From owner-freebsd-questions Mon Mar 17 5:13:16 2003 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 A360B37B401 for ; Mon, 17 Mar 2003 05:13:14 -0800 (PST) Received: from pa-plum1b-166.pit.adelphia.net (pa-plum1b-122.pit.adelphia.net [24.53.161.122]) by mx1.FreeBSD.org (Postfix) with ESMTP id AFAF343F85 for ; Mon, 17 Mar 2003 05:13:13 -0800 (PST) (envelope-from wmoran@potentialtech.com) Received: from potentialtech.com (working [172.16.0.95]) by pa-plum1b-166.pit.adelphia.net (8.12.7/8.12.7) with ESMTP id h2HDDCTb010843; Mon, 17 Mar 2003 08:13:13 -0500 (EST) (envelope-from wmoran@potentialtech.com) Message-ID: <3E75C9D8.7000704@potentialtech.com> Date: Mon, 17 Mar 2003 08:12:56 -0500 From: Bill Moran User-Agent: Mozilla/5.0 (X11; U; FreeBSD i386; en-US; rv:1.2.1) Gecko/20030301 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Len Conrad Cc: freebsd-questions@freebsd.org Subject: Re: Sending mail to this list References: <48294587-583E-11D7-A325-000393BF3DE2@nmu.edu> <48294587-583E-11D7-A325-000393BF3DE2@nmu.edu> <5.2.0.9.0.20030317062946.01d82870@mail.go2france.com> In-Reply-To: <5.2.0.9.0.20030317062946.01d82870@mail.go2france.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG en Conrad wrote: > >> 1) The name the mailserver announces in it's HELO line must resolve via >> forward DNS. It doesn't matter to what, it just has to resolve. >> 2) The IP of the server must reverse resolve to something, it doesn't >> matter to what: except that that name is then tested on a forward >> DNS check, which must work. This is actually in the FAQ: http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/misc.html#FREEBSD-MAIL-BOUNCES >> My understanding is that these simple tests block thousands of spam >> emails per second! > > per hour, not per second. Either way ... pretty good statistics. >> The most common mistake I've seen people make is to add multiple reverse >> DNS records (when the machine has multiple forward DNS records) Most >> DNS servers will allow you to do this, but it doesn't work. > > DNS works fine having a set of PTR records per ip. What doesn't work is > that applications that query for PTR records only use the physically > first PTR record returned in the DNS responce packet, which, due to > caching, is uncontrollable. Which means that the system (effectively) doesn't work with multiple PTR records, which was all I was trying to say. -- Bill Moran Potential Technologies http://www.potentialtech.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message