From owner-freebsd-questions@FreeBSD.ORG Fri Aug 8 12:47:07 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8CD4C37B401 for ; Fri, 8 Aug 2003 12:47:07 -0700 (PDT) Received: from stelesys.com (www.stelesys.com [63.175.100.37]) by mx1.FreeBSD.org (Postfix) with ESMTP id 8C22C43FA3 for ; Fri, 8 Aug 2003 12:47:06 -0700 (PDT) (envelope-from jerry@syslog.org) Received: from ATLLAP130 (c-24-98-86-57.atl.client2.attbi.com [24.98.86.57]) (authenticated) by stelesys.com (8.11.5/8.11.2) with ESMTP id h78Jl5L86002 for ; Fri, 8 Aug 2003 15:47:05 -0400 (EDT) (envelope-from jerry@syslog.org) Message-ID: <009c01c35de5$d86f4290$100a0a0a@iss.net> From: "Jerry Bell" To: References: Date: Fri, 8 Aug 2003 15:47:05 -0400 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1158 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1165 Subject: Re: ISPs blocking SMTP connections from dynamic IP address space X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 08 Aug 2003 19:47:07 -0000 The problem with running an MTA on a "dynamic IP" is even a little more difficult than just dealing with the dnsbls. A while back on the exim users list: http://www.exim.org/pipermail/exim-users/Week-of-Mon-20030623/055733.html and http://www.exim.org/pipermail/exim-users/Week-of-Mon-20030630/055875.html was a discussion about how technically, the HELO address, forward dns and reverse dns should all match according to the smtp rfc. I'm not advocating one way or the other, but it brings up a good point - that the best way to run an MTA on a dsl or cable line is to either reflect off your ISP's mail server (unpopular as per the discussion so far) or to reflect off of some other 'legitimate' mail server, which is what I do. I'm fortunate enough to have a box on a colo network, so I'm able to control the server that my mail gets reflected off of, but I don't think that's the case for many people. What may be an option is to look for some form of ISP who provides that services and gives some control and visibility into the email flow. I'm not sure that that exists, but it can't be an expensive service to run (I see a business opportunity :) I think it really stinks that it has come to the point that people & companies have to take such steps to block "dynamic IP's", but I can see both sides of the arguement. Jerry