apt-get ---> problème

["loblique" <loblique@freesurf.fr>]

Bonjour... je ne sais pas quoi faire devant un tel message d'erreur (ci-dessous) et je ne peux plus utiliser la commande apt-get. J'ai suivie pourtant le indication sur l'How-to apt :
http://www.fr.debian.org/doc/manuals/apt-howto/ch-erros.fr.html
Auriez-vous une idée pour que je m'en sorte ?
Merci par avance
loblique

debian:/etc/apt# dpkg --configure -a
dpkg: dependency problems prevent configuration of dot-forward:
 dot-forward depends on qmail (>> 1.03-woody0); however:
  Package qmail is not installed.
dpkg: error processing dot-forward (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of fastforward:
 fastforward depends on qmail (>> 1.03-woody0); however:
  Package qmail is not installed.
dpkg: error processing fastforward (--configure):
 dependency problems - leaving unconfigured
dpkg: dependency problems prevent configuration of qmail-run:
 qmail-run depends on qmail (>> 1.03-woody0); however:
  Package qmail is not installed.
dpkg: error processing qmail-run (--configure):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 dot-forward
 fastforward
 qmail-run