Voila ce que j'ai trouvé sur le site de la poste allemande
Prerequisites
The only precondition for use of this new service is access to the Internet. As a contracting party, you will receive from Deutsche Post Euro Express a user name and password. You use these to register and then you can go ahead and call up the services your require.
In order to register, for track & trace via telephone or if you have requests or suggestions - just call us at
01805 04 77 77 (only from within Germany)
(DM 0,24 / min or EUR 0,12 / min)
Mon. - Fri. 7 - 20 h, Sat. 8 - 14 h
or just send us an e-mail.
J'ai envoyé un mail. J'attends donc un user et password.