XFOR: When You Select Remote Clients Support MAPI, BP9 is not Sent with Forwarded Messages

MORE INFORMATION

Even though the Microsoft Exchange MTA behaves as it has been configured, Microsoft recognizes the need to be able to send the X.400 protocol along with the message.

The need for the required behavior discussed in this article should become more distinct by looking at the scenario outlined below.

Microsoft Exchange Server acts as a common backbone for both Microsoft Exchange Server systems and non-Exchange X.400 systems. At Exchange systems off the backbone, administrative burden can be eased, by using a minimal configuration to connect to the Exchange X.400 backbone. This minimal configuration could for example include an address space of 'C=*' on the X.400 connector to the backbone. On the same connector, the 'Remote clients support MAPI' check box is activated, for maximal Exchange interoperability.

Without the hotfix discussed here, the X.400 protocol for forwarded messages would be dropped for messages sent over such an X.400 connector. On forwarding such a message from the Exchange backbone to a non-Exchange system, data loss will occur, because the message will not have a message body part.

The X.400 protocol for forwarded messages is sometimes referred to as BP9. Please note that the MS Exchange MTA behaves as described in this article, because it is configured that way. The fix discussed herein allows to configure the wanted behavior on a per connector basis. The default behavior for Exchange is to drop BP9 on X.400 links configured with the option 'Remote clients support MAPI'. Please do the following to allow BP9 being sent additionally, after applying the hotfix, for EACH X.400 connector you want Exchange's default setting to be changed:

1. Start the Exchange Admin module in raw mode using the following syntax:

   ADMIN -R

2. Change to the Connections container.
3. Highlight the X.400 connector that you want to change.
4. Click the Raw Properties entry on the File menu. This brings up the raw-property page of the selected connector.
5. In the "List attributes of type" box in the lower left corner of the property page, select "Non existing".
6. In the "Object attributes" list, select the Heuristics property by clicking it.
7. In the "Edit value" field enter 512 (0x200 hex) and click the Set button. It should become active when you type the value.
8. Click Apply and then click OK. This should close the raw-property page for this connector.
9. Check that your modifications have been applied properly by opening the raw-property page of the modified connector again. The "Heuristics" property with a value of 512 should show up, after "Existing" objects in the "List attributes of type" select box have been chosen.
10. Repeat steps 1 through 9 for each connector you want to modify.
11. If you want the modifications to take effect immediately, stop and restart the service Microsoft Exchange message transfer agent.

INSTALLATION

1. Run HOTFIX /I at a Windows NT command prompt.
2. Run HOTFIX /V at a Windows NT command prompt to verify that the fixed files have been installed properly.
3. Before proceeding to step 4, refer to the configuring instructions in the "More Information" section of this article.
4. For your changes to take effect, you must stop and restart all Microsoft Exchange Server services.