

Text taken from MS Article located (at time of writing) at:
http://support.microsoft.com/default.aspx?scid=kb;en-us;837794


Update available in Exchange Server 5.5 to control whether the Internet Mail Service
suppresses or delivers NDRs

Article ID : 837794 
Last Review : November 10, 2005 
Revision : 6.0 

Important This article contains information about how to modify the registry.
Make sure to back up the registry before you modify it.
Make sure that you know how to restore the registry if a problem occurs.

On This Page
 SUMMARY 
 RESOLUTION 
   Hotfix information 
     Prerequisites 
     Restart requirement 
     Hotfix replacement information 
     File information 
 MORE INFORMATION 
 APPLIES TO 

SUMMARY
An update to Microsoft Exchange Server 5.5 is available
that introduces a new feature that you can use to control
how non-delivery reports (NDR) are processed by the Internet Mail Service.
After you apply the hotfix that is described in this article,
add the SuppressNDROptions registry entry to the following registry subkey.
Then, set the SuppressNDROptions registry entry to the appropriate value,
depending on whether you want the Internet Mail Service to suppress or deliver NDRs:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIMC\Parameters 

RESOLUTION
Hotfix information

A supported feature that modifies the default behavior of the product
is now available from Microsoft,
but it is only intended to modify the behavior that this article describes.
Apply it only to systems that specifically need it.
This feature may receive additional testing.
Therefore, if you are not severely affected by the lack of this feature,
we recommend that you wait for the next update that contains this feature.

Prerequisites
This hotfix requires Microsoft Exchange Server 5.5 Service Pack 4 (SP4).

Restart requirement
You do not have to restart your computer after you apply this hotfix.

Hotfix replacement information
This hotfix does not replace any other hotfixes.

File information
The English version of this hotfix has the file attributes (or later file attributes)
that are listed in the following table.

Date         Time (UTC)   Version     Size     File name
-------------------------------------------------------
01-Apr-2004  22:33                    319,488  Uninst.exe
30-Mar-2004  19:55        5.5.2658.3  209,680  Imcmsg.dll
30-Mar-2004  19:57        5.5.2658.3  505,104  Msexcimc.exe

MORE INFORMATION
After you apply the hotfix that is described in this article,
add the SuppressNDROptions registry entry to the following registry subkey
and then set the registry entry to the appropriate value:

HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIMC\Parameters

To configure the way that the Internet Mail Service processes NDRs: 

Warning Serious problems might occur if you modify the registry incorrectly
by using Registry Editor or by using another method.
hese 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.

1. Click Start, and then click Run. 
2. In the Open box, type regedit, and then click OK. 
3. Locate and then click the following registry subkey: 
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIMC\Parameters  
4. On the Edit menu, point to New, and then click DWORD Value. 
5. Type SuppressNDROptions, and then press ENTER. 
6. On the Edit menu, click Modify, and then follow these steps:
 Set the Base type to hexadecimal. 
  To enable this feature so that the Internet Mail Service does not deliver NDRs,
    type 1 in the Value data box. 
   To enable this feature so that the Internet Mail Service does not generate NDRs,
    type 10 in the Value data box. 
   To enable this feature so that the Internet Mail Service does not deliver any NDRs
    if an SMTP address is missing in the return address field,
    type 100 in the Value data box.

    Note If the SuppressNDROptions registry entry is either not present or
    if the registry entry is set to 0 (zero), the feature is not used.
 
7. Quit Registry Editor.
8. Restart the Internet Mail Service.

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APPLIES TO
 Microsoft Exchange Server 5.5 Standard Edition 
