When messages are sent to recipients whose addresses fall into a designated address space handled by a gateway, the message transfer agent (MTA) routes the mail to the MTS-Out folder of a gateway handling that address space based upon information in the Gateway Address Routing Table (GWART). If a recipient’s address is not handled by any gateway, the message is undelivered. To a MAPI application, a Mail-Gateway object appears as a regular mailbox, where MTS-OUT is used instead of Inbox and MTS-IN is used instead of Outbox.
A Mail-Gateway object in the directory is not accessible via the MAPI address book. To open a MAPI object that points to a Mail-Gateway object in the directory, use HrCreateDirEntryId or HrCreateDirEntryIdEx.
See HrInstallGateway and related functions for more information about how to install a Mail-Gateway object.
For more information on accessing Mail-Gateway objects through MAPI and through directory access functions, see Using MAPI with Directory Objects.