DSPAM and Sendmail

User Ernie ernie at puremail.eis.net.au
Wed Oct 26 17:15:02 PDT 2005


DSPAM is not a milter, it's a stand alone application that can run as a
daemon or be piped to directly. It's basically an advanced adaptive spam
filter written in C. I am currently running MailScanner -> SpamAssassin as a
gateway feeding a bunch of hosting servers and client mailservers, it's been
working for a year but a few problems have cropped up that make me want to cut
to DSPAM. Firstly the Perl nature of the current setup uses stacks of RAM as
I add more MailScanner processess to handle the load.  Secondly a lot of SPAM
is creeping through as the spammers get smarter, and I am always having to
tweak rulesets.  Lastly the whole set up is slooowww, especially if you
use a lot of DCC/Pyzor, and other offsite checks, the average mail delay as
reported by the vspan GUI, is about 25sec, and can be minutes in busy
periods, hence the need to seek change. DSPAM is a C program, small footprint
very fast especially if you use MySQL for the backend database. It has
fantastic SPAM capture rate, and a GUI for clients to edit quarantined SPAM.

I have DSPAM 3.6.0 from the ports collection running on 2 FreeBSD boxen, 
a 5.4-STABLE and a 6.0-RC1 machine, just as the Mlocal delevery agent 
which then passes to procmail on one machine and just to mail.local on the other machine, 
both configs work fine. I thought I would be smart and set the delivery agent 
in the dspam.conf file to /usr/sbin/sendmail and see what happened, got a mail loop and the
queue filled up and I had to kill the process. So my problem is how to get
DSPAM, remembering that it is set as the Mlocal program on the recieving
sendmail process, to pass the mail after it has finished with it to the
sendmail process that can do both external delivery to another email server
or to a local delivery program like procmail? 


{Internet} --> [Inbound Sendmail] -->[DSPAM] --> [Outbound Sendmail] --> [Other Mail Servers] 
                                                       \
                                                     [procmail]-->[local users]



I sort of thought it might be the sendmail process that uses the submit.cf file, however it does not seem
to have a Mlocal entry that makes sense to me.

- Ernie.





> Hi Ernie,
>   I don't know DSPAM, is it a "milter"  like mimedefang and 
> spamassassin?  I use mimedefang and spamassassin (mimedefang calls 
> spamassassin) in a gateway spam filter/virus scanner etc config.  In 
> my /etc/mail/hostname.mc file I put in
> dnl # icarz customizations here
> INPUT_MAIL_FILTER(`mimedefang', 
> `S=local:/var/spool/MIMEDefang/mimedefang.sock, 
> F=T,T=C:15m;S:4m;R:4m;E:10m')dnl
> define(`confINPUT_MAIL_FILTERS', `mimedefang')dnl
> dnl Custom rate limits should be OK with 1 gig
> 
> define(`confCONNECTION_RATE_THROTTLE',`10')
> define(`confMAX_DAEMON_CHILDREN', `40' )
> 
> define(`SMART_HOST', `mailhost.icarz.com')
> 
> 
> You can change the mail filter to be any mail filter.  The SMART_HOST 
> sends everything to my real mail server.  My mx records point to this 
> host.  I am sure there are better configurations,  but this was easy.
> 
> I hope this helps you with you question,
> Ken
> ----- Original Message ----- 
> From: "User Ernie" <ernie at puremail.eis.net.au>
> To: <freebsd-isp at freebsd.org>
> Sent: Tuesday, October 25, 2005 5:32 AM
> Subject: DSPAM and Sendmail
> 
> 
> >I am trying to get the DSPAM 3.6.0 port running as an SMTP relay 
> >gateway
> > receiving/filtering mail for several hosting servers. I am using
> > FreeBSD 5.4-STABLE and sendmail. On the DSPAM website it only gives
> > examples for either DSPAM as Mlocal delivery, or using Postfix as a 
> > relay.
> > I am not familiar with the FreeBSD dual sendmail instance setup, so 
> > I can't
> > get my head around how to configure Sendmail to listen to port 25 
> > and do it's
> > usual RBL checks I have set up, then pass mail to DSPAM, then finaly 
> > have DSPAM
> > pass it back to sendmail to forward it to the correct mail hosting 
> > server.
> >
> > Has anyone done this, or can anyone suggest what to try? I had a 
> > look at the
> > perl dspampd script but with no instructions I was stuck there as 
> > well.
> >
> > I also posted the question to the DSPAM mail list last week and got 
> > no
> > replies.
> >
> > - Ernie.
> 
> !DSPAM:435f7f7149181828790097!
> 
> 
> 
> 


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