From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Delivered-To: caml-list@yquem.inria.fr Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by yquem.inria.fr (Postfix) with ESMTP id 8749DBCA8 for ; Thu, 31 Mar 2005 15:35:08 +0200 (CEST) Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id j2VDZ7K7021159 for ; Thu, 31 Mar 2005 15:35:07 +0200 Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id PAA02597 for ; Thu, 31 Mar 2005 15:35:07 +0200 (MET DST) Received: from laposte.rennes.enst-bretagne.fr (laposte.rennes.enst-bretagne.fr [192.44.77.17]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id j2VDZ64u021153; Thu, 31 Mar 2005 15:35:06 +0200 Received: from givry.rennes.enst-bretagne.fr (givry.rennes.enst-bretagne.fr [193.52.74.194]) by laposte.rennes.enst-bretagne.fr (8.11.6p2/8.11.6/2003.04.01) with ESMTP id j2VDZ0H17667; Thu, 31 Mar 2005 15:35:00 +0200 Received: from givry.rennes.enst-bretagne.fr (localhost.rennes.enst-bretagne.fr [127.0.0.1]) by givry.rennes.enst-bretagne.fr (8.13.1/8.13.1) with ESMTP id j2VDZ0v6069029; Thu, 31 Mar 2005 15:35:01 +0200 (CEST) (envelope-from dupont@givry.rennes.enst-bretagne.fr) Message-Id: <200503311335.j2VDZ0v6069029@givry.rennes.enst-bretagne.fr> From: Francis Dupont To: Eijiro Sumii Cc: caml-list@inria.fr, Xavier.Leroy@inria.fr, webmaster@brion.inria.fr Subject: Re: webmaster@caml.inria.fr is not a "legal" mail address In-reply-to: Your message of Thu, 31 Mar 2005 08:05:20 CDT. <20050331.080520.68550579.eijiro_sumii@anet.ne.jp> Date: Thu, 31 Mar 2005 15:35:00 +0200 Sender: Francis.Dupont@enst-bretagne.fr X-Virus-Scanned: by amavisd-milter (http://amavis.org/) at enst-bretagne.fr X-Miltered: at nez-perce with ID 424BFC8B.001 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Miltered: at nez-perce with ID 424BFC8A.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; literals:01 rewrites:01 grrr:01 imho:01 ...:98 821:98 ...:98 821:98 wrote:01 node:01 node:01 dmitry:01 rfc:02 rfc:02 caml:02 X-Spam-Checker-Version: SpamAssassin 3.0.2 (2004-11-16) on yquem.inria.fr X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.2 X-Spam-Level: In your previous mail you wrote: From: Francis Dupont > => aliases (CNAME left parts) are legal in mail addresses. But RFC 1123 says as below, for example...? => you mix up the MTA (which canonizes when it can *) and the MUA (which should accept any valid name). (* in RFC 821 section 3.7, not in RFC 2821 which was written after a real DNS practice). http://www.exim.org/pipermail/exim-users/Week-of-Mon-20030203/049446.html => you still mix up MTAs and MUAs. In fact, you suggest *your* MTA is wrong (:-)! (I wonder what Dmitry meant by "webmaster@caml.inria.fr is not routable"...) => me too. ---------------------------------------------------------------------- 5.2.2 Canonicalization: RFC-821 Section 3.1 => note this is in section 3.7, not 3.1 The domain names that a Sender-SMTP sends in MAIL and RCPT commands MUST have been "canonicalized," i.e., they must be fully-qualified principal names or domain literals, not nicknames or domain abbreviations. A canonicalized name either identifies a host directly or is an MX name; it cannot be a CNAME. ---------------------------------------------------------------------- > => it rewrites it because it checkes it and gets the canonical name as > a side effect, not because aliases are not legal... As explained above, they were illegal in MAIL and RCPT commands of => but they are not more illegal. BTW the Sender-SMTP is likely a MTA. Today the canonization is considered only as useful (if it is not performed, the next MTA will have to resolve the alias again) but no more as mandatory or necessary. SMTP, at least. Of course, you could argue that bodies (From: and To:) may be different from envelopes (MAIL and RCPT), though. => I argue that your MUA should accept what you give as soon as it is valid and it knows what to do with it. The bottom line is that it is still a bad practice to use aliases in mail address domains for these reasons. => not only it is not a bad practice (the first agent on the path can resolve the alias, before RFC 2821 it was the first agent using SMTP at its sending side) but it is a very common practice. What do you believe aliases are for? Instead, we can just use A records in most cases. => I don't understand this comment about A RRs (do you suggest to use only litterals?) > Note that SMTP does not require the name exists... Grrr...:-) => IMHO MX RRs are a nice idea. With HTTP 1.1 virtual hosting they are more than necessary! Regards Francis.Dupont@enst-bretagne.fr PS: for other readers: MTA = Mail Transfer Agent, MUA = Mail User Agent. A MTA is the software which puts mails from node to node, a MUA is the software which we use to read and write mails. SMTP (Simple Mail Transfer Protocol) is the protocol used between MTAs even it may be used to submit mails (i.e., from the MUA to the first MTA).