Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!nrl-cmf!ukma!david
From: david@ms.uky.edu (David Herron -- One of the vertebrae)
Newsgroups: comp.mail.uucp
Subject: Re: why you should say "-d rutgers -d sun" in your pathalias command line
Message-ID: <10146@g.ms.uky.edu>
Date: 9 Aug 88 16:00:37 GMT
References: <676@bacchus.DEC.COM> <881@vsi1.UUCP> <10135@e.ms.uky.edu> <60@minya.UUCP>
Reply-To: david@ms.uky.edu (David Herron -- One of the vertebrae)
Organization: U of Kentucky, Mathematical Sciences
Lines: 60

In article <60@minya.UUCP> jc@minya.UUCP (John Chambers) writes:
>> The only excuse I've ever heard for this is that "replies along news paths
>> are always sub-optimal", never mind that you're not ever supposed to use
>> news paths for replies ...
>
>You're wrong there.  For instance, try responding by email to this article.
>You will use a news path.  Why?  Well, this machine has 4 neighbors, and 
>the news (e.g., this article) is sent to all of them.  There is therefore
>no mail path to this machine that is not a reverse news path, and if you
>respond successfully, you will have used a news path.  Q.E.D.
>

Just because you were careful and made sure that all your news neighbors
are also mail neighbors doesn't mean that will ALWAYS be the case.  One
way it will not work is if the article happens to pass through the link
between here and psuvm.bitnet.  THe Path: line will be something like:

	Path: ...!ukma!psuvm.bitnet!...!user

When it arrives here rmail will see "psuvm.bitnet!...!user" and will
attempt to route to "...!user@psuvm.bitnet".  Now, it will succeed
in doing so since we're directly connected to BITNET and have up-to-date
maps of bitnet and such.  However since the lowest common denominator
of mail on bitnet (which is all I've had the energy to support so far)
limits the local-part to 8 characters, this will fail a lot.

(and does fail a lot from the number of mail messages which bounce
into my mailbox).  (er.. 1 or 2 times a month anyway)

In general there are a number of links on the net which are not
accompanied by UUCP mail links.  One of the older examples is/was
the sites at brl.

Also you should go and check the news installation documents, rfc976,
and whatever the current rfc for the news format.  The news documents
EXPLICITLY say that you should not ever use Path: lines for replies.
And have said that for as long as I can remember (my experience with
this stuff dates back to v2.10.1 beta).


>> It seems appropriate to say somewhere in here that the only sites which
>> have the right to use user@host.uucp are the ones who appear in the maps.
>Huh?  I'll use any mail notation I can get my mailer to accept; it's my
>machine (;-).  How are you going to tell what notation I used, anyway?
>If my mailer converts the original notation to some canonical form, like
>host.uucp!user, there's no way you can reconstruct what I typed, and I'll
>have violated your rule with impunity.

I meant in their outgoing headers, silly


Oh, I know full well that "a!b@d.dom" is ambiguous ... I also know
that the mailer here generates headers which say that when it's
doing rewriting.  One of my backburner projects is to do a rewrite
of the UUCP channel in MMDF and that's one of the things I may
touch on.  Perhaps put in a routine to do a mapping to "b%a@d.dom".
-- 
<---- David Herron -- The E-Mail guy                         
<---- ska: David le casse\*'      {rutgers,uunet}!ukma!david, david@UKMA.BITNET
<----
<---- Looking forward to a particularly blatant, talkative and period bikini ...