Site-wide server-side rules in Exchange 2003

Question

I have a mail server that scans inbound email messages with SpamAssassin before passing messages to Exchange 2003. When a message is considered spam, it is marked with a certain header. Is there a way to have Exchange 2003 automatically put these messages in each user's junk mail folder based on the existence of this header?

I realize I could add an Outlook rule for every user. I also realize that this rule would actually be implemented server-side. Adding a rule for every user seems hard to implement/maintain. Is there a way to add a global rule that works on all mailboxes?

From this question, it looks like Exchange 2007 has something called transport rules. Is there a way to get similar behavior in Exchange 2003?

Answer 1

There are people who claim to have gotten what you're describing to work by installing the Intelligent Message Filter and modifying the "MSExchange.UceContentFilter.xml" configuration file. You can create "CustomWeightEntry" records in that file that match text that SpamAssassin puts into the subject like and use that to assign a custom SCL.

Have a look here:

• http://technet.microsoft.com/en-us/library/aa996624(EXCHG.65).aspx
• http://technet.microsoft.com/en-us/magazine/2006.10.weightlists.aspx?pr=blog

Personally I've never tried it. It looks pretty straightforward, though.

Answer 2

Unfortuantely the capabilites of Exchange 2003 do not allow filtering based on any type of header information, like you can in Exchange 2007. If you are able to specify what your anti spam software puts in your header, you can put a specific X-SCL header that will be recognised by the IMF filter in Exchange. Information on the different kinds of stamps recognised by Exchange can be found here.

If you cannot modify the header information, then there are some third party tools however that can help you do this. IMFTune for example will allow you to adapt the IMF filter built into Exchange 2003 SP2, to filter spam based on header information.