Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ucla-cs.ARPA Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!mtuxo!mtunh!mtung!mtunf!ariel!vax135!cornell!uw-beaver!tektronix!hplabs!sdcrdcf!trwrb!trwrba!cepu!ucla-cs!wales From: wales@ucla-cs.UUCP Newsgroups: net.mail,net.mail.headers Subject: Re: Handling %'s and forwarding mail Message-ID: <6286@ucla-cs.ARPA> Date: Tue, 9-Jul-85 18:42:18 EDT Article-I.D.: ucla-cs.6286 Posted: Tue Jul 9 18:42:18 1985 Date-Received: Sat, 13-Jul-85 12:58:40 EDT References: <226@harvard.ARPA> Reply-To: wales@ucla-cs.UUCP (Rich Wales) Distribution: net Organization: UCLA Computer Science Department Lines: 35 Xref: watmath net.mail:915 net.mail.headers:497 Kevin Crowstonasked what to do with an address such as the following: xyz%cshost.csnet@csnet-relay.arpa The correct thing to do is his proposed answer #1. Namely, open an SMTP connection to CSNET-RELAY.ARPA and, at the appropriate point, say: RCPT TO: CSNET-RELAY.ARPA then has the responsibility to worry about interpreting the address and forwarding the mail to the "cshost.csnet" machine. The person who replied to Kevin's article by saying that the sending host should transform the address into is mistaken. The sender should not make any effort whatsoever to break down or inter- pret the "local part" of an address (i.e., the part to the left of the at-sign); that is exclusively the province of the destination host. To quote from RFC822, Section 6.2 (page 27): The domain-dependent string [i.e., the "local part" of the address] is uninterpreted, except by the final sub- domain; the rest of the mail service merely transmits it as a literal string. While it is the case that CSNET-RELAY.ARPA happens to use "%" to denote a "subnetting" operation (as do several other hosts), this convention is NOT part of the official addressing standard and should NOT be hard- wired into an outgoing mail handler. -- Rich Wales // UCLA Computer Science Department // +1 213-825-5683 3531 Boelter Hall // Los Angeles, California 90024 // USA ARPA: wales@UCLA-LOCUS.ARPA -or- wales@LOCUS.UCLA.EDU UUCP: ...!(ihnp4,ucbvax)!ucla-cs!wales