Postfix Integration - Run another filter first

Julian Field MailScanner at
Thu Aug 7 21:14:24 IST 2008

Joseph Jamieson wrote:
> Greetings,
> I’m pretty new to MailScanner, but I do have a working system and it 
> works.
> I am having trouble tracking down a few bits of information, though – 
> and this is mostly a Postfix question but I figured someone here might 
> know.
> MailScanner uses the Postfix header-checks “HOLD” feature to scan the 
> messages. Postfix drops the message into the hold folder, and every 
> few moments MailScanner will check the folder, scan all the messages, 
> and then drop it into a folder for postfix to grab and continue 
> sending the message on its way.
> At what time in the process does Postfix do this? It appears that 
> postfix will do this before pretty much anything else. So, if I have a 
> filter set up in the (for instance, dspam) MailScanner 
> always gets a hold of the message first. What if I wanted to use dspam 
> to tag a message probability, and add some scores to SpamAssassin 
> (which is run by MailScanner?) That way, MailScanner remains the only 
> system that’s doing any tagging, quarantining, etc.
> DSPAM is just an example. I can think of several other nice little 
> things I’d like to be able to do, too.
> So, I guess the question is: Is there any way to run a filter via 
> Postfix **before** MailScanner gets its turn? Or do I have it all 
> wrong here?
You could implement DSPAM (or others) as a generic virus scanner or a 
custom spam scanner within MailScanner. How about that approach instead? 
It will take you a bit of digging in the MailScanner code to implement, 
but the hooks are there, and I probably even wrote you some sample code 
in or /usr/lib/MailScanner/MailScanner/CustomFunctions/*.pm.


Julian Field MEng CITP CEng
Buy the MailScanner book at

MailScanner customisation, or any advanced system administration help?
Contact me at Jules at Jules.FM

PGP footprint: EE81 D763 3DB0 0BFD E1DC 7222 11F6 5947 1415 B654
PGP public key:

This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

More information about the MailScanner mailing list