Backscatter & challenge response {Scanned by Allteks Mailsafe}

Edward Prendergast edward.prendergast at
Fri Apr 11 11:50:38 IST 2008

You could take a look at SpamAssassin's VBounce - this identifies different
kinds of bounce messages and it may specifically look out for
challenge/response. If it does you could try hiking the score up but there
is a high risk of losing legitimate challenge/response messages with this

-----Original Message-----
From: mailscanner-bounces at
[mailto:mailscanner-bounces at] On Behalf Of Paul
Houselander (SME)
Sent: 11 April 2008 11:08
To: 'MailScanner discussion'
Subject: RE: Backscatter & challenge response {Scanned by Allteks Mailsafe}

If your domains outbound e-mail goes via servers you control/have ms running
on them take a look in MailScanner.conf at the Watermarking section.

I run ms for many domains not all send their outbound via me so I use
rulesets to only add a watermark for certain domains and only check them for
certain domains, has worked a treat, only problem is that some read receipts
and out of office replies get incorrectly flagged, small price to pay to
block all the rubbish I think!

> Hi there,
> Sorry for jumping in on this - but wondered how you went about
> watermarking? I use Sendmail / MS
> Regards
> > Hi
> >
> > In common with lots of people I've seen a massive increase in the
> amount
> > of
> > backscatter my domains are getting. I implemented watermarking which
> has
> > helped a great deal.
> >
> > What I'm getting complaints about now are the mails coming in from
> > annoying
> > challenge response systems, the mails don't come from postmaster, <>
> > etc...
> > so the watermark does not get looked at.
> >
> > Just wondered if anyone had any bright ideals as to how to combat it?
> >
> > I've been looking at a selection I've been sent through this morning
> and
> > there doesn't seem to be anything consistent about them and there not
> > hitting many spamassasin rules.
> >
> > Cheers
> >
> > Paul

MailScanner mailing list
mailscanner at

Before posting, read

Support MailScanner development - buy the book off the website! 

The information in this email is confidential and may be legally privileged.
It is intended solely for the addressee. Access to this email by anyone else
is unauthorised. If you are not the intended recipient, any action taken or
omitted to be taken in reliance on it, any form of reproduction,
dissemination, copying, disclosure, modification, distribution and/or
publication of this E-mail message is strictly prohibited and may be
unlawful. If you have received this E-mail message in error, please notify
us immediately. Please also destroy and delete the message from your

More information about the MailScanner mailing list