Last week I spent some time getting to grips with the Anti-Spam features of Microsoft Exchange Server 2007. I hadn’t previously seen or read much about them as we don’t have the Edge server installed – instead we are using an independent mail filtering package but I was keen to find if the built-in Anti-Spam features are comparable to the other mail filter in operation.

Without using an Edge Server, the Anti-Spam features can be installed directly into the Hub Transport module on the Exchange Server using Power Shell using the install-antispamagents.ps1 script which is located under Program Files\Microsoft \Exchange Server \Scripts. After installation, the Exchange Transport service will need to be restarted to kick things into touch.

I had to register our external SMTP mail filter using the command Set-Transport Config:

set-transportconfig –internalsmtpserver x.x.x.x

Then I needed to check that the Anti-Spam updates were working automatically using the cmdlet:

get-antispamupdates

The Anti-Spam updates were set to manual, the command to enable them was:

Enable-AntispamUpdates -SpamSignatureUpdatesEnabled $true -UpdateMode Automatic

A further check showed that the updates were now being collected automatically and that UpdateMode is set to Automatic.

Now we have a new Anti-Spam tab under our Microsoft Exchange Server Hub Transport module with various Anti-Spam facilities available.

The first thing to do is ensure Content Filtering is configured by setting up a new Mailbox for quarantined mail then double-clicking the Content Filtering tab under the Anti-Spam tab in the Hub Transport in the menu where you fill four tabs: General, Custom Words, Exceptions and Action.

The General tab is purely informational, the Custom Words tab is where you put your own words and phrases to specifically block (override the SCL to 9) or not block (override the SCL to 0); SCL is the Sender Confidence Level. Particular recipients can be excepted in the Exceptions tab (in our case some system log files that are sent to and stored in the email system). The final tab Action tells the Content Filter what to do based on SCL thresholds – Delete, Reject or Quarantine (to Mailbox). Quarantine to a Mailbox requires an administrator to check the email – open it and either Delete it or click Send Again to approve it.

Further Reading

• Microsoft: How to Enable Anti-Spam Functionality on a Hub Transport Server
• Microsoft: Configuring Anti-Spam Features to Reduce the Volume of Spam
• Microsoft: Managing Anti-Spam and Antivirus Features

Related

• Configuring incoming mail on MOSS 2007 and Exchange 2007
• Neigbourly tensions: Exchange Server 2007 and Exchange 2000
• Exchange Server 2007 Curiosities
• Exchange Server 2007 SP1 … the wait is over
• GFI Mail Archiver now supports Exchange Server 2007