If you have an old PLZ, send mail

   To: plz@plz.uni-forst.gwdg.de

   Adresse:
   <Strasse> <Hausnummer>
   <W/O>-<nnnn> <Ort>
   QUIT

(no Subject line necessary)

e.g.:

Adresse:
Parkstrasse 1
W-1234 Hauptstadt
QUIT