From owner-freebsd-stable@FreeBSD.ORG Fri Aug 27 09:28:32 2010 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id D23E7106564A for ; Fri, 27 Aug 2010 09:28:32 +0000 (UTC) (envelope-from jdc@koitsu.dyndns.org) Received: from qmta07.emeryville.ca.mail.comcast.net (qmta07.emeryville.ca.mail.comcast.net [76.96.30.64]) by mx1.freebsd.org (Postfix) with ESMTP id B57708FC08 for ; Fri, 27 Aug 2010 09:28:32 +0000 (UTC) Received: from omta15.emeryville.ca.mail.comcast.net ([76.96.30.71]) by qmta07.emeryville.ca.mail.comcast.net with comcast id zMUY1e0031Y3wxoA7MUYTX; Fri, 27 Aug 2010 09:28:32 +0000 Received: from koitsu.dyndns.org ([98.248.41.155]) by omta15.emeryville.ca.mail.comcast.net with comcast id zMUW1e0013LrwQ28bMUWHG; Fri, 27 Aug 2010 09:28:31 +0000 Received: by icarus.home.lan (Postfix, from userid 1000) id 1C8AE9B425; Fri, 27 Aug 2010 02:28:30 -0700 (PDT) Date: Fri, 27 Aug 2010 02:28:30 -0700 From: Jeremy Chadwick To: Ronald Klop Message-ID: <20100827092830.GA21076@icarus.home.lan> References: <4C74261A.4000401@icyb.net.ua> <20100827082128.07538364425@drugs.dv.isc.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Cc: freebsd-stable@freebsd.org, Andriy Gapon Subject: Re: cname replace in mail address? [off-topic] (Re: Attn Ronald Klop) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 27 Aug 2010 09:28:32 -0000 On Fri, Aug 27, 2010 at 11:22:05AM +0200, Ronald Klop wrote: > Mandatory? I'm googling, but can't find a document that declares it > mandatory and only sendmail seems to do it. > I think it is lame to use DNS info to rewrite e-mail addresses, but > the person who made it 'mandatory' will have good reasons for it. > > Does somebody have a pointer to the specs about this? First hit on Google: http://www.ferris.com/2008/09/08/why-you-shouldnt-mix-cname-and-mx/ Bottom line: don't use CNAMEs, ever, unless you know ***exactly*** what you're doing. It's been like this for a very long time. -- | Jeremy Chadwick jdc@parodius.com | | Parodius Networking http://www.parodius.com/ | | UNIX Systems Administrator Mountain View, CA, USA | | Making life hard for others since 1977. PGP: 4BD6C0CB |