Spam Assassin on Exchange 2003

February 20, 2008 by Kurt

At work we use Exchange 2003 as our email server, mostly because it was just so darn convenient to set up. Outlook and Exchange are pretty decent at filtering spam once you’ve installed the latest service packs. However, the amount of completely useless emails making it to my inbox recently spiked (Valentine’s Day may have had something to do with it). Time to bring out the big guns.

Spam Assassin is a groovy open source spam filter created by Justin Mason. So groovy, in fact, that it’s become the de facto standard in spam filtering. To solve my spam problem at work, I needed to get Spam Assassin working with Exchange. Or spend a lot of money on a commercial solution that would be just about as effective. Hmm…

Now, open source software like this is sometimes a pain to get working on a Windows box. Fortunately, setting up Spam Assassin on Exchange 2003 is pretty straightforward with help from some friends. Here is what you need to do:

Head on over to Christopher Lewis’ website* and download his ESA sink (i.e., plug-in) for Exchange.
Run the installer on your Exchange server. It will create the directory c:\ESA.
Rename c:\ESA\readme.txt to c:\ESA\readme (esa).txt
Download SpamAssassin for Win32 command-line tools, and sa-learn from the SaWin32 website. Unzip both into the same directory you installed ESA into above.
Create a new batch file, c:\ESA\spamc.bat with this in it:
@c:\esa\spamassassin.exe %*
Now you should be ready to rock. Check out the ESA readme file for usage information.

*Since I wrote this article, it looks like Chris’ website has gone down. You can still download the ESA Sink Installer (and source code) from the Nerd Fortress S3 bucket, or via The Wayback Machine.

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Posted in How To | Tagged email, exchange, spam, windows server | 17 Comments

17 Responses

on January 21, 2009 at 11:04 am | Reply Alwin

Eventually you changed the path to the spamassassin.bat file to the spamc.bat file within the esa configuration ini?

any other steps you followed to keep it running all of the time?
- on January 21, 2009 at 4:03 pm Random
  
  I don’t recall having to do anything else… Has anyone else had to take some extra steps not discussed in the post?
on March 19, 2009 at 12:44 pm | Reply Erik

Thank you for providing the steps. A great way to get spam filtering on our box. I just wish that the ESA Sink had a whitelist so it could ignore processing emails from a particular sender. We have a vendor we deal a lot with, and their emails come to us as Secure HTML emails. The warehouse gets them on PDA’s.

The problem is that the ESA sink converts these emails to text and then back to the original, but something happens in that process that now the HTML is posted as an attachment in Outlook and shows as garbage on all the PDA’s (they don’t even see the attachment).

We spend a couple days trying to narrow it down and now that we found it, it’s a bit of a bummer as we may have to abandon this solution altogether.
on January 23, 2010 at 4:19 pm | Reply Jesse

This howto seems so short compared to the others I’ve found with integrating in spamassasin with exchange 2003. The others go into details on perl installations, nmake setup, and installing modules within perl. Are you telling me that you have done these 6 steps and a little more esa configuration and you are on your way to a spamassasin filtering solution for your exchange server?

Here are the other links that go into depth on all you must do to get this working.

http://www.spamblogging.com/archives/000069.html

http://web.archive.org/web/20061230100228/http://www.openhandhome.com/howtosa300.html

thanks for the input.

jesse
- on April 5, 2011 at 8:54 pm Kurt
  
  Thanks for the extra links. Here’s another good resource:
  
  http://www.davidstephens.co.uk/2008/11/09/installing-spamassassin-on-windows-win32-for-microsoft-exchange/
on January 23, 2010 at 4:24 pm | Reply Jesse

I forgot to add e-mail notification when you respond so I placed this post up

jesse
- on March 30, 2010 at 9:16 pm Kurt
  
  That’s a good question. The SaWin32 project that is linked from the article is a native Win32 build that does not depend on perl from what I can recall.
  
  You will want to download the base Win32 command-line tools as well as sa-learn.
on June 15, 2010 at 2:20 am | Reply Nick

Fantastic stuff, thanks a lot for the instructions, works fine

Just to clear the confusion, this is what i had to do:
During installation of ESA, don’t run the batch file, install the rest of the stuff, configure the ini file and then run Install_ESA_Sink.bat

That should do the job
on June 16, 2010 at 8:01 pm | Reply Evan

Will this work with exchange 2010?
on October 15, 2010 at 12:00 pm | Reply Jess

THANK YOU, it’s working great within 10 minutes.

How do I help ESA learn to fix false-positives or false-negatives?
on April 5, 2011 at 12:12 pm | Reply Harry

hmmm… christophers site seems to be down. at least the link isn’t working anymore.
is there another way to get the esa sink?
- on April 5, 2011 at 8:56 pm Kurt
  
  You can download the ESA sink from my S3 bucket (hopefully Chris won’t mind).
  
  https://s3.amazonaws.com/nerdfortress/ESA-Setup.exe
  
  https://s3.amazonaws.com/nerdfortress/ESA-Source-2007-04-23.zip
  
  I haven’t tried it with recent versions of Exchange, but you can tweak the source code if need be to get things working.
- on April 7, 2011 at 6:15 am Harry
  
  thx a lot kurt, you made my day
on April 21, 2011 at 11:53 am | Reply Tom

You also need to update it with sa-update to fix the ” 3.4 FH_DATE_PAST_20XX The date is grossly in the future.” bug as it doesn’t recognise the year 2011..

See https://issues.apache.org/SpamAssassin/show_bug.cgi?id=6269
on May 14, 2011 at 5:43 am | Reply shamtest

I can’t seem to be able to reach this page from my droid!!!!
on October 7, 2011 at 2:36 pm | Reply Lukas

Hi guys.

I have only one problem with required_score. Even if I change required_score to in example 8, X-SPAM-SCORE show me that the required=6.3. I changed required_score in c:\ESA\etc\spamassassin\local.cf.

Any suggestions ?
on January 17, 2012 at 11:11 am | Reply Spamassassin in Exchange 2003 | Aloquevamos.com

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