Microsoft KB Archive/268887

= XADM: Delivery Receipts Contain &quot;Unknown&quot; for Original Message Detail =

Article ID: 268887

Article Last Modified on 10/26/2006

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APPLIES TO


 * Microsoft Exchange Server 4.0 Standard Edition
 * Microsoft Exchange Server 5.0 Standard Edition
 * Microsoft Exchange Server 5.5 Standard Edition

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This article was previously published under Q268887



SYMPTOMS
An Exchange Server computer may return a delivery receipt to the message sender that contains the string &quot;Unknown&quot; in the To, Subject, and Sent lines.



CAUSE
This problem can occur because of a limitation in X.400 delivery receipt functionality. A feature to improve X.400 delivery receipt is included in Exchange Server, but if a message path follows certain architectures, this limitation is unavoidable. Exchange Server also attempts to resolve the delivery receipt message fields from information in the message ID. The message transfer agent (MTA) attempts to match the message ID to a message in the local Exchange Server store. If the message is not available in the local Exchange Server store, the message generates the &quot;Unknown&quot; string.



WORKAROUND
To work around this problem, use only X.400 site connectors and Exchange Server computers in an organization, or use only Internet Mail Service or remote procedure call (RPC) site connectors to reduce or eliminate the architectures that lead to this problem. If you create a replication connector, you can also alleviate the problem in some configurations.



MORE INFORMATION
The X.400 specification generates reports based on the information in the message envelope. The envelope may not contain the To, Subject, or Sent information in the delivery report, and in the case of a delivery receipt, Exchange Server does not use the envelope to fill the fields. Therefore, this information is not returned by the X.400 system that receives the message.

To overcome this limitation of the X.400 specification, Exchange Server uses the Content Correlator attribute. This attribute is returned in the envelope to the originating system, which then attempts to map this by using the MTS-ID to the original message, which allows the receiving system to extract the To, Subject, and Sent information from the original message.

This does not work if the original message no longer exists on the originating system.

Certain architectures also prohibit this system from working. The Exchange Server Internet Mail Service does not preserve this attribute, and so any architecture that crosses both an X.400 connector and an Internet Mail Service connector does not provide fully populated delivery receipt fields.

Even if this attribute is preserved, the attribute relies on a mechanism at the receiving end to match the Content Correlator attribute and MTS-ID that is similar to the current Exchange Server X.400 mechanism, and as such is Exchange Server-specific and does not work on any non-Exchange Server mail system.

Ideally, any Internet Mail Service in the message path would be able to retrieve and translate the original message information when the Internet Mail Service receives mail from an X.400 system. However, this is not feasible when using any variation on this mechanism because the relay server almost certainly does not contain a copy of the original message.

For additional information about this feature implementation, click the article number below to view the article in the Microsoft Knowledge Base:

147545 XADM: Delivery Receipt Has Unknown for To, Subject, and Sent

Additional query words: DR Delivery Receipt Unknown IMS foreign cc

Keywords: kbnofix kbprb KB268887

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