Xref: utzoo comp.mail.misc:3082 comp.mail.sendmail:1449 Path: utzoo!attcan!uunet!lll-winken!brutus.cs.uiuc.edu!usc!snorkelwacker!bloom-beacon!eru!luth!sunic!mcsun!ukc!newcastle.ac.uk!turing!ncrr From: C.R.Ritson@newcastle.ac.uk (Chris Ritson) Newsgroups: comp.mail.misc,comp.mail.sendmail Subject: Re: Bouncing mail for expired users Summary: How not to set off a mail loop Message-ID: <1990Mar15.112945.5329@newcastle.ac.uk> Date: 15 Mar 90 11:29:45 GMT References: <5637@ur-cc.UUCP> <25F514B1.5E18@tct.uucp> <25F83AB4.290E@tct.uucp> Sender: C.R.Ritson@newcastle.ac.uk Organization: Computing Laboratory, U of Newcastle upon Tyne, UK NE17RU Lines: 33 In article <25F83AB4.290E@tct.uucp> chip@tct.uucp (Chip Salzenberg) writes: >According to watson@shinobu.sgi.com (David M. Watson, Jr.): >>This and the other automatic response schemes create a distressing >>possibility. In this particular case, the pathological situation arises >>when a user who has just sent mail to an expired user becomes expired >>herself. (A mail loop is described), and the writer suggests detecting cirtain common Unix keywords to break this loop. Surely the right thing to do is to ensure that when YOU bounce mail, YOU fill in the headers in the message going out, so that if this message is bounced by a less intelligent mailer, then it ends up (depending on your preferences) in the waste bin, or with the postmaster. The important thing is that it must NOT bounce if it does come back to you. I beleive this is described in RFC822, but do not have a copy to hand now. Please don't go down the same route that seems to have been taken by many implementations of the "listserv" software. It is broken, and is the cause of many mail loops. Chris Ritson. -- ARPA : C.R.Ritson@newcastle.ac.uk JANET: C.R.Ritson@uk.ac.newcastle UUCP : ...!ukc!newcastle.ac.uk!C.R.Ritson PHONE: +44 91 222 8175 FAX : +44 91 222 8232 TELEX: uk+53654-UNINEW_G SNAIL: Computing Laboratory, University of Newcastle upon Tyne, UK, NE1 7RU ARPA : C.R.Ritson@newcastle.ac.uk JANET: C.R.Ritson@uk.ac.newcastle UUCP : ...!ukc!newcastle.ac.uk!C.R.Ritson PHONE: +44 91 222 8175 FAX : +44 91 222 8232 TELEX: uk+53654-UNINEW_G SNAIL: Computing Laboratory, University of Newcastle upon Tyne, UK, NE1 7RU