Return to BSD News archive
#! rnews 2544 bsd Path: euryale.cc.adfa.oz.au!newshost.carno.net.au!harbinger.cc.monash.edu.au!news.mira.net.au!vic.news.telstra.net!news.telstra.net!psgrain!iafrica.com!uct.uni.net.za!ru.uni.net.za!wits.uni.net.za!howland.erols.net!news.bbnplanet.com!cam-news-hub1.bbnplanet.com!uunet!in2.uu.net!128.248.178.247!koobera.math.uic.edu!djb From: djb@koobera.math.uic.edu (D. J. Bernstein) Message-ID: <1996Dec1821.08.45.5092@koobera.math.uic.edu> Date: 18 Dec 1996 21:08:45 GMT Newsgroups: comp.mail.sendmail,comp.mail.smail,comp.unix.bsd.freebsd.misc Subject: Re: Sendmail vs. Smail... References: <57tf61$gq7@raven.eva.net> <1996Dec16.152941.1706@isac.hces.com> <1996Dec1721.54.58.11342@koobera.math.uic.edu> <598tvm$t0h@ezekiel.eunet.ie> Organization: IR Lines: 41 Xref: euryale.cc.adfa.oz.au comp.mail.sendmail:35334 comp.mail.smail:2736 comp.unix.bsd.freebsd.misc:32767 In article <598tvm$t0h@ezekiel.eunet.ie>, Nick Hilliard <nick@eunet.ie> wrote: > This is not always the case. I didn't say ``always.'' I said ``most common reason.'' I also said ``there are many more contributing factors.'' > If the remote host has DNS checking of RCPT's > enabled, then this can (and generally will) clock up considerably more > latency than TCP round-trips. RTTs are a more serious problem than DNS lookups, both on average and in the worst case. (RTTs are also more difficult to fix.) > you're really getting hung up on this particular Taiwan example. It's an extreme example, certainly, but it's also a major disaster for the recipients. A user doesn't care that you've successfully delivered a billion messages; you've failed to deliver _his_ mail, and that's what's important. > b) (observation) Route flap is not the major cause of delayed mail. Of course not. What does that have to do with anything? We're not talking about mail in general; we're talking about a special class of messages, namely those where multiple RCPTs can be used. [ same point repeated several times ] You're really getting hung up on the fact that most mail gets through. Nobody's disputing this. I'm simply pointing out some of the reasons that _on occasion_ multiple RCPTs are a disaster. > Also, why did qmail originally do separate delivery of the same message to > multiple sites? Huh? Anything else would drastically slow down mailing lists. In qmail, every delivery happens immediately, subject to the concurrency limit set by the sysadmin. This is the obvious way for an MTA to work. ---Dan Put an end to unauthorized mail relaying. http://pobox.com/~djb/qmail.html