diff --git a/evolinux-base/tasks/default_packages.yml b/evolinux-base/tasks/default_packages.yml
index d2fee898..917ef878 100644
--- a/evolinux-base/tasks/default_packages.yml
+++ b/evolinux-base/tasks/default_packages.yml
@@ -1,9 +1,27 @@
 ---
 - name: Install/Update default packages (might take some time)
-  command: "apt-get install -yq --allow-unauthenticated {{ evolinux_default_packages | join(' ') }}"
+  apt:
+    name: "{{ item }}"
+  with_items: "{{ evolinux_default_packages }}"
+
+- name: Install/Update unauthenticated packages (might take some time)
+  command: "apt-get install -yq --allow-unauthenticated {{ evolinux_unauthenticated_packages | join(' ') }}"
   register: install_default_packages
   changed_when: not (install_default_packages.stdout | search("0 upgraded") and install_default_packages.stdout | search("0 newly installed"))
 
+
+- name: is Postfix installed?
+  shell: "dpkg -l postfix | grep '^ii '"
+  register: postfix_installed
+  failed_when: False
+  changed_when: False
+
+- name: Install lsb-invalid-mta if Postfix is not present
+  apt:
+    name: lsb-invalid-mta
+  when: postfix_installed.rc != 0
+
+
 - name: Deleting rpcbin and nfs-common
   apt:
     name: "{{ item }}"
diff --git a/evolinux-base/vars/main.yml b/evolinux-base/vars/main.yml
index 11aae658..4eec1a7a 100644
--- a/evolinux-base/vars/main.yml
+++ b/evolinux-base/vars/main.yml
@@ -1,31 +1,32 @@
 evolinux_default_packages:
-  - serveur-base
-  - strace
-  - htop
-  - iftop
-  - iptraf
-  - ncdu
-  - vim
-  - iotop
-  - rsync
-  - mtr-tiny
-  - sudo
-  - git
-  - subversion
-  - ntp
-  - screen
-  - pv
-  - apg
-  - tcpdump
-  - ntpdate
-  - lsb-release
-  - mutt
-  - pinentry-curses
-  - bc
-  - dnsutils
-  - lm-sensors
-  - conntrack
-  - hdparm
-  - lsb-invalid-mta
-  - smartmontools
-  - tree
+- strace
+- htop
+- iftop
+- iptraf
+- ncdu
+- vim
+- iotop
+- rsync
+- mtr-tiny
+- sudo
+- git
+- subversion
+- ntp
+- screen
+- pv
+- apg
+- tcpdump
+- ntpdate
+- lsb-release
+- mutt
+- pinentry-curses
+- bc
+- dnsutils
+- lm-sensors
+- conntrack
+- hdparm
+- smartmontools
+- tree
+
+evolinux_unauthenticated_packages:
+- serveur-base