Re: [exim] 2nd Stage DNS blocking

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Author: Always Learning
Date:  
To: Exim
Subject: Re: [exim] 2nd Stage DNS blocking

On Sat, 2016-10-08 at 14:06 +0300, Lena@??? wrote:

> Honest users send non-spam messages from dynamic IP-addresses.


But do those "honest" (better: "genuine") users have:-

(1) rDNS ? Probably not because it is a dynamic IP address with a host
name, if a host name actually exists, like
123-123-123-66.dymanic.example.net


(2) A HELO/EHLO name which resolves to the IP address being used ?
Probably not.


How can the "honest" receivers of emails (MTA sites) distinguish (or
separate) the "honest" incoming traffic from the usual flood of
"dis-honest" traffic sent from the same range of IP address ?

Why are "honest" users with dynamic IP addresses, unable to route their
outgoing email traffic via a smarthost or via a very cheap VPS running
MTA software like Exim ? VPS's usually have between 1 and 8 fixed, or
static, IPv4 addresses plus the ability to create DNS records such as A
and MX.

> Those dynamic IP-addresses often are in blacklists.


Because mail admins, like me for example, are unhappy at the vast amount
of spam originating from ranges of dynamic IP addresses. After a while,
we block hosts like

*airtelbroadband.in
*adsl.alicedsl.de
*dynamic.se.alltele.net
*alshamil.net.ae
*adsl.anteldata.net.uy
*aphie.info
*pools.arcor-ip.net
*static.arcor-ip.net
*as9105.com
*as13285.net
*as43234.net

et cetera, et cetera.

    *host..
    *dyn.....

    
etc.

plus the commercial spammers. For example

*descene.org                 # 29 Dec 2014 : Ebay junk mail
*dmdelivery.com              # Chinese junk mail
*dnsinspect.com
*edmspread.com               # Chinese junk mail : 17 Sept 2015
*emsmtp.com                  # Chinese junk mail
*emsmtp.us                   # Ebay spam 12 April 2016
*everydayedeals.com          # 21 May 2015


*glassdoor.com               # 20 Sept 2015
mout-xforward.gmx.net
*imtreview.com               # 02 March 2016



*mailgun.net                 # 15 April 2015, Rackspace service
*mailgun.us                  #  ditto
*mailminion.net              # 17 May 2016
*mandrillapp.com             # MailChimp
*mcsv.net
*mkt7162.com                 # IBM spam
*mmsvr.net                   # 17 May 2016
*msgfocus.com                # = Adestra Ltd, email newsletter and
marketing services
*myfanbox.com                # 27 August 2014


*postageapp.com              # 25 November 2014 : commercial email
sender


*respread.com
*respread.net
*rk-mail.com                 # Centos abuse
*rnmk.com                    # Oracle spam for Nikon
*rsbn2.com
*rsgg1.com
*rsgog.com
*rsgsv.net
*rsp-apn2.com
*rsp-apn8.com                # Reasonables 01 Dec 2015
*rspmail-apn1.com            # 4 May 2016
*rspmail-apn2.com            # 17 May 2016
*rspmail-apn3.com            # 14 May 2016
*rspmail-apn4.com
*rspread.net


*spread2.com
*spread2.net
*sslsonar.org                # scanner.sslsonar.org
*strim.net.ua                # 13 Mar 2016.


etc.

--
Regards,

Paul.
England, EU.      England's place is in the European Union.