On August 6, 2003 08:53 am, Whit Blauvelt wrote:
> You might find it much easier, although still a lot of work, to install a
> relaying mail server on the firewall that uses SpamAssassin and Razor
> called from the MIMEDefang milter in sendmail. I've also seen a Webpage
> somewhere on doing this using Qmail and SpamAssassin (you might google for
> it). This is all free software - the only investment is your time.
>
> Asking iptables to do it is putting the load in the wrong place, and
> failing to take advantage of the work already done in using mail daemons
> for this task.
>
> Whit
>
> On Wed, Aug 06, 2003 at 03:07:31PM +0530, Deshwal Chand wrote:
> > Hi,
> >
> > I am running IPTABLES on Redhat 7.2 box. We are running a mail server
> > behind this firewall. We receive lot of spam e-mails. Instead of
> > investing into the anti-spam s/w, I want to configure the IPTABLES to
> > read the contents on the packets and drop them based upon the filter
> > defined.
> >
> > Any help ......
> >
> >
> > Regards,
> >
> > Chand
Although it was a LOT of work and fair trial for me, (not being a sendmail or
QMail guru) I've got Qmail and spamassasin working using the spamassassin
filtering for spam and an antivirus scanner working as well... this requires
some serious CPU horsepower under load, but in many small business cases
can be done with your average desktop class power.
I haven't pushed the application yet, but I did grab about 350 mixed test
mails and throw them at it once to see how long it would take to process.
It loaded the box, and took about 8 minutes to process the works on an
AMD 1500 cpu, 756Mb ram, IDE disks and about 75% of that was the time for the
AV scanner to process several large zip files, which actually contained virus
triggers (not real viruses, but code that should trigger virus scanners)
The above has a $0 cost in terms of software code, but can be supported for a
nominal fee if required. (and b-t-w it beat the daylights outta the MS
implementation that work has.)
I REALLY don't recommend using IPTABLES with string matching to try and
replace spam filtering.
You MIGHT consider using IPTABLES, and RTBH to filter based on ip
addresses of known spammers, but I'm not sure that someone has come up with
an effective manner of combining these tools yet.
--
Alistair Tonner
nerdnet.ca
Senior Systems Analyst - RSS
Any sufficiently advanced technology will have the appearance of magic.
Lets get magical!
