Intelligent Message Filter updates are supported in the following configurations:

• On a server that is running Exchange Server 2003 SP2 or a later version of Exchange Server 2003, with Intelligent Message Filter enabled
  
• On a server that is running both Microsoft Small Business Server and Exchange Server 2003 SP2 or a later version of Exchange Server 2003, with Intelligent Message Filter enabled
  

Intelligent Message Filter updates are available every first and third Wednesday through Microsoft Update and Automatic Updates technologies. Organizations can also use Windows Server Update Services (WSUS) and System Management Services to deliver the updates in a corporate environment.

When the Exchange Server team cannot release the update on a Wednesday, they will release the update on the following day. If the update is unavailable on a Thursday, the update for that week will be skipped. Then, the update will be released on the next scheduled Wednesday.

The Intelligent Message Filter is language-independent. Intelligent Message Filter updates are offered for all language versions of Exchange Server 2003.

After you enable the Intelligent Message Filter in Exchange System Manager, to enable Intelligent Message Filter updates, you must create the ContentFilterState registry entry. To do this, follow these steps.

Caution:
Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data.

1. Click Start, click Run, type regedit, and then click OK.

2. Expand the following registry sub key: HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange

3. In the left pane, click Exchange. Then, right-click in the right pane, point to New, and then click DWORD Value.

4. Type ContentFilterState, and then press Enter to name the new registry entry.

5. Right-click ContentFilterState, and then click Modify.

6. In the Data value box, type 1, and then click OK.

7. Quit Registry Editor.

8. In the Services snap-in, restart the Simple Mail Transfer Protocol (SMTP) service.

An Intelligent Message Filter update package includes both a .dll file and a .dat file for the filter. The version information for the Intelligent Message Filter update files MSExchange.UceContentFilter.dll and MSExchange.UceContentFilter.dat reflects the Exchange Server build versioning in the following format:

MajorProductVersion.MinorProductVersion.MajorNumber.MinorNumber.

The version numbers are consistent with the Exchange Server build number, such as 6.5.XXXX.X. This makes it easier to identify the version number of the Intelligent Message Filter update that you have installed on the computer.

The update package version of an Intelligent Message Filter update is based on the date of the package build. Additionally, the update package version of an Intelligent Message Filter update is identified in the package name. For example, an update package that is dated December 14, 2005 has the following title:

Update for Intelligent Message Filter on Exchange Server 2003: 2005.12.14 (KB907747)

The executable package for this update has the following file name:

IMF-KB907747-2005.12.14-x86.exe

By default, when the Intelligent Message Filter is installed together with Exchange Server 2003 SP2, a new folder that is named MSCFV2 is created. The Intelligent Message Filter engine and the .dat file are stored in the following location:

Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2

Subsequent updates are stored in subfolders under the MSCFV2 folder. The subfolders are named according to the version number of the updates. For example, after you install several updates, the folder structure may appear as follows:

Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2

Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2\6.5.7612.0

Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2\6.5.7615.0

Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2\6.5.7620.0

The registry entry that is described in the "How to Enable Updates" section reflects the state of the Intelligent Message Filter. This registry entry also serves as a reference point for the Intelligent Message Filter update package installer and for the Microsoft Update detection logic. This registry entry enables the update package installer to know whether the Intelligent Message Filter update functionality has been enabled on the server. If the registry entry does not exist, Intelligent Message Filter update packages are not offered. If the registry entry exists, Intelligent Message Filter update packages are offered.

The existing active version of the .dat file that is currently installed on the computer is recorded under the following registry sub key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Exchange Server 2003\SP3

For example, after you install the IMF-KB907747-2005.12.14-x86.exe update, the registry entry is similar to the following:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Exchange Server 2003\SP3\KB907747

This registry entry is verified every time that an update is offered for installation. If an update is successfully installed, the registry entry is updated. The update package installer knows which update is currently being installed. The update package installer compares that value to the current registry entry value. If the value is earlier than the update that is currently being offered, the update package installer performs the following actions, in this order:

1. Verifies that Exchange Server 2003 SP2 or a later version is installed on the server.
   
2. Records the existing active version number from the following registry entry: HKEY_LOCAL_MACHINE\Software\Microsoft\Updates\Exchange Server 2003\SP3.
   
3. Creates a subfolder that is named the same as the build number. This subfolder is created in the MSCFV2 folder. The path of the folder is similar to the following: Drive_Letter:\Program Files\ExchSrvr\Bin\ MSCFV2\BuildNumber.
   
4. Copies the Intelligent Message Filter .dll file and the Intelligent Message Filter .dat file to the newly created subfolder.
   
5. Registers the Intelligent Message Filter .dll file.
   
6. Updates the registry key based on the update version number.
   
7. Deletes all updates that exist on the system except for the current update that has been installed by the update package installer and the last two updates. Therefore, after the first three updates, the next update removes the oldest update. This always leaves the latest three updates on the computer. Updates are installed in a sequential order. For example, if updates U1, U2, U4 are installed, the next update that can be installed is U5 or a later update. When U5 is installed, U1 is removed.
   
8. During the update process, the update package installer restarts the IIS Admin Service for the package to take effect.
   

The latest Intelligent Message Filter updates can be uninstalled by using Add or Remove Programs in Control Panel. If you uninstall the latest Intelligent Message Filter update, the files from the corresponding subfolder in the MSCFV2 folder are removed. Additionally, the registry entry under the following sub key is removed:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Updates\Exchange Server 2003\SP3\KB907747

If the Intelligent Message Filter update packages have been uninstalled by using Add or Remove Programs, the base version is re-registered. Therefore, the Intelligent Message Filter is functional based on the original .dat file that was shipped in Exchange Server 2003 SP2.

How to Manually Install an Update or Roll Back to an Earlier Version

You can also manually install the Intelligent Message Filter update by browsing the Microsoft Update site, scanning for updates, and then selecting the Intelligent Message Filter update.

When it is required, you can quickly roll back the Intelligent Message Filter version by re-registering the .dll file from any one of the three folders that contain the last three updates. To do this, follow these steps.

Note:
For this example, assume that the following conditions are true. The three folders are as follows and you want to register Intelligent Message Filter version 6.5.7615.0. Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2\6.5.7612.0 Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2\6.5.7615.0 Drive_Letter:\Program Files\Exchsvr\Bin\MSCFV2\6.5.7620.0

To manually install an update or roll back to an earlier version

1. Click Start, click Run, type the following command, and then click OK: regsvr32 "Drive_Letter:\\Program Files\Exchsvr\Bin\MSCFV2\6.5.7615.0\MSExchange.UceContentFilter.dll"

2. Click OK to accept the registration confirmation message.

3. Click Start, click Run, type iisreset, and then click OK.

• When new service packs for Exchange Server 2003 are released, you might not be able to immediately upgrade to the new service pack. For example, suppose that Exchange Server 2003 Service Pack (SP3) is released. You continue to install the Intelligent Message Filter updates on schedule. Later, if you install the new service pack (Exchange Server 2003 SP3), the Intelligent Message Filter update is replaced by the version of the Intelligent Message Filter that is available in Exchange Server 2003 SP3. In this scenario, you must manually install the latest Intelligent Message Filter update.
  
• When you regularly update the Intelligent Message Filter, at some point in time, you may reinstall a service pack. In this scenario, the Intelligent Message Filter update is replaced by an earlier version of the Intelligent Message Filter update that was available with the service pack. You must manually install the latest Intelligent Message Filter update.
  

If you enable the Custom Weight List functionality on the server that is running Exchange Server 2003 SP2, you must manually copy the Custom Weight List file MSExchange.UceContentFilter.xml to the newly created MSCFV2 folder.

After the Intelligent Message Filter updates, you have to manually copy the following Custom Weight List file to the subfolder of the MSCFV2 folder that was created during the update: MSExchange.UceContentFilter.xml.

The subfolder of the MSCFV2 folder contains the updated filter.

For more information about the Custom Weight List, including a sample XML file, see the Microsoft Exchange Server 2003 Service Pack 2 Release Notes at http://go.microsoft.com/fwlink/?linkid=52072.

The Intelligent Message Filter is not supported in a clustered environment. Therefore, Intelligent Message Filter updates are not offered to Exchange Server 2003 servers in a clustered environment.

Note:
Intelligent Message Filter updates are supported in Network Load Balancing clusters.

When you select the Automatic option in Automatic Updates, Intelligent Message Filter updates, together with other updates, are downloaded and installed on the computer without user intervention. However, you should not enable Automatic Updates to automate installation of Intelligent Message Filter updates. When you use Automatic Updates, the following options are available:

1. Automatic download and installation of an update
   
2. Automatic download of an update
   
3. Notification of an update
   

These options are per computer and cannot be applied to an individual update. Because an automatic download and installation of the Intelligent Message Filter update will cause a restart of the IIS Admin Service, make sure that this setting is set for option 2 on servers that are running the Intelligent Message Filter. This will prevent any unplanned downtime. Also, it is recommended that you apply Intelligent Message Filter updates when there is a reduced load on the server to minimize disruption of services.