hostname:/# apt-get --simulate install postfix
Reading Package Lists... Done
Building Dependency Tree... Done
Suggested packages:
  postfix-mysql postfix-pgsql postfix-ldap postfix-pcre
Recommended packages:
  resolvconf
The following packages will be REMOVED:
  exim4-base exim4-config exim4-daemon-heavy
The following NEW packages will be installed:
  postfix
0 upgraded, 1 newly installed, 3 to remove and 6 not upgraded.
Remv exim4-daemon-heavy (4.50-8sarge2 Debian:3.1r6/oldstable) [mutt at mailx subversion-tools ]
Remv exim4-base (4.50-8sarge2 Debian:3.1r6/oldstable) [mutt at mailx subversion-tools ]
Remv exim4-config (4.50-8sarge2 Debian:3.1r6/oldstable) [mutt at mailx subversion-tools ]
Inst postfix (2.1.5-9 Debian:3.1r6/oldstable)
Conf postfix (2.1.5-9 Debian:3.1r6/oldstable)