[ On Monday, November 22, 2004 at 10:28:39 (+0000), Philip Hazel wrote: ]
> Subject: Re: [exim] about Sender: and envelope reverse-path in today's systems
>
> On Sun, 21 Nov 2004, Greg A. Woods wrote:
> >
> > IIUC Exim, and every other unix-based mailer, can work just fine for
> > local-only purposes with unqualified user-ids as mailbox names. Maybe
> > it doesn't work that way out of the box, but don't let that stop you! ;-)
>
> Exim does not, and never has, supported unqualified local parts in
> addresses, except insomuch as it allows them on certain incoming
> interfaces, and qualifies them at the point of entry. But that is pretty
> much "syntactic sugar" on the interface. Internally, all addresses must
> be qualified. Therefore, even if using Exim for local-only purposes, a
> qualify_domain has to be defined.
Well first off, sorry for the mis-information I was spreading!
I cannot say I'm surprised at all by learning I'm wrong about this (I
should have tried reading some docs :-), nor am I surprised that this is
the way Exim behaves.
In fact for Exim's job as a full-blown MTA I would agree that the
immediate qualification of all incoming addresses upon entry is the very
best possible policy. (I've been trying to make that the default
behaviour of smail too!)
It does though explain why I've seen so many "localhost.localdomain"
kinds of domain names leak from so many different mis-configured Exim
instances (though Exim is very much a less common mailer amongst such
offending sites!).
I think this also very much underscores the argument that a full MTA
should not be used on a workstation regardless of whether or not there
are some things like daemons running on that system which might like to
use e-mail to communicate reports to the system manager.
Given all this perhaps there's a simple way to configure Exim so that it
can only accept mail via the command-line interace and so that it can
only deliver mail to a local transport? If so then the _only_ correct
host domain name to use for qualifying addresses and for message-IDs and
such in that configuration would be just plain "localhost". No dot at
the end, nothing else -- just plain "localhost". Such a configuration
would be suitable for a workstation that lived on a private network
which did not have internal DNS nor any proper SMTP gateway on its
border(s). MUAs on that workstation should be configured to fetch mail
from the local primary user's spool file as well as whatever remote POP
and/or IMAP accounts the user might use. Aliases should be set up so
that all locally delivered mail gets delivered to the primary user's
spool file. MUAs would of course also be configured to _only_ deliver
mail via SMTP or SUBMIT or similar to the ISP's outbound mail gateway.
Note I'm not suggesting this be the default configuration of Exim
(e.g. how it runs without configuration files) -- but rather that it be
the custom configuration supplied by system designers who are providing
a workstation environment.
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
