Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site plus5.UUCP Path: utzoo!watmath!clyde!burl!ulysses!mhuxr!mhuxt!houxm!ihnp4!mgnetp!we53!busch!wucs!wuphys!plus5!hokey From: hokey@plus5.UUCP (Hokey) Newsgroups: net.mail.headers Subject: Re: From: and To: in UUCP land Message-ID: <838@plus5.UUCP> Date: Sat, 17-Aug-85 00:15:34 EDT Article-I.D.: plus5.838 Posted: Sat Aug 17 00:15:34 1985 Date-Received: Tue, 20-Aug-85 05:44:55 EDT References: <835@plus5.UUCP> <742@vortex.UUCP> Reply-To: hokey@plus5.UUCP (Hokey) Organization: Plus Five Computer Services, St. Louis, MO Lines: 45 Lauren, I basically agree with you in your point (1) about using @ in the transport layer if you "know" how the recipient will handle it. My only concern is that while it may be OK to send a site an "rmail user@site", I would not want to send that site a hybrid recipient. >2) @'s in the To: and From: lines are the ONLY way to maintain > 822 compatibility with the outside world, and many smaller > machines with limited software are starting to act as gateways > and can't be expected to do @/! conversion. I agree with you here, too. The format of mail in 822 land *outside* of UUCP land should be in @ format. *Inside* uucp land it should be in ! format. Notice that the futzing is done at the gateways, another point where we agree. My answer to your point about small machines is to treat them as being *outside* UUCP land if the machines of which you speak use strict 822 mailers, and treat them as *inside* UUCP land if they only handle ! format. This means that mail sent to these machines would have the header put (left) in the correct format by the appropriate gateway (relay) site. If From: and To: lines are left in @ format, dumb mailers will produce hybrid routes which will not always parse correctly when the mail gets to a site which can recognize ! and @. I like to avoid problems by making sure they cannot happen. While we are on the point about >From vs. From: replies, many mailers will still source-route a From: reply (i.e.: given "From: a!b To: c!d", a From: reply at c will send mail to a!b and a!c!d. Very dull.). A related point which I did not mention, recipients should be specified in their shortest form; if somebody sends mail to ihnp4!wucs!plus5!hokey, the To: line should only say plus5!hokey. (Yes, I know this is a bad example because plus5 is not syntactically rooted.) There are nasty ramifications of multiple recipients while the mail heads off via multiple sites. I suspect the solution to this is to always use "short" recipients and put enough smarts into the mailers to pass stuff along to smarter neighbors. Always giving ! precedence over @ in a >From line can produce an erroneous parse. I think rpw once showed a very good hypothetical example of this case, and I believe Peter Honeyman has done likewise. -- Hokey ..ihnp4!plus5!hokey 314-725-9492