From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: From: David Presotto To: 9fans@cse.psu.edu Subject: Re: [9fans] rewriting From: In-Reply-To: <1049385309.1074.58.camel@perro> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="upas-agihxgqkoqjnkccfhzldkdbcxx" Date: Thu, 3 Apr 2003 12:07:39 -0500 Topicbox-Message-UUID: 8973cd70-eacb-11e9-9e20-41e7f4b1d025 This is a multi-part message in MIME format. --upas-agihxgqkoqjnkccfhzldkdbcxx Content-Disposition: inline Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Thanks. It was the rfc2476 reference was what I was having a hard time finding. --upas-agihxgqkoqjnkccfhzldkdbcxx Content-Type: message/rfc822 Content-Disposition: inline Received: from plan9.cs.bell-labs.com ([135.104.9.2]) by plan9; Thu Apr 3 11:58:16 EST 2003 Received: from mail.cse.psu.edu ([130.203.4.6]) by plan9; Thu Apr 3 11:58:14 EST 2003 Received: from psuvax1.cse.psu.edu (psuvax1.cse.psu.edu [130.203.30.6]) by mail.cse.psu.edu (CSE Mail Server) with ESMTP id EFF7519B44; Thu, 3 Apr 2003 11:58:05 -0500 (EST) Delivered-To: 9fans@cse.psu.edu Received: from ipsoluciones.com (unknown [213.0.106.67]) by mail.cse.psu.edu (CSE Mail Server) with SMTP id 9AD0F199BE for <9fans@cse.psu.edu>; Thu, 3 Apr 2003 11:56:16 -0500 (EST) Received: (qmail 6595 invoked from network); 3 Apr 2003 16:56:11 -0000 Received: from host-11.ipsoluciones.com (HELO ?192.168.1.11?) (gabidiaz@192.168.1.11) by 213.0.106.70 with SMTP; 3 Apr 2003 16:56:11 -0000 Subject: Re: [9fans] rewriting From: From: Gabriel Diaz Lopez de la Llave To: 9fans@cse.psu.edu In-Reply-To: <955b04dd781fc8ef726c1f33aef706db@plan9.bell-labs.com> References: <955b04dd781fc8ef726c1f33aef706db@plan9.bell-labs.com> Content-Type: text/plain Content-Transfer-Encoding: 7bit X-Mailer: Ximian Evolution 1.0.8 (1.0.8-10) Message-Id: <1049385309.1074.58.camel@perro> Mime-Version: 1.0 Sender: 9fans-admin@cse.psu.edu Errors-To: 9fans-admin@cse.psu.edu X-BeenThere: 9fans@cse.psu.edu X-Mailman-Version: 2.0.11 Precedence: bulk Reply-To: 9fans@cse.psu.edu List-Id: Fans of the OS Plan 9 from Bell Labs <9fans.cse.psu.edu> List-Archive: Date: 03 Apr 2003 17:55:09 +0200 Hello, I hope the following lines have some utility: RFC-821 says that CNAME is supposed to be rewritten but RFC-1123 says: 5.2.2 Canonicalization: RFC-821 Section 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. I take a look to rfc 2476 "message submission" and says " 8.7. Resolve Aliases The MSA MAY resolve aliases (CNAME records) for domain names, in the envelope and optionally in address fields of the header, subject to local policy. NOTE: Unconditionally resolving aliases could be harmful. For example, if www.example.net and ftp.example.net are both aliases for mail.example.net, rewriting them could lose useful information. 8.8. Header Rewriting The MSA MAY rewrite local parts and/or domains, in the envelope and optionally in address fields of the header, according to local policy. For example, a site may prefer to rewrite 'JRU' as ' J.Random.User' in order to hide logon names, and/or to rewrite ' squeeky.sales.example.net' as 'zyx.example.net' to hide machine names and make it easier to move users. However, only addresses, local-parts, or domains which match specific local MSA configuration settings should be altered. It would be very dangerous for the MSA to apply data-independent rewriting rules, such as always deleting the first element of a domain name. So, for example, a rule which strips the left-most element of the domain if the complete domain matches '*.foo.example.net' would be acceptable " On Thu, 2003-04-03 at 18:03, David Presotto wrote: > I've noticed over the years that if the domain name in a From: address has > a CNAME, then it gets rewritten by most sendmails. Anyone know if there > is an RFC that covers the subject? > Gabriel - --upas-agihxgqkoqjnkccfhzldkdbcxx--