From owner-freebsd-questions@FreeBSD.ORG Fri Jul 13 20:12:13 2007 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 0C80E16A405 for ; Fri, 13 Jul 2007 20:12:13 +0000 (UTC) (envelope-from jeffrey@goldmark.org) Received: from out2.smtp.messagingengine.com (out2.smtp.messagingengine.com [66.111.4.26]) by mx1.freebsd.org (Postfix) with ESMTP id D87D813C4AA for ; Fri, 13 Jul 2007 20:12:12 +0000 (UTC) (envelope-from jeffrey@goldmark.org) Received: from compute1.internal (compute1.internal [10.202.2.41]) by out1.messagingengine.com (Postfix) with ESMTP id 76CF18562; Fri, 13 Jul 2007 16:12:12 -0400 (EDT) Received: from heartbeat2.messagingengine.com ([10.202.2.161]) by compute1.internal (MEProxy); Fri, 13 Jul 2007 16:12:12 -0400 X-Sasl-enc: Z8qmfZW2+x5/yYtBziisYtvjoPELapTswsBSAqzEXzac 1184357532 Received: from [10.1.10.136] (n114.ewd.goldmark.org [72.64.118.114]) by mail.messagingengine.com (Postfix) with ESMTP id 27EE81F0E3; Fri, 13 Jul 2007 16:12:12 -0400 (EDT) In-Reply-To: <200707130730.l6D7U6v9086226@banyan.cs.ait.ac.th> References: <200707130730.l6D7U6v9086226@banyan.cs.ait.ac.th> Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Message-Id: <47E045D4-44AB-44B8-A358-59ECA482CF81@goldmark.org> Content-Transfer-Encoding: 7bit From: Jeffrey Goldberg Date: Fri, 13 Jul 2007 15:12:10 -0500 To: Olivier Nicole X-Mailer: Apple Mail (2.752.2) Cc: freebsd-questions@freebsd.org Subject: Re: Transparent email proxy X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 13 Jul 2007 20:12:13 -0000 On Jul 13, 2007, at 2:30 AM, Olivier Nicole wrote: > As an ISP, or the person in charge of a large organisation, have you > ever set-up a transparent email redirection: all outgoing email would > be proceeded to an outgoing server in order to check for virus, spam, > whatever. I've done this non-transparently many times. At the perimeter firewalls the only traffic to port 25 which was allowed was from our official outgoing mail servers. With the firewall, it is easy to make the use of the outgoing mail hub compulsory. Is there some reason beyond that that you want to do things transparently? -j -- Jeffrey Goldberg http://www.goldmark.org/jeff/