From owner-freebsd-questions@FreeBSD.ORG Fri Oct 12 20:12:27 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D31C416A417 for ; Fri, 12 Oct 2007 20:12:27 +0000 (UTC) (envelope-from peo@intersonic.se) Received: from neonpark.inter-sonic.com (neonpark.inter-sonic.com [212.247.8.98]) by mx1.freebsd.org (Postfix) with ESMTP id 9DD4913C468 for ; Fri, 12 Oct 2007 20:12:27 +0000 (UTC) (envelope-from peo@intersonic.se) X-Virus-Scanned: amavisd-new at inter-sonic.com Message-ID: <470FD526.302@intersonic.se> Date: Fri, 12 Oct 2007 22:12:22 +0200 From: Per olof Ljungmark Organization: Intersonic AB User-Agent: Thunderbird 2.0.0.6 (X11/20071009) MIME-Version: 1.0 To: Robin Becker References: <470F62F3.9040309@chamonix.reportlab.co.uk> <64D5573F-7C7F-404D-8928-E015D595A54C@goldmark.org> <470F874A.4080305@chamonix.reportlab.co.uk> <4AF1909B-6B25-49BC-9EC8-2DD35A352950@goldmark.org> <470FADC3.40102@chamonix.reportlab.co.uk> In-Reply-To: <470FADC3.40102@chamonix.reportlab.co.uk> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD_Questions FreeBSD_Questions , Jeffrey Goldberg Subject: Re: genuine bulk email X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Oct 2007 20:12:27 -0000 Robin Becker wrote: > Jeffrey Goldberg wrote: >> >> The checking will work fine with virtual domains. What matters is that >> >> DNS(rDNS(IP)) = IP = DNS(vhost) >> >> I think I've got that right. (It's a bit more complicated to state >> when MXes and multiple A records for the same name are considered, but >> this is the general idea.) >> This is your problem: Ass long as the reverse DNS for the sending IP does not resolve to an existing domain name you are fried. Fix that and you're all set. dig -x 217.196.247.135 ; <<>> DiG 9.3.3 <<>> -x 217.196.247.135 ;; global options: printcmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 28770 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;135.247.196.217.in-addr.arpa. IN PTR ;; AUTHORITY SECTION: 247.196.217.in-addr.arpa. 3600 IN SOA ns0.highspeedoffice.net. hostmaster.highspeedoffice.net. 2007061800 28800 7200 2419200 3600 ;; Query time: 56 msec ;; SERVER: 127.0.0.1#53(127.0.0.1) ;; WHEN: Fri Oct 12 22:09:13 2007 ;; MSG SIZE rcvd: 116