Postfix Integration - Run another filter first

Joseph Jamieson jjamieson at
Thu Aug 7 21:43:49 IST 2008

That's a good possibility - I will read more on how messages are
inspected and handled by postfix.

I could probably have a different process inspect the hold queue,
process it first, then drop it into another folder which MailScanner
monitors.    Ahh, this all reminds me too much of CC:Mail and MSMail!
Q and MBG ftw.

I mean, I guess I could set up two separate postfix daemons - one to run
the first set of filters, and then pass the off to postfix #2 which
would run MailScanner, but I'd really like to avoid this scenario.

-----Original Message-----
From: mailscanner-bounces at
[mailto:mailscanner-bounces at] On Behalf Of Leland
J. Steinke
Sent: Thursday, August 07, 2008 4:22 PM
To: MailScanner discussion
Subject: Re: Postfix Integration - Run another filter first

My recollection is that the cleanup(8) daemon is what places messages in

the hold queue.  MailScanner picks them up there and drops them into 
incoming when it's done. indicates

optional "light-weight content inspection" in the BUILTIN_FILTER_README.

If all else failed, maybe you could set up header_checks to use the 
FILTER action on Received: headers to a daemon that inserts some other 
header which you could then use as a trigger for the HOLD action after 
the message is re-injected.  I make no promises that this would work at 
all, but it would be cool if it did.  ;-)

Joseph Jamieson wrote:
> Greetings,
> I'm pretty new to MailScanner, but I do have a working system and it
> 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
> 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
> 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
> filter set up in the (for instance, dspam) MailScanner
> 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
> 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?
> Thanks in advance.

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