Re: [xmail] Enabling SPF howto?
In article 498198a5.1020...@amitrader.com, r...@amitrader.com (Ralf) wrote: Hmm... I think there are some misunderstandings here. Possibly. My understanding was that SPF stopped emails coming from what was apparently the wrong server for the domain. e.g. my email address is g...@bainb.co.uk. If I send any email it has that 'From' address, no matter which server I send it through. If I send this via the server where my domain is registered - in my case my own server, but previously the server belonging to my ISP - then it is accepted. However if I send an email with my 'From' address (g...@bainb.co.uk) via my cellphone company's server then it will be rejected by the recipient as that server is not in my domain's DNS record. Note that I have to use their server if I send an email via my phone (at least that's true unless I use my own webmail). From the OpenSPF website: When an AOL user sends mail to you, an email server that belongs to AOL connects to an email server that belongs to you. AOL uses SPF to publish the addresses of its email servers. When the message comes in, your email servers can tell if the server on the other end of the connection belongs to AOL or not. Have I misunderstood? Gary. ___ xmail mailing list xmail@xmailserver.org http://xmailserver.org/mailman/listinfo/xmail
Re: [xmail] Enabling SPF howto?
On Thu, 29 Jan 2009, Ralf wrote: Hmm... I think there are some misunderstandings here. SPF is intended for servers only, not for end users. If the user sends his mail via his mail server then the receiving mail server just checks in the DNS DB whether the sending mail server (not the user!) is really permitted to send mails for that domain. Nothing less, nothing more. The reason why SPF tanked, was exactly that there are many real case scenarios where you cannot fix that bill. SPF is/was used, unsuccesfully as it is clear at this point, to block SPAM. That was the whole point of it. Reject emails based on forged/fake return address. Besides, every anti-SPAM solution that in order to be successful, expect that all the SMTP servers in the world change something, is doomed from day 1. - Davide ___ xmail mailing list xmail@xmailserver.org http://xmailserver.org/mailman/listinfo/xmail
Re: [xmail] Enabling SPF howto?
On Thu, 29 Jan 2009, Ralf wrote: I'm trying to switch from qmail to xmail. There I had SPF activated and would like to use SPF also in xmail. I saw that there is a perl script for SPF (http://www.xmailserver.org/xm-spf.pl), but how do I integrate it into xmail? Suggestion. Leave SPF alone. Nobody is using it and its contribution on SPAM-cutting on my servers was totally irrelevant WRT greylisting and RBLs. The whole SPF project tanked, badly. - Davide ___ xmail mailing list xmail@xmailserver.org http://xmailserver.org/mailman/listinfo/xmail
Re: [xmail] Enabling SPF howto?
Davide Libenzi wrote: On Thu, 29 Jan 2009, Ralf wrote: I'm trying to switch from qmail to xmail. There I had SPF activated and would like to use SPF also in xmail. I saw that there is a perl script for SPF (http://www.xmailserver.org/xm-spf.pl), but how do I integrate it into xmail? Suggestion. Leave SPF alone. Nobody is using it and its contribution on SPAM-cutting on my servers was totally irrelevant WRT greylisting and RBLs. The whole SPF project tanked, badly. Sorry Davide, but I _must_ use SPF. That's the policy here. I would very much appreciate it if you could show me how to activate SPF in xmail (maybe you should include this info into the comment header of the xm-spf.pl file). Best Regards, Ralf ___ xmail mailing list xmail@xmailserver.org http://xmailserver.org/mailman/listinfo/xmail
Re: [xmail] Enabling SPF howto?
fred wrote: It might help you but this is the script that I have made / use: http://xmailforum.homelinux.net/index.php?showtopic=4260 Tnanks fred, but per our security policy I can use only C/C++ source and bash or perl scripts. But especially php and python aren't allowed on the Linux boxes where our mail servers run. Best Regards, Ralf -Original Message- From: xmail-boun...@xmailserver.org [mailto:xmail-boun...@xmailserver.org] On Behalf Of Ralf Sent: 28 janvier 2009 20:43 To: XMail Users Mailing List Subject: Re: [xmail] Enabling SPF howto? Davide Libenzi wrote: On Thu, 29 Jan 2009, Ralf wrote: I'm trying to switch from qmail to xmail. There I had SPF activated and would like to use SPF also in xmail. I saw that there is a perl script for SPF (http://www.xmailserver.org/xm-spf.pl), but how do I integrate it into xmail? Suggestion. Leave SPF alone. Nobody is using it and its contribution on SPAM-cutting on my servers was totally irrelevant WRT greylisting and RBLs. The whole SPF project tanked, badly. Sorry Davide, but I _must_ use SPF. That's the policy here. I would very much appreciate it if you could show me how to activate SPF in xmail (maybe you should include this info into the comment header of the xm-spf.pl file). Best Regards, Ralf ___ xmail mailing list xmail@xmailserver.org http://xmailserver.org/mailman/listinfo/xmail
Re: [xmail] Enabling SPF howto?
On Thu, 29 Jan 2009, Ralf wrote:
fred wrote:
It might help you but this is the script that I have made / use:
http://xmailforum.homelinux.net/index.php?showtopic=4260
Tnanks fred,
but per our security policy I can use only C/C++ source and
bash or perl scripts. But especially php and python aren't allowed
on the Linux boxes where our mail servers run.
I really don't remember. I only briefly used it, given its complete
failure to stop anything.
You prolly want to use filters.post-rcpt.tab with something like:
!aex[TAB]PATH/xm-spf.pl[TAB]--ip[TAB]$(REMOTEADDR)[TAB] \
--sender[TAB]$(FROM)[TAB]--rcpt-to[TAB]$(CRCPT)
Where [TAB] is the *real* TAB character, and that's a single line (' \ ')
trimmed.
I cannot ensure you any success though :)
- Davide
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Re: [xmail] Enabling SPF howto?
Davide Libenzi wrote:
On Thu, 29 Jan 2009, Ralf wrote:
fred wrote:
It might help you but this is the script that I have made / use:
http://xmailforum.homelinux.net/index.php?showtopic=4260
Tnanks fred,
but per our security policy I can use only C/C++ source and
bash or perl scripts. But especially php and python aren't allowed
on the Linux boxes where our mail servers run.
I really don't remember. I only briefly used it, given its complete
failure to stop anything.
You prolly want to use filters.post-rcpt.tab with something like:
!aex[TAB]PATH/xm-spf.pl[TAB]--ip[TAB]$(REMOTEADDR)[TAB] \
--sender[TAB]$(FROM)[TAB]--rcpt-to[TAB]$(CRCPT)
Where [TAB] is the *real* TAB character, and that's a single line (' \ ')
trimmed.
I cannot ensure you any success though :)
Thanks, will try it out.
Here are some examples of SPF catches by my other mail server.
It shows that SPF indeed catches spammers who misusingly
use the same domain name of the destination mail server or
of the To-adress for their own machine to trick the mail server
to believe he is from the same domain...
SPF is not a spam solution, it just checks whether the
sending machine has been authorized (via DNS SPF/TXT record)
to send mail for that domain. So it catches those spammers
who illegally use other domain names in their own hostname / mail domain name...
Log excerpt:
Received-SPF: softfail (srv3.amitrader.com: transitioning SPF record at blue.plala.or.jp does not designate 92.39.220.216 as
permitted sender)
Received-SPF: softfail (srv3.amitrader.com: transitioning SPF record at dvdownunder.com.au does not designate 91.124.168.23 as
permitted sender)
Received-SPF: softfail (srv3.amitrader.com: transitioning SPF record at msn.com
does not designate 213.21.33.60 as permitted sender)
The return values (above softfail; there are some more) can help
to decide whether to accept or reject mail from such a sender...
In the above cases my mail server rejected to accept mail from those spammers.
BTW, here is your own SPF entry: :-)
Received-SPF: pass (srv3.amitrader.com: SPF record at xmailserver.org
designates 64.71.152.41 as permitted sender)
Received: (qmail 23732 invoked from network); 29 Jan 2009 03:18:32 +0100
Received: from x35.xmailserver.org (64.71.152.41)
by srv3.amitrader.com with (DHE-RSA-AES256-SHA encrypted) SMTP; 29 Jan 2009
03:18:32 +0100
Received-SPF: pass (srv3.amitrader.com: SPF record at xmailserver.org
designates 64.71.152.41 as permitted sender)
Received: from x35.xmailserver.org ([:::127.0.0.1]:50052)
by x35.xmailserver.org with [XMail 1.26 ESMTP Server]
id S2CB6CA for r...@amitrader.com from
xmail-boun...@xmailserver.org;
Wed, 28 Jan 2009 21:17:44 -0500
X-AuthUser: davi...@xmailserver.org
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Wed, 28 Jan 2009 21:17:29 -0500
Date: Wed, 28 Jan 2009 18:17:28 -0800 (PST)
From: Davide Libenzi davi...@xmailserver.org
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Subject: Re: [xmail] Enabling SPF howto?
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Re: [xmail] Enabling SPF howto?
Besides the mentioned perl module there is also a native C library
for SPF/SRS (and also a prebuilt package in the Debian repository),
called libspf2, so it would IMO make sense to add native
SPF capability into xmail.
http://packages.debian.org/unstable/source/libspf2
Source Package: libspf2 (1.2.9-1)
Homepage www.libspf2.org
The following binary packages are built from this source package:
libspf2-2
library for validating mail senders with SPF
libspf2-dev
Header and development libraries for libspf2
spfquery
query SPF (Sender Policy Framework) to validate mail senders
The Sender Policy Framework (SPF) is one part of the SPF/SRS protocol pair.
SPF allows email systems such as Sendmail, Postfix, Exim, Zmailer and
MS Exchange to check SPF records and make sure that the email is authorized
by the domain name that it is coming from. This prevents email forgery,
commonly used by spammers, scammers and email viruses/worms.
This package contains simple utilities that use libspf2 to test and query SPF
records.
And here is a list of mail servers with SPF-support:
http://www.openspf.org/Implementations
Ralf wrote:
Davide Libenzi wrote:
On Thu, 29 Jan 2009, Ralf wrote:
fred wrote:
It might help you but this is the script that I have made / use:
http://xmailforum.homelinux.net/index.php?showtopic=4260
Tnanks fred,
but per our security policy I can use only C/C++ source and
bash or perl scripts. But especially php and python aren't allowed
on the Linux boxes where our mail servers run.
I really don't remember. I only briefly used it, given its complete
failure to stop anything.
You prolly want to use filters.post-rcpt.tab with something like:
!aex[TAB]PATH/xm-spf.pl[TAB]--ip[TAB]$(REMOTEADDR)[TAB] \
--sender[TAB]$(FROM)[TAB]--rcpt-to[TAB]$(CRCPT)
Where [TAB] is the *real* TAB character, and that's a single line (' \
') trimmed.
I cannot ensure you any success though :)
Thanks, will try it out.
Here are some examples of SPF catches by my other mail server.
It shows that SPF indeed catches spammers who misusingly
use the same domain name of the destination mail server or
of the To-adress for their own machine to trick the mail server
to believe he is from the same domain...
SPF is not a spam solution, it just checks whether the
sending machine has been authorized (via DNS SPF/TXT record)
to send mail for that domain. So it catches those spammers
who illegally use other domain names in their own hostname / mail domain
name...
Log excerpt:
Received-SPF: softfail (srv3.amitrader.com: transitioning SPF record at
blue.plala.or.jp does not designate 92.39.220.216 as permitted sender)
Received-SPF: softfail (srv3.amitrader.com: transitioning SPF record at
dvdownunder.com.au does not designate 91.124.168.23 as permitted sender)
Received-SPF: softfail (srv3.amitrader.com: transitioning SPF record at
msn.com does not designate 213.21.33.60 as permitted sender)
The return values (above softfail; there are some more) can help
to decide whether to accept or reject mail from such a sender...
In the above cases my mail server rejected to accept mail from those
spammers.
BTW, here is your own SPF entry: :-)
Received-SPF: pass (srv3.amitrader.com: SPF record at xmailserver.org
designates 64.71.152.41 as permitted sender)
Received: (qmail 23732 invoked from network); 29 Jan 2009 03:18:32 +0100
Received: from x35.xmailserver.org (64.71.152.41)
by srv3.amitrader.com with (DHE-RSA-AES256-SHA encrypted) SMTP; 29 Jan
2009 03:18:32 +0100
Received-SPF: pass (srv3.amitrader.com: SPF record at xmailserver.org
designates 64.71.152.41 as permitted sender)
Received: from x35.xmailserver.org ([:::127.0.0.1]:50052)
by x35.xmailserver.org with [XMail 1.26 ESMTP Server]
id S2CB6CA for r...@amitrader.com from
xmail-boun...@xmailserver.org;
Wed, 28 Jan 2009 21:17:44 -0500
X-AuthUser: davi...@xmailserver.org
Received: from alien.or.mcafeemobile.com
by x35.xmailserver.org with [XMail 1.26 ESMTP Server]
id S2CB6C7 for xmail@xmailserver.org from
davi...@xmailserver.org;
Wed, 28 Jan 2009 21:17:29 -0500
Date: Wed, 28 Jan 2009 18:17:28 -0800 (PST)
From: Davide Libenzi davi...@xmailserver.org
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To: XMail Users Mailing List xmail@xmailserver.org
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References: 4980fb23.6070...@amitrader.com
alpine.deb.1.10.0901281704560.21...@alien.or.mcafeemobile.com
49810994.4020...@amitrader.com
004901c981b3$9abf30c0$d03d92...@com
49810ea6.4090...@amitrader.com
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Subject: Re: [xmail] Enabling SPF howto?
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