apt-get install error

apt-get install mc
Reading package lists... Done
Building dependency tree
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 exim4-base : Depends: exim4-config (>= 4.30) but it is not going to be installed or
                       exim4-config-2
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

ls -l /etc/apt/sources.list
-rw-r--r-- 1 root root 609 Nov 28  2011 /etc/apt/sources.list

# apt-get -f install mc
Reading package lists... Done
Building dependency tree       
Reading state information... Done
You might want to run 'apt-get -f install' to correct these:
The following packages have unmet dependencies:
 exim4-base : Depends: exim4-config (>= 4.30) but it is not going to be installed or
                       exim4-config-2
E: Unmet dependencies. Try 'apt-get -f install' with no packages (or specify a solution).

apt-get -f install

cat  /etc/apt/sources.list

cat  /etc/apt/sources.list
#
# deb cdrom:[Debian GNU/Linux 6.0.3 _Squeeze_ - Official i386 NETINST Binary-1 20111008-19:55]/ squeeze main
#deb cdrom:[Debian GNU/Linux 6.0.3 _Squeeze_ - Official i386 NETINST Binary-1 20111008-19:55]/ squeeze main
deb http://ftp.de.debian.org/debian/ squeeze main
deb-src http://ftp.de.debian.org/debian/ squeeze main
deb http://security.debian.org/ squeeze/updates main
deb-src http://security.debian.org/ squeeze/updates main
# squeeze-updates, previously known as 'volatile'
deb http://ftp.de.debian.org/debian/ squeeze-updates main
deb-src http://ftp.de.debian.org/debian/ squeeze-updates main

apt-get -f install

apt-get update && apt-get install mc