From owner-freebsd-questions@freebsd.org Thu Jan 12 04:05:51 2017 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 02FCFCABD19 for ; Thu, 12 Jan 2017 04:05:51 +0000 (UTC) (envelope-from kurt.buff@gmail.com) Received: from mail-it0-x22d.google.com (mail-it0-x22d.google.com [IPv6:2607:f8b0:4001:c0b::22d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id BA9AE1085 for ; Thu, 12 Jan 2017 04:05:50 +0000 (UTC) (envelope-from kurt.buff@gmail.com) Received: by mail-it0-x22d.google.com with SMTP id x2so1306697itf.1 for ; Wed, 11 Jan 2017 20:05:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to; bh=ZcB3VWaGy8eeMqO8Oh1pyycsoiOL0dspGdC2lbnE+sg=; b=KLuoKX5pcT27q+CYHj7NYjiFs2qg/DiyIfIMif6B2gmoxpx0/+e8/EwxY+usyq9+MQ tH3vrErGnB8jeN9UuGOuXzuA32TxbUO3OBp57aRAmWn7Os5xz1tFSi6f8anLor1QBat2 eVPft2vWxyqbfrJ8Vj6xVENOkbA0OuRguIiG9UYLc57vvaVdeGKPgIqoT6LMdKmpSydn DD/3vuROPH+NqDgNlwxgZ4rBWc9azeN1QdH4pCFuk4VjcOXIfSFDA9CFq7eXbxagTKhn kHUPTCrYiVsS4QAfmvRO9OkfrBLTU+qna1lOZHwDMuYensTETOBV0rw9Fg2/oK7xgO86 ZmUA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to; bh=ZcB3VWaGy8eeMqO8Oh1pyycsoiOL0dspGdC2lbnE+sg=; b=hQqfqIFWi8XlQ5oDoJQqiqYkNur8IOvRr5hr47OFVf4GLk3U2CiG3mpLExl/uuQ+ls oQeHn4hcJ17wTVIWRfpcxZ3j4p1ISKheQ5hFt+Tehsdn7TVTRGZ71gFwx/J4ZYdIaOvK SmC2X4IcxddnYZ4bF4xnLoeV322JEiDP4D1J2aKgE3cL/cwsAH7lFFR7/S1m3VADDpQ4 XXf1qtbaoczcst+xarnxsCCLS4LO9PM8kirM2FghzCanM71ncz1zvey2eaYeDSQOk85p uv6R5cQGCkqreEt2udoQAEakwJsAxVN1Ayva6PuYJ6FGu86qtzqkR0qEE8m+AO7j3gaS 32MQ== X-Gm-Message-State: AIkVDXJkzlJ5OEmDdgCVSaOBgBAbTPIjfFlvVjYQyh3NyvJtBgN1hcpRb77VGoJZG5/Bv8l3dOo/ZO8lC7Xvow== X-Received: by 10.36.88.65 with SMTP id f62mr8688050itb.89.1484193949997; Wed, 11 Jan 2017 20:05:49 -0800 (PST) MIME-Version: 1.0 Received: by 10.79.125.132 with HTTP; Wed, 11 Jan 2017 20:05:49 -0800 (PST) In-Reply-To: References: <2463a238-e10f-e81d-cab1-5a7eaf774590@pinyon.org> <20170111210507.2dc39818c6e9d439abb21ee6@sohara.org> <8016faa3-5af4-6c2d-acdf-9b02f7f1afc8@pinyon.org> From: Kurt Buff Date: Wed, 11 Jan 2017 20:05:49 -0800 Message-ID: Subject: Re: spamassassin not lethal anymore To: "freebsd-questions@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Jan 2017 04:05:51 -0000 On Wed, Jan 11, 2017 at 5:34 PM, Russell L. Carter wrote: > On 01/11/17 17:24, Kurt Buff wrote: >> >> Snippety snip... >> >> On Wed, Jan 11, 2017 at 4:13 PM, Russell L. Carter >> wrote: >>> >>> On 01/11/17 14:05, Steve O'Hara-Smith wrote: >>>> >>>> >>>> On Wed, 11 Jan 2017 13:45:47 -0700 >>>> "Russell L. Carter" wrote: >>>> most of it botnet sourced. I've pretty much eliminated it now by a >>>> combination of installing dcc and razor plugins to spamassassin (reduced >>>> the spam getting through by 70% or so) and adding a backup MX with a >>>> free >>>> service that only accepts messages to relay when the primary is down >>>> (it's >>>> amazing how much spam stopped coming in when I did that). >>>> >>> >>> I'm not sure what you mean here, can you elaborate a bit more? I can >>> do anything I like with my MX hosts so I'm game. I *think* I'm >>> already doing that. I have multiple domains, and so I have a primary >>> MX and a couple of backup MX hosts (one of which is effectively a >>> passive dovecot replicator, lordy that works fantastic). The backup >>> MX hosts are lower priority than the primary. Are you doing something >>> different? >> >> >> A secondary MX that refuses mail when the primary is up and running >> foils one of the favorite tactics of spammers - they will often target >> the secondary MX because those are often not as up to date with >> anti-spam measures. Most spambots try one MX, one time only. >> >> Many spambots will try that secondary MX, get refused with a 4xx >> error, and not bother to try the primary MX at all. >> >> It can be a big win, in the right situation. > > > Ah. Awesome. How do I do that? > > Russell As Steve O'Hara Smith wrote, there are free services that can do that. Perhaps he can mention which one he uses. But, if you have a spare public IP address, I suppose you could set up another MX with postfix and have it respond to all inbound with a 4xx. Greylisting, as someone else mentioned, is probably a really good alternative - that responds with a temp fail message, and again most spambots won't try again. Kurt