to specify how the Exchange 2010 transport handles messages by implementing transport agents that act on SMTP, routing, and delivery events. For more information about implementing agents, see Working with Exchange Transport Agents. Exchange 2010 introduces the Microsoft.Exchange.Data.Transport.Delivery namespace, which contains types that enable you to implement transport agents that respond to transport delivery events. By using delivery agents, you can define routed connectors that use custom delivery types and deliver messages to those connectors.
Content Conversion Namespaces
The Microsoft.Exchange.Data.ContentTypes.iCalendar, Microsoft.Exchange.Data.ContentTypes.Tnef, Microsoft.Exchange.Data.ContentTypes.vCard, and Microsoft.Exchange.Data.Mime namespaces contain types that support converting from and to various content types that are commonly found in e-mail messages. You can use the classes in these namespaces to read, write, and modify e-mail message content types such as iCalendar, TNEF, vCard, and MIME formatted content. Exchange 2010 includes a new namespace, Microsoft.Exchange.Data.ContentTypes.vCard, that contains types that enable you to read and write contact information by using the vCard format. You can use the types in the Microsoft.Exchange.Data.ContentTypes.vCard namespace in transport agents to perform actions on messages such as reading and writing contact information as vCard attachments.