From owner-freebsd-hackers Fri Sep 5 21:34:24 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id VAA20517 for hackers-outgoing; Fri, 5 Sep 1997 21:34:24 -0700 (PDT) Received: from rocky.mt.sri.com (rocky.mt.sri.com [206.127.76.100]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id VAA20493 for ; Fri, 5 Sep 1997 21:34:14 -0700 (PDT) Received: (from nate@localhost) by rocky.mt.sri.com (8.7.5/8.7.3) id WAA11474; Fri, 5 Sep 1997 22:34:07 -0600 (MDT) Date: Fri, 5 Sep 1997 22:34:07 -0600 (MDT) Message-Id: <199709060434.WAA11474@rocky.mt.sri.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: "Jordan K. Hubbard" Cc: hackers@freebsd.org Subject: Re: A quick note to those without DNS resolvable mail hosts. In-Reply-To: <26041.873509860@time.cdrom.com> References: <26041.873509860@time.cdrom.com> X-Mailer: VM 6.29 under 19.15 XEmacs Lucid Sender: owner-freebsd-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk > > In order to combat the absolute flood of spam which has been coming > into my mailbox lately, I've gone to more aggressive sendmail filtering > which: > > A) Blocks mail from you if you don't have a valid hostname > (this means that I've been bouncing mail from hosts like > "moose.mindspring.com" and "yokota.mech.kobe-u.ac.jp", > both of which probably represent actual legitimate > attempts to send me mail). Quick question. If I have a valid 'MX' record, is that good enough? My email comes from 'user@mt.sri.com', and there is no machine 'mt.sri.com', since it represents all the hosts in my domain and not a particular host in general. However, my email is correctly MX'd so that email will be correctly sent to the correct machine. This is 'the way it should be' for organizations where email may come from any number of machines, but should be sent to a specific (aka. centralized) machine. This is necessary for both sanity as well as security, since it means that I can setup *one* incoming mail server which is secure, and not allow connections to the other boxes in my domain from external hosts. Nate