From owner-freebsd-stable@FreeBSD.ORG Sat Jan 27 15:26:07 2007 Return-Path: X-Original-To: freebsd-stable@freebsd.org Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 3A07D16A402 for ; Sat, 27 Jan 2007 15:26:07 +0000 (UTC) (envelope-from joao@matik.com.br) Received: from msrv.matik.com.br (msrv.matik.com.br [200.152.83.14]) by mx1.freebsd.org (Postfix) with ESMTP id 9B88E13C483 for ; Sat, 27 Jan 2007 15:26:06 +0000 (UTC) (envelope-from joao@matik.com.br) Received: from anc ([200.152.88.34]) by msrv.matik.com.br (8.13.8/8.13.1) with ESMTP id l0RFQ5Vq066617; Sat, 27 Jan 2007 13:26:05 -0200 (BRST) (envelope-from joao@matik.com.br) From: JoaoBR Organization: Infomatik To: Roland Smith Date: Sat, 27 Jan 2007 13:25:52 -0200 User-Agent: KMail/1.9.4 References: <8a20e5000701240903q35b89e14k1ab977df62411784@mail.gmail.com> <45BB6296.1080106@pingle.org> <20070127150422.GA96846@slackbox.xs4all.nl> In-Reply-To: <20070127150422.GA96846@slackbox.xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline Message-Id: <200701271325.53070.joao@matik.com.br> X-Virus-Scanned: ClamAV version 0.88.4, clamav-milter version 0.88.4 on msrv.matik.com.br X-Virus-Status: Clean Cc: freebsd-stable@freebsd.org Subject: Re: Loosing spam fight X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 27 Jan 2007 15:26:07 -0000 On Saturday 27 January 2007 13:04, Roland Smith wrote: > > That's not a bonus. Think about it. Sending a message twice will cut the > spammer's mail delivery rate at least in half. > nobody cares about this, what counts is the hit rate, more you get delivere= d=20 merrier the return, that means more you reject more is send in order to get= =20 the desired profit > > Greylisting is a decent idea, but it seems to me that it's just another > > tool in the ongoing arms race against spammers. > > There is no silver bullit. But currently greylisting seems to stop > around 95% of spam, and a lot of e-mail based virusus too. See the link > above. this number is absolute not true, depending on how popular your mail server= is=20 or your domain names are you get a constant rate hammered into you network= =20 and it does not matter if you use greylists or whatever *rejecting* method the only real effective method is delaying the connection, counting on that= =20 the sending server is timing out without getting response. A correct smtp=20 server will wait enough but spammer servers/programms are not waiting a=20 minute for delivering each message > > It may work for a while, but eventually they'll catch on and it will > > only cause unnecessary delays for legitimate mail. > > Since the "cure" for greylisting involves at least cutting the spam rate > in half, I doubt many spammers will adopt it. > there is no cure=20 spammer will stop adopting when people stop getting horny or greedy so I gu= ess=20 your approach is failing sadly :) > As for delaying legitimate mail, SMTP is considered an unreliable > transport. That is why RFC 821 allows for temporary failures. If you > want to contact someone about something that is time-critical, you > shouldn't use e-mail anyway. people, as normal internet users, which are the main spammer target, do use= =20 email as it is and they do not care about *why* the message is not coming i= n=20 but they care about that it is *not* coming in within a acceptable time spa= n=20 of some minutes or so - which by the way is the correct thinking =2D-=20 Jo=E3o A mensagem foi scaneada pelo sistema de e-mail e pode ser considerada segura. Service fornecido pelo Datacenter Matik https://datacenter.matik.com.br