Developing a Remote Transport Provider

Some client applications benefit from having a transport provider with remote capabilities, including:

• Clients whose underlying messaging systems are slow.
• Clients with low bandwidth connections to their messaging servers.
• Clients with intermittant connections to messaging systems or networks.
• Clients that must, for whatever reasons, minimize the time spent connected to their message servers.

The most common situation where remote transport providers are used is when a client's connection to the messaging server is over a modem (low bandwidth) or is connected through a long-distance telephone call.

MAPI provides a definition of a remote interface that transport providers implement in order to satisfy clients' needs in these circumstances. That interface is the IMAPIFolder interface, which enables a user to preview the contents of the messaging server without downloading entire messages or folders. This is the same interface that message store providers implement. By having a transport provider implement a special MAPI folder, it can provide access to messaging systems with special connection requirements.

The topics in this section describe the remote transport architecture and provide information for implementing a remote transport provider.