Max SpamAssassin Size problems

Ken A ka at
Mon Aug 28 17:15:20 IST 2006

Kash, Howard (Civ, ARL/CISD) wrote:
>> Why not just set the Max SpamAssassin Size to 50k
> You'll still truncate images.  I currently have it at 150k and it
> still truncates images (either large ones or messages with lots of
> attached images).
>> or the partial-image-detection rules to 0?
> This is an option, but you give up some SPAM detection capability.
> The plugin doesn't specifically test for partial images, but corrupt
> images in general, which truncated images are a subset of.  Some
> image spammers have intentionally corrupted the image in such a way
> that many email clients will still render them readable, but image
> analysis utilities balk on them.  So messages with corrupt images are
> given a higher score.
> And this isn't just about images, supposedly someone is working on a
> plugin to analyze Word documents for spam content.   It may have the
> same problem with truncated Word attachments.

Exactly. So where's the best place to fix this? The most important 
argument in the "Don't change MailScanner" camp is that you'd be opening 
a door to DoSing a system, and defeating the purpose of "Max 
SpamAssassin Size" if you try to pass only complete messages, images or 
word docs to SA. This is absolutely correct, and must be avoided.

I agree, but I think this is an issue that needs to be wrestled with 
more so that SA plugins developers are aware of how MailScanner works 
and things get worked out the best way possible. We aren't there yet.

What if you could also pass a flag to SA that said, 'hey, SA, this might 
be a partial image!'. Then SA could pass that to the plugins that might 
FP on partial images? Parts of a system need to be aware of how other 
parts work. ..resisting the urge to quote rodney king. ;-P

Ken A.

> Howard

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