[Pkg-exim4-users] mailname for outgoing mail

[Ross Boylan]

On Wed, 2006-06-28 at 11:09 +0200, Marc Haber wrote:
> On Tue, Jun 27, 2006 at 02:31:02PM -0700, Ross Boylan wrote:
> > On Mon, 2006-06-26 at 14:12 +0200, Marc Haber wrote:
> > > Using both "hide local mail name in outgoing mail" in conjunction with
> > > a mailname set by the user does not seem to make sense in all
> > > situations. It is, however, possible that there are situations in
> > > which this might be desireable, which is the reason why the debconf
> > > scripts are not checking for this situation.
> > Ah, I forgot that /etc/mailname is not the only source of domains in
> > mail headers.  "hide local mail name" will operate both on domains
> > from /etc/mailname (which is what was confusing me and John) and domains
> > from other sources (e.g., MUA's).
> 
> Hmmm. Any idea how to explain this better?
Without having the templates in front of me, this is hard.  It's also
hard because it's hard to think of brief ways to say this.  Perhaps
after the second question add (/etc/mailname only affects unqualified
addresses, while this setting affects all adresses).

But the bigger thing that's puzzling is that there there are two
questions that seem to be addressing the same issue, even if they differ
in detail.

Perhaps since /etc/mailname is the province of the whole system it
should be the responsibility of the Debian installer to set it up, not
the particular packages (mail, news, ....).
> 
> > Is it possible this facility, or really this question, is generating
> > more confusion than it's worth?  I guess it depends partly on how likely
> > FQDN's are to slip into the mail headers.
> 
> Yes, that's an entirely valid possibility. I cannot comment about
> that, since all my boxes have fixed IP addresses and valid hostnames
> and I have thus never needed nor used the "hide local mail name"
> option. Since I didn't write this particular part of the config, and
> we stayed pretty close to what exim 3 did, I can't judge whether this
> option makes any sense.
> 
> Andreas, can you say something about this?
> 
> > > > Basically the same ambiguity occurs if I consult my current testing
> > > > man page for mailname:
> > > > 
> > > >   The file /etc/mailname is a plain ASCII configuration file, which on a
> > > >   Debian system contains the visible mail name of the system.  It is
> > > >   used by many different programs, usually programs that wish to send or
> > > >   relay mail, and need to know the name of the system.
> > > > 
> > > >   The file contains only one line describing the fully qualified
> > > >   domain name that the program wishing to get the mail name should use
> > > >   (that is, everything after the @).
> > > > 
> > > > I want the visible name to be "betterworld.us", but the FQDN of the
> > > > system is "corn.betterworld.us."
> > > 
> > > So you want "betterworld.us" in there, I think. What happens when you
> > > do this?
> > It works.  It had a slightly odd effect for me of sending all my mail to
> > a remote system.
> 
> Very interesting. Can you explain exactly what happened? Did you have
> betterworld.us in local_domains at this time?
No.  Did I leave anything else out of the explanation below?
> 
> > Here was the situation: I had an existing system, wheat.betterworld.us,
> > that was my main system.  I was installing a new system,
> > corn.betterworld.us, that will someday take over as primary.  Mail to
> > x at betterworld.us gets routed to wheat from corn.  When I put
> > betterworld.us as my /etc/mailname on corn, my mail from corn ended up
> > going to wheat.  That's really fine for the interim, and once corn
> > becomes  primary it will get the mail going to x at betterworld.us.
> > (Actually, I added some routers since to fiddle with this).
> > 
> > I go into this odd setup just to clarify what the effect of this
> > configuration was, since you asked what happened.
> 
> Actually, this setup doesn't seem odd at all to me. I don't see any
> problems, but since you had problems, things are weird and unclear to
> me.
Well, I was surprised that mail from corn ended up on wheat, but once it
happened I decided it was exactly the behavior I wanted.  I think part
of the reason it happened was that scripts that generated system mail
(e.g., logcheck) used /etc/mailname in places, and so appeared to be
sending from and to betterworld.us, not corn.betterworld.us.  I
deliberately didn't want corn picking up mail to betterworld.us, so it
passed it on appropriately.

I've subsequently modified the routers so I get a local copy (local on
corn) as well.

Another thing I left out is that the new system (corn) was basically
only getting its internal mail.  Almost all my mail continued to go to
my "production" system.

Ross