From owner-freebsd-isp@FreeBSD.ORG Mon Jul 26 20:36:13 2004 Return-Path: Delivered-To: freebsd-isp@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 7E7B516A4CE for ; Mon, 26 Jul 2004 20:36:13 +0000 (GMT) Received: from luke.wtconnect.com (luke.wtconnect.com [64.232.164.6]) by mx1.FreeBSD.org (Postfix) with ESMTP id BB67143D39 for ; Mon, 26 Jul 2004 20:36:12 +0000 (GMT) (envelope-from sblaydes@wtconnect.com) Received: from wtconnect.com (noc.wtconnect.com [64.232.164.10]) by luke.wtconnect.com (8.12.10/8.12.10) with ESMTP id i6QKa0tP076274; Mon, 26 Jul 2004 15:36:00 -0500 (CDT) (envelope-from sblaydes@wtconnect.com) Message-ID: <41056B3B.6050304@wtconnect.com> Date: Mon, 26 Jul 2004 15:36:11 -0500 From: Scott Blaydes User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6) Gecko/20040113 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Richard Kuhns , freebsd-isp@freebsd.org References: <41056580.3050007@wintek.com> In-Reply-To: <41056580.3050007@wintek.com> X-Enigmail-Version: 0.83.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-Spam-Status: No, hits=0.0 required=7.0 tests=none autolearn=no version=2.63 X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on luke.wtconnect.com X-Virus-Scanned: by amavisd-new Subject: Re: Question about virus/spam filtering for customers with mail servers X-BeenThere: freebsd-isp@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Internet Services Providers List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Jul 2004 20:36:13 -0000 Richard Kuhns wrote: > I'm hoping someone will be willing to share a better way to handle this. > > We offer virus/spam filtering for customers with their own mail servers. > We're currently implementing this by configuring the customer's firewall > to only accept smtp connections from our servers (all running sendmail > under FreeBSD 4), and the customer's MX records point to their server > first and our server(s) second and third. In most cases this works just > fine -- attempts by a mail server to deliver mail directly to the > customer fail, the mail server tries the secondary MX site (us), we > accept and filter the message and deliver it to the customer (or not). You could set up your FreeBSD boxes that are doing the scanning/filtering to be the primary and secondary MX for the domain and then use sendmail's mailertable to deliever the messages to the customers' servers. The mailertable will even let you ignore MX settings for the domain. Scott Blaydes