Preserving Foreign System Message Information

In some cases the information provided by the foreign system must be preserved in a MAPI message when messages are transferred through a gateway. Examples of information that may need to be preserved are trace information, message headers, and correlation identifiers.

The MAPI PR_TRANSPORT_MESSAGE_HEADERS property holds the message headers of the foreign message. If the foreign message is in the process of being automatically forwarded and is sent back to the gateway, these headers need to be added back into the message. Dropping the header information can result in a message loop.