Anti-Spam for Exchange Server 2007 with Hub Transport

Symptoms:
After Installing new Exchange 2007 server with Hub Transport, you realized it is not Anti-Spam Enabled. Many information and Best Practice only refer to Edge Transport. What if you don't have any budged to created Edge server or you only run small organization but must have Anti-Spam mechanism?

Solution:
Actually the Anti-Spam features can be installed directly into the Hub Transport module on the Exchange Server using Power Shell.
1. Run the Install-AntispamAgents.ps1 script. This script is located in the %system drive%/Program Files/Microsoft/Exchange Server/Scripts
2. Restart the Microsoft Exchange Transport service:
Restart-Service MSExchangeTransport
3. Specify the internal SMTP servers by using the InternalSMTPServers parameter on the Set-TransportConfig cmdlet
set-transportconfig –internalsmtpserver x.x.x.x
4. Check 'Server Configuration\Hub Transport', notice the 'Anti-spam Updates Enabled' set to 'True'. If it's not you need to run:
Enable-AntispamUpdates -SpamSignatureUpdatesEnabled $true -UpdateMode Automatic
5. Add quarantine mailbox for administrator to check, deleted, and send again (Approved) quarantined email
6. Do required configuration (SCL and custom configuration) for Anti-Spam features:
- Content Filtering
- IP Allow List
- IP Allow List Providers
- IP Block List
- IP Block List Providers
- Recipient Filtering
- Sender Filtering
- Sender ID
- Sender Reputation

More info: http://technet.microsoft.com/en-us/library/bb201691.aspx

Handling Exchange IMF & SCL

To enable IMF auto-updates:

1. In Registry Editor, navigate to the following registry key:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Exchange

2. Create the following value (DWORD):

ContentFilterState

and give it a value of 1.

To configure IMF to also add the SCL rating to the archived message:

1. In Registry Editor, navigate to the following registry key:

HKEY_LOCAL_MACHINE\Software\Microsoft\Exchange\ContentFilter

Note: You might not find this key in place. If that is the case, create a new key under the Exchange key and call it ContentFilter

2. Within the ContentFilter key, create the following value (REG_DWORD):

ArchiveSCL

and give it a value of 1.

restart the Simple Mail Transfer Protocol (SMTP) service

Custom Weighting Feature for Exchange IMF

IMF version 2 includes a completely new feature called the Custom Weighting Feature (CWF), which allows you to customize IMF even further. With CWF you can filter e-mail messages based on specific phrases within the body of the messages, the subject line or both.

Below is an example of specific phrases and values you can use in the MSExchange.UceContentFilter.xml file.

<?xml version="1.0" encoding="UTF-16"?>
<CustomWeightEntries xmlns="http://schemas.microsoft.com/2005/CustomWeight">
<CustomWeightEntry Type="BODY" Change="5" Text="abcde"/>
<CustomWeightEntry Type="BODY" Change="-5" Text="fghij"/>
<CustomWeightEntry Type="BODY" Change=”6" Text="klmno"/>
<CustomWeightEntry Type="SUBJECT" Change="MIN" Text="pqrst"/>
<CustomWeightEntry Type="BOTH" Change="MAX" Text="uvwxy"/>
</CustomWeightEntries>

Notes:
1. MSExchange.UceContentFilter.xml, should always be in the working path of IMF in latest update subfolder (be sure to check them regularly againts IMF Update)
2. You migh to restart SMTP services to make sure no problem while loading them
3. MSExchange.UceContentFilter.xml file should saved in Unicode format
4. SCL Result : a. determine by + and - change, b. if MAX match then reset to 9, c. if MIN macth then reset to 0.
5. CWLs will not match an entry to a substring of a word, but will match a shorter phrase to part of a longer phrase