The following topics discuss message identifier tracking when a message is transferred from Microsoft Exchange Server to a foreign system and when a delivery or nondelivery report is returned from the foreign system to Microsoft Exchange Server. It is important to track message identifiers so that useful debugging information ends up in the Microsoft Exchange Server Administrator error logs, so message loops can be avoided, and so users can receive proper reports about a message.
There are several steps in this process:
The client application creates a new message and submits it to the server.
The server transfers the message to a gateway.
The gateway translates the message to the foreign system’s message format and submits it to the foreign system.
The foreign system sends a report back to the gateway. Note that this may happen a long time after the gateway sends the message which triggered the report.
The gateway translates the report into a MAPI message and submits it to the server.
The server delivers the report to the user who sent the original message.