Bug#304838: Re: Bug#304838: exim4-config: "mail sent by smarthost; no local mail" causes weird behavior wrt local delivery

[Marc Haber]

Hi,

On Mon, May 23, 2005 at 04:40:58PM -0700, Andrew Pimlott wrote:
> [I was left out of the loop on replies to this bug that I filed.]

Sorry, I just realized that when you complained. I have changed my bug
processing script appropriately.

> Marc Haber <mh+debian-packages@zugschlus.de> wrote:
> > On Fri, Apr 15, 2005 at 09:14:35PM -0700, Andrew Pimlott wrote:
> > > I have just installed a Debian unstable machine and configured exim4 for
> > > "mail sent by smarthost; no local mail".  This has two weird effects
> > > (which I don't think are the same as bug 297841):  (Throughout this
> > > message, I have replaced my domain with example.com.)
> > > 
> > > 1.  Mail to real-andrew is not delivered locally; instead, exim tries to
> > >     deliver to real-andrew@example.com.
> > 
> > This is unreproducible here, it delivers fine to the smarthost:
> 
> Maybe you misunderstood my example.  I ran "mail real-andrew", with no
> "@domain", and it tried to deliver to real-andrew@example.com.  But the
> whole puprose (I thought) of real- addresses is that they will always be
> delivered locally, not sent to a smarthost or anywhere else.  This is
> what the debconf question exim4/dc_postmaster says:
> 
>     Note that postmaster's mail should be read on the system to which it
>     is directed, rather than being forwarded elsewhere, so (at least one
>     of) the users you choose should not redirect their mail off this
>     machine. Use a "real-" prefix to force local delivery.

I understand that might be confusing, but frankly, I do not see how
this could be reworded without diving into pseudocode like ("if you
chose..."). Maybe we should display a different template for the
satellite setup, but that would greatly complicate the debconf code,
and it is pretty hard to understand anyway.

> > No. "no local mail" does really mean, "no local mail", and the
> > templates cannot be changed before sarge release.
> 
> First, this puts the user in a difficult spot, because the debconf
> templates contain contradictory statements.  I realize that changing
> templates has a high cost, but I would consider it worthwhile because
> the current wording is so confusing.

Not before sarge release, sorry.

We are in a bad situation here since we froze the Debconf templates
over year ago, well before the base freeze which nobody thought of
taking so much time. Changing them before sarge release is totally out
of the question.

> Second, please consider supporting real- addresses in all
> configurations.  Since people have to ask for local delivery explicitly,
> it seems unlikely that it would cause problems.

The prefix "real-" can be set from outside, and "no local mail" is
crystal clear. This setup is meant for cluster nodes or pool machines,
where local delivery would be _very_ confusing.

If you want to have no local mail, choose a different option.

> Moreover, I think many
> users would like a "no local mail except for system messages" option,
> and this change would provide it.

I don't think that this is a very common configuration.

> If you will not make this change, I
> would at least clarify in Debconf that "no local mail" means "even
> system messages".

Not before sarge. After sarge, the debconf templates will suffer some
re-work anyway, and I'll ponder clarifying your issue then.

> And what will you recommend that users enter for
> dc_postmaster?

Probably, the recommendation will be empty, delivering postmaster mail
as any other message to the smarthost. I'm currently pondering to
ditch the question entirely for satellite setups, but it might be a
good idea to have a possibility to encode the host name or host group
information in the postmaster target.

Greetings
Marc

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