Exim4 as a smarthost : Unrouteable address

[rudu <rudu@cegetel.net>]

Hi all,

Until recently my machines running debian testing used to send me 
e-mails as reports from cron tasks or from LAMP applications.
This is not working anymore.
I did of course a dpkg-reconfigure exim4-config to get this 
/etc/exim4/update-exim4.conf.conf file :
[...]
# This is a Debian specific file

dc_eximconfig_configtype='satellite'
dc_other_hostnames='*'
dc_local_interfaces='127.0.0.1;192.168.0.20'
dc_readhost='example.org'
dc_relay_domains='*'
dc_minimaldns='false'
dc_relay_nets='192.168.0.0/24'
dc_smarthost='mail.myprovider.fr::465'
CFILEMODE='644'
dc_use_split_config='false'
dc_hide_mailname='true'
dc_mailname_in_oh='true'
dc_localdelivery='mail_spool'

But here is an attempt to actually send a mail :

~$ echo 'Hello there !!' | mail my.name@domain.org -s Test13 -v
LOG: MAIN
  <= jean@example.org U=jean P=local S=453
jean@poste1:~$ delivering 1hvLI6-0001yn-GI
R: system_aliases for my.name@domain.org
LOG: MAIN
  ** my.name@domain.org: Unrouteable address
LOG: MAIN
  <= <> R=1hvLI6-0001yn-GI U=Debian-exim P=local S=1668
delivering 1hvLI6-0001yp-Kr
R: system_aliases for jean@example.org
R: hub_user for jean@example.org
R: system_aliases for jean@example.org
R: hub_user_smarthost for jean@example.org
T: remote_smtp_smarthost for jean@example.org
LOG: MAIN
  Completed
LOG: retry_defer MAIN
  == jean@example.org R=hub_user_smarthost T=remote_smtp_smarthost 
defer (-53): retry time not reached for any host for 'example.org'

I keep getting this "Unrouteable address" whatever address I try to 
write to, addresses who do receive mails via thunderbird.
Thunderbird is also successfully using the smtp server credentials I 
feed exim4 with ...

I must be missing something obvious here but I'm completely in the dark.

Thanks for any help,
Rudu