From owner-freebsd-questions@FreeBSD.ORG Mon Jun 7 17:12:42 2004 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 B218116A4D0 for ; Mon, 7 Jun 2004 17:12:42 +0000 (GMT) Received: from mail.mi.celestial.com (dagney.celestial.com [192.136.111.7]) by mx1.FreeBSD.org (Postfix) with ESMTP id 7F5CA43D46 for ; Mon, 7 Jun 2004 17:12:42 +0000 (GMT) (envelope-from bill@celestial.com) Received: by mail.mi.celestial.com (Postfix, from userid 203) id E185711E88C; Mon, 7 Jun 2004 10:12:41 -0700 (PDT) Date: Mon, 7 Jun 2004 10:12:41 -0700 From: Bill Campbell To: freebsd-questions@freebsd.org Message-ID: <20040607171241.GA11891@alexis.mi.celestial.com> Mail-Followup-To: freebsd-questions@freebsd.org References: <20040607085739.352eba17.wmoran@potentialtech.com> <200406071511.i57FB3Ol073942@adsl-68-76-19-75.dsl.klmzmi.ameritech.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200406071511.i57FB3Ol073942@adsl-68-76-19-75.dsl.klmzmi.ameritech.net> User-Agent: Mutt/1.4.2.1i 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 Reply-To: freebsd@celestial.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Jun 2004 17:12:42 -0000 On Mon, Jun 07, 2004, Lucas Holt wrote: > > >Just make sure they are truly dynamic ips. Many people block ips identified >as "DSL" connections. Those are not necessarily dynamic ip based.... Some of the largest ISPs in the country, including AOL, are blocking what they consider ``residential dsl'' in an attempt to stem the flood of spam and worms that are propagated through owned Microsoft Windows machines on broadband connections. The majority of spam today is sent through zombified Windows boxes that either are open proxies or have spammer software installed on them that ``calls home'' to the spammer's servers to get spam and lists of addresses to deliver. Several months ago I installed a Linux server at one of our customer sites running postfix on a QWest dynamic DSL line, and found that AOL was blocking their SMTP connection with an immediate message saying that they refused connections from ``residential'' DSL connections, and disconnecting immediately without presenting an SMTP header. I redirected all the traffic to AOL through one of our mail servers here using the postfix ``transport'' mechanism, and had the customer order the smallest fixed IP block that QWest offered. As soon as that block was working, their server could connect to AOL's servers without a problem, leading me to believe that AOL and QWest are co-operating to distinguish between the dynamic and fixed IP blocks. Bill -- INTERNET: bill@Celestial.COM Bill Campbell; Celestial Systems, Inc. UUCP: camco!bill PO Box 820; 6641 E. Mercer Way FAX: (206) 232-9186 Mercer Island, WA 98040-0820; (206) 236-1676 URL: http://www.celestial.com/ Memoirs -- Bill Clinton is getting $12 million for his memoirs, and his wife Hillary got $8 million for hers. That's $20 million for memories from two people who for eight years repeatedly testified they couldn't remember anything.