Problems sending to Master400.it

 In your previous mail you wrote:

   Hi,

   my PP mail MTA just received a message via x.400 originating in the x.400
   ADMD Master400 in Italy.  The sending user had requested a positive
   delivery report for the message.  Unfortunately, my PP MTA was not
   configured to route the DR back via x.400, so it tried to use SMTP instead.
   Your system, corton.inria.fr is the preferred mail exchanger for the
   Master400.it domain and its subdomains.

   Sending back the DR via SMTP is not really a problem for my system
   (although it leads to loss of functionality of the sender of the original
   message), but unfortunately this failed.  After looking into this a little
   further, it appears that it is corton.inria.fr which is the problem. My PP
   MTA said:

   > Your message was not delivered to  
   >         VINCENZO.COZZOLINO at ENEL.ENELUTI.Master400.it
   >         for the following reason:
   >         Unknown Address
   >         MTA 'ENEL.ENELUTI.Master400.it' gives error message 
   >         <VINCENZO.COZZOLINO at ENEL.ENELUTI.Master400.it>... hostname <
   >         ENEL . ENELUTI . Master400 . it > unknown to name-server 

   This was verified this way:

   % mconnect corton.inria.fr
   connecting to host corton.inria.fr (192.93.2.5), port 25
   connection open
   220 corton.inria.fr The EUnet gateway to France - Thu, 2 Jul 1992 13:44:06 +
  0200 - (Sendmail+IDA+ 5.65c8d/92.02.29)
   vrfy vincenzo.cozzolino at enel.eneluti.master400.it
   554 vincenzo.cozzolino at enel.eneluti.master400.it... hostname < enel . enelut
  i . master400 . it > unknown to name-server
   quit
   221 corton.inria.fr closing connection
   %

   Which name-server is corton talking about?  The master400.it domain has (as
   far as I can see) been properly registered in the DNS with both a "direct"
   MX and a wildcard MX for *.master400.it.

   The parties wanting to communicate would probably appreciate it if this
   problem could be fixed.  If you could report back to me, I will notify the
   two parties wanting to communicate.


   Thanks.

   - Havard, (one of) postmaster at runit.sintef.no

--> Havard,

I (one of the manager of the EUnet-FR backbone machine: corton.inria.fr)
would have been deeply flattered by Master400.it selecting us as their
relay between SMTP and X.400 world (likely based on the excellence
of our service). This choice would of course have led to some kind of
'contract', or at least minimum initial agreement; which we often
accept in the context of EUnet to help connectivity.

Unfortunatly, no such agreement exist, nor any initial agreement have
ever been made between Master400 and EUnet-FR; agreement which would
have allowed us to set up the proper dedicated routes directing to Master400 
once the mail is caught by the MX on corton.

You will certainly understand that it's quite hard for us to set up
a special route (eg: non MX driven) for an entity we have never known
of before.

I suspect that this MX has been set by persons not understanding the
full details and subtleties of MX, a well used tehcnique in the 
IP world. May I suggest those people read the excellent paper 
Piet Beertema once wrote in the context of RIPE DNS WG, as stored
in ~ftp/ripe/doc/lpr/DNS-advice.txt on machine mcsun.eu.net
Please note that this paper has been approved as a RIPE recommendation.
It contains a good description of this "MX records surprise"
(quoting Piet's paper):

   In a sense similar to point 3. Sometimes nameserver managers enter MX
   records in their zone files that point to external hosts, without first
   asking or even informing the systems managers of those external hosts.
   This has to be fought out between the nameserver manager and the systems
   managers involved. Only as a last resort, if really nothing helps to get
   the offending records removed, can the systems manager turn to the naming
   authority of the domain above the offending domain to get the problem
   sorted out.

Here is what DNS query yield on corton:

> Master400.it
Server:  corton.inria.fr
Address:  192.93.2.5

Master400.it    preference = 10, mail exchanger = corton.inria.fr
Master400.it    preference = 20, mail exchanger = infngw.infn.it
Master400.it    preference = 30, mail exchanger = cosine-gw.infn.it
corton.inria.fr internet address = 192.93.2.5
infngw.infn.it  internet address = 131.154.1.1
cosine-gw.infn.it       internet address = 140.105.6.99

Another query for zone trasnfert for IT, as stored on NIS.GARR.IT
shows the following setting up: 

master400                      MX    10   corton.inria.fr
 master400                      MX    20   infngw.infn.it
 master400                      MX    30   cosine-gw.infn.it
 *.master400                    MX    10   corton.inria.fr
 *.master400                    MX    20   infngw.infn.it
 *.master400                    MX    30   cosine-gw.infn.it

And also:
 y-net                          MX    10   corton.inria.fr
 y-net                          MX    20   infngw.infn.it
 y-net                          MX    30   cosine-gw.infn.it
 *.y-net                        MX    10   corton.inria.fr
 *.y-net                        MX    20   infngw.infn.it
 *.y-net                        MX    30   cosine-gw.infn.it
The latter one direct mail for *y-net.it to the gateway  to
ynet-gw, which happens to be chenas.inria.fr rather than
corton.inria.fr
The recommendation by YMU (Ynet management unit) are that
an MX should point to chenas.inria.fr, and only to it.
This later point has to be dealt with directly with Teleo
in Bruxelles.


 Cordialement,
 Yves


 ----------------------------------------------------------------
 Yves Devillers
 Internet:    Yves.Devillers at inria.fr  Institut National de Recherche
 Goodie-Oldie: ...!uunet!inria!devill  en Informatique et Automatique
 Phone: +33 1 39 63 55 96              INRIA, Centre de Rocquencourt
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