Option to strip attachments for messages that generate an NDR

This article describes an option that you can enable on a computer that is running Exchange 2000 Service Pack 2 (SP2) or later to remove attachments if a message cannot be delivered. For more information about the latest service pack for Microsoft Exchange 2000 Server, click the following article number to view the article in the Microsoft Knowledge Base: Note Starting with Microsoft Exchange Server 2003 Service Pack 1 (SP1), Exchange Server will automatically remove an attachment that is 10 megabytes (MB) from DSN messages that are generated by the SMTP engine. The registry key that is specified in the "More Information" section can be used to modify the default behavior.

If you enable this option, you can save server and network resources. However, there are drawbacks to this implementation of Simple Mail Transfer Protocol (SMTP) attachment stripping. If you enable this option to strip the attachments from the non-delivery report (NDR), the details that are necessary to display the notification in the preview pane are also stripped, and the originator of the message cannot use the Send Again option. If the originator of the message tries to use the Send Again option from the NDR, the originator of the message receives the following error message: However, the originator of the message cannot resend the message, even by using the method in the error message.

To enable this option, you need to edit the registry.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.
To enable this option:

1. Start Registry Editor (Regedt32.exe).
2. Locate and click the following key in the registry:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\SMTPSVC
3. On the Edit menu, click Add Key, add the following registry key, and then click OK:
   Key name: Queuing
   Class: Leave the class blank
4. Click the Queuing registry key that you just added. On the Edit menu, click Add Value, and then add the following registry value:
   Value name: MaxDSNSize
   Data type: REG_DWORD
   Radix: Decimal
   Value data: This value is the size limit in bytes; messages that are larger than this value that generate an NDR do not return attachments or full message properties.
5. Close Registry Editor.

You must restart the SMTP service for this registry change to take effect.