Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!mnetor!seismo!columbia!rutgers!ames!ptsfa!vixie!paul From: paul@vixie.UUCP (Paul Vixie Esq) Newsgroups: comp.mail.misc,comp.mail.uucp Subject: Re: whether to prefix myhost! onto the From: or not.. Message-ID: <600@vixie.UUCP> Date: Mon, 20-Apr-87 20:20:38 EST Article-I.D.: vixie.600 Posted: Mon Apr 20 20:20:38 1987 Date-Received: Tue, 21-Apr-87 23:59:10 EST References: <16238@amdcad.AMD.COM> Reply-To: paul@vixie.UUCP (Paul Vixie Esq) Organization: Vixie Enterprises, San Francisco Lines: 159 Summary: modify the From_, but never the From: Xref: mnetor comp.mail.misc:203 comp.mail.uucp:484 The various standards in place around the net (in RFC form) say: no. In article <16238@amdcad.AMD.COM> bandy@amdcad.UUCP (Andy Beals) writes: # Now that we have bsmtp, the answer is simple. If you want to be # domainist, send mail to all your remote neighbours with bsmtp and # don't prefix myhost! on to the front of the From: header. You don't get a lot of choice whether to be a domainist--the world at large is becoming domainist. If you don't want to use domains, or routing, etc., use the From_ line for your replies -- this is banged up by UUCP, and is (usually) left along by sendmail. Leave the From: line alone in all cases, however! Here's an example (Sun, are you listening?): I am vixie!paul. vixie talks to ptsfa, who talks to sun and ames. Sun tweaks From: lines -- ames doesn't. Ptsfa doesn't. When sun!foo!bar sends me mail through sun!ptsfa!vixie!paul, the message gets here looking like From ptsfa!sun!foo!bar From: sun!foo!bar If ames!foo!bar sends mail to sun!ptsfa!vixie!paul, it looks like: From ptsfa!ames!foo!bar From: foo!bar Now, my autorouter will handle either -- but sun may not be the fastest way to foo, I'd rather find a route directly to foo than directly to sun. (This can be fixed by doing aggressive path optimization, but that has problems of it's own). The From_ line is correct for literal routers, and the From: line should be kept pristine for autorouters. Granted, many literal routers (v6mail, etc) depend on a full route in the From: line, but it's easier to fix them to use From_ than it is to add another header for RFC-standard mailers to use.) # Be sure # that you know how to route though! (Otherwise mail won't get though # when people reply back) The people who have to know how to autoroute are the people trying to reply! If you would leave the From: line alone, they wouldn't count on it being possibly correct (it is, sometimes). If they saw From foo!bar!baz!xyzzy!fump!joebloe From: fump!joeblow ... they would know very quickly whether their machine talked to 'fump', and they would know which From? line to use. If they saw instead From foo!bar!baz!xyzzy!fump!joebloe From: foo!baz!fump!jowblow They could infer (correctly, in this case) that the longer path is correct. But there are more bizarre possibilities than this, as every e-mail user knows. (Sorry, lame example, but I think the point is made). # If you want your mail to work rather than be strictly correct according # to the rules, ... and to break more mailers in the evolving RFC world, and keep this incompatible nonsense around another few years ... # prefix myhost! on the front of mail to your remote neighbours # and send it via rmail. I use smail here. I wish ATT and UCB would put it into their standard distributions, and support it. It's PD, and easily available, but many sites don't run it just because they would have to support it themselves. The UUCP project may solve this problem by providing support of their own, but many small and conservative sites would prefer a single vendor solution... # Mail will go through because it's worked this # way for years. Mail *may* go through because of all the people between you and your mailee who are running broken and non-standard software. It may also come back as undeliverable. It will probably go into some postmaster's mailbox, after which it will go to the bit bucket. # (Not to mention that you should probably convert @hosts into # leading host.do.main!s just so someone else's mail down the road won't break # it up in an un-replyto-able way...) NO NO NO! Sun does this too -- rewriting addresses is WRONG! Sun gets addresses in the form paul@vixie from ptsfa, and rewrites them into sun!vixie!paul. Sun doesn't talk to vixie. Is this the kind of replyability you want? Use the From_ line, please (pleading voice)... # Now, to all the hosts (leadsv, for example) that pass mail without adding # myhost! to the front but don't pass mail via bsmtp, tisk tisk I applaude them! Yay team! Go go go! Yip! They are conforming to the standard -- which applies to you no matter what transport protocol you use to move mail. # -- do you know # how much mail you cause to bounce every day? Like the little-endian/big-endian battles (I'm LE, btw), either side's method would work well if the other side would conform. Unlike LE/BE, there is a standard (lots of standards, really) for mail addresses -- it says several apparently unpopular things: -- don't alter addresses in the headers, only in the envelope -- ignore ! when @ is present ("@" > "!" > "%") I get mail bounced too. If everyone would conform to the published standards, it wouldn't happen (so often :-)... John Gilmore responds to Andy's article: # [mentions breaking of hoptoad!leadsv connection, explaining that...] # All they would have had to do is add "leadsv!" to the front of what they # had, and/or avoid using a domain name until it was registered; this was too **************************************************** # much for them. I certainly support this. I use vixie.UUCP and it causes me all kinds of trouble. I'm going to change it to just read 'vixie' until i get my domain named. Leadsv should do the same. # I don't think there's a need for UUCP Protocol Police, but if you have # a neighbor that generates screwy addresses, producing lots of bounced # mail, consider applying a bit of peer pressure. As their links drop away # they might schedule time for mailer maintenance. Whether or not they do, # your site will never be bothered by their junkmail again! # -- # Copyright 1987 John Gilmore; you can redistribute only if your recipients can. # (This is an effort to bend Stargate to work with Usenet, not against it.) # {sun,ptsfa,lll-crg,ihnp4,ucbvax}!hoptoad!gnu gnu@ingres.berkeley.edu (John, for the record: do you want your copyright notice included in followups? It's makes things messy...) I agree with this, though I'd implement it differently. If they cause lots of bounced mail, forward the mail to them and do not handle it yourself. The people who sent (and did not receive) the mail will do your job for you in the form of endless nastygrams. You can offer to send them a copy of smail. You CAN be constructive at a small cost to yourself -- think of the help you give to the net, if not to the offender (or yourself!). ---- Andy, I'm not as nasty as this article indicates. I stepped up the voltage a little bit to show that there are hot feelings on BOTH SIDES. Your solution would put the Internet back several years, progress-wise. UUCP is (becoming) part of the Internet, to the great benefit of both. If everyone gets behind the published standards and pushes, gently but firmly, the end result will be a single, world-wide, homogeneous network where mail is fairly reliable and you don't have to memorize the network topography to get things from A to B. Please, people: in your comments on this issue, Be Constructive. -- Paul A. Vixie {ptsfa, crash, winfree}!vixie!paul 329 Noe Street dual!ptsfa!vixie!paul@ucbvax.Berkeley.EDU San Francisco CA 94116 paul@vixie.UUCP (415) 864-7013