Date: Sat, 27 Jan 2007 13:25:52 -0200 From: JoaoBR <joao@matik.com.br> To: Roland Smith <rsmith@xs4all.nl> Cc: freebsd-stable@freebsd.org Subject: Re: Loosing spam fight Message-ID: <200701271325.53070.joao@matik.com.br> In-Reply-To: <20070127150422.GA96846@slackbox.xs4all.nl> References: <8a20e5000701240903q35b89e14k1ab977df62411784@mail.gmail.com> <45BB6296.1080106@pingle.org> <20070127150422.GA96846@slackbox.xs4all.nl>
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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
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