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<div>In addition to all that has been said, we covered building an Anti-SPAM filter at the past AfNOG workshop with Postfix and MailScanner. Should you wish to build one, there are instructions that should work for Debian or Ubuntu</div>
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<div><a href="http://ws.afnog.org/afnog2016/sse/index.html#postfix">http://ws.afnog.org/afnog2016/sse/index.html#postfix</a> </div>
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<div>Regards</div>
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<div>Kevin </div>
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<div>On 06/01/2017, 1:15 AM, "afnog on behalf of W W" <<a href="mailto:afnog-bounces@afnog.org">afnog-bounces@afnog.org</a> on behalf of
<a href="mailto:wanyalanabi@gmail.com">wanyalanabi@gmail.com</a>> wrote:</div>
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<p dir="ltr">Hi</p>
<p dir="ltr">Deploy Kerio Connect to listen on port on desperate box or on same Linux server. If behind a router, set destination Nat to forward to say port 26, Kerio Connect will listen on that, filter, score and forward mail to local host port 25.
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<p dir="ltr">Mail me if interested on further help. </p>
<div class="gmail_quote">On 22 Dec 2016 17:14, "Hezron Mwangi" <<a href="mailto:hmwangi@kenet.or.ke">hmwangi@kenet.or.ke</a>> wrote:<br type="attribution">
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<div>Dear Raphael,</div>
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<div>Maybe you can try building a mail filtering gateway that filters your emails before forwarding them to your mail server. In the mail filtering gateway you can run:<br>
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postfix as your MTA and ensure you do spf checking.<br>
postgrey which does greylisting.<br>
clamav which does virus scanning.<br>
spamassassin which scores emails and identifies spam.<br>
MailScanner which is a Powerful virus/spam scanning framework for mail gateways.<br>
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In addition you can try:</div>
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pyzor which is a Collaborative, networked system to detect and block spam.<br>
razor-agents which is a Distributed, collaborative, spam detection and filtering network.</div>
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<div>Kind regards,<br>
Hezron Mwangi.<br>
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<div><b>From: </b>"David Njuki" <<a href="mailto:njukey@gmail.com" target="_blank">njukey@gmail.com</a>><br>
<b>To: </b><a href="mailto:afnog@afnog.org" target="_blank">afnog@afnog.org</a><br>
<b>Sent: </b>Wednesday, 21 December, 2016 18:39:56<br>
<b>Subject: </b>Re: [afnog] I am getting porn spam emails<br>
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<div class="gmail_extra"><span class="m_-4740649536225944894gmail-im" style="font-size:12.800000190734863px">
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<span class="m_-4740649536225944894gmail-m_-8568858263233392987gmail-">> I am getting porn spam mail everyday in my mail server. Each email<br>
> are from different email addresses and domains. I have tried<br>
> creating a filter, and I have tried reporting them as spam. I need<br>
> to know how to stop receiving them.<br>
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</span>There is no perfect solution against spam. To avoid *reading* it, the<br>
best solution is a bayesian filter that you train. I use bogofilter<br>
and I'm very happy with it (very few false positives and few false<br>
negatives). But if you want to avoir *receiving* spam (because you<br>
want to save not only human attention, but also bandwidth), this is<br>
more complicated. Things that can help:<br>
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* reputable black lists. I say "reputable" because many lists are<br>
badly managed. (I use mostly two Spamhaus lists, <a href="http://sbl-xbl.spamhaus.org/" rel="noreferrer" target="_blank">sbl-xbl.spamhaus.org</a><br>
and <a href="http://xbl-xbl.spamhaus.org/" rel="noreferrer" target="_blank">xbl-xbl.spamhaus.org</a>.)<br>
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* greylisting (in my experience, it kills half of the spam before it<br>
reaches your email server (RFC 6647 is a good reading). Some people<br>
will claim it is useless because the spammers will adapt. Let them<br>
trust their theory, I trust my practice.<br>
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<div style="font-size:12.800000190734863px">As an addition to greylisting, also make sure you postfix does sender verification at smtp time. Many spammers fail this test. </div>
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<div style="font-size:12.800000190734863px">Check how to enable here <a href="http://www.postfix.org/ADDRESS_VERIFICATION_README.html#sender_always" target="_blank">http://www.postfix.org/<wbr>ADDRESS_VERIFICATION_README.<wbr>html#sender_always</a></div>
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