Exim: frustrations configuring a satellite system

[Jean Orloff <orloff@clermont.in2p3.fr>]

Hi,

I am getting frustrated with Exim configuration for a satellite system
(call it "debsat.domain.net") whose port 25 cannot be accessed from
outside the domain. 

Inbound mail is fetched with fetchmail from "mailserv.domain.net", and
local users have an email like "user@domain.net". This requires exim
to accept SMTP, and for security, tcpd only allows SMTP connections from
localhost "127.0.0.1". Mail from outside then nicely merges with local
system mails about print errors for instance. This all works.

The problem lies with outgoing mail, especially generated by emacs
MUA's like RMAIL, VM, gnus or MH.  I configured Exim with
"mailserv.domain.net" as a smarthost, and this nearly works: valid
recipients on valid outside hosts can be reached. However, sending a
mail to a bad address, especially a non-existing host, gives NO
WARNING WHATSOEVER, leading the sender to believe the mai lwas delivered..

Of course, I added a line

   From: user@domain.net

in the header, and checked that this line was correctly present in
mails that arrived OK, so that a reply works OK. Then I wondered about
the header

    Sender: user@debsat.domain.net

that Exim insists in adding whenever the address in "From:" differs
from the local one, even if "user" is in the list of trusted users. I
even added a rewriting rule to change that to 

     Sender: user@domain.net

But all this had no effect. I then tried from netscape. Selecting
"mailserv.domain.net" as outgoing SMTP server works perfect. And
surprise: selecting "debsat.domain.net" works equally well, with or
without sender rewriting. 

So there is a difference between the way Exim sends outgoing mail
depending on whether it receives it from an SMTP session or from the
command line (presumably a different "ENVELOPE-FROM" in the connection
with the smarthost?). I'm pretty sure there must be a way to abolish
this difference, but I am tired of trying. And most of all, I cannot
believe I am the first to encounter this problem! There must be a much
simpler solution...

Any help and info most welcome!

To recap: I want my debian satellite system "debsat.domain.net" to

1) merge local administrative mail and outside incoming mail with
   fetchmail

2) have local users with same "user" names and mail names "user@domain.net"

3) be able to send outgoing mail with simple mailers like unix "mail"
   that knows nothing about SMTP, with the correct return address
   "user@domain.net" to allow simple replies and make sure any error
   message about the outgoing mail is sent to that same address
   (instead of "user@debsat.domain.net" which is not reachable)

The previous sendmail configuration script apparently did this fine,
but the new frozen one doesn't seem to.

Amities,

		Jean Orloff
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+ Tel:(33)473.40.72.27                                Fax: (33)473.26.45.98  +
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Lettre re?çue par une Compagnie d'Assurance.
   (de "Lettres allum?ées et courriers d?élirants, M. Petit, Eds. Max Valentin)

     C'est un chien dangereux, de ceux qui mangent des caniches ?à la t?él?é.
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