diff --git a/install_postfix_advanced.sh b/install_postfix_advanced.sh
index 70b2517..ee45fdf 100755
--- a/install_postfix_advanced.sh
+++ b/install_postfix_advanced.sh
@@ -82,6 +82,13 @@ echo_skipped() {
 trap clean_up SIGHUP SIGINT SIGTERM
 
 
+# -------------
+# --- Some default settings
+# -------------
+
+DEFAULT_ADMIN_EMAIL="argus@oopen.de"
+
+
 # - Is this a systemd system?
 # -
 if [[ "X`which systemd`" = "X" ]]; then
@@ -102,6 +109,21 @@ if [[ -f "$conf_file" ]]; then
    source $conf_file
 fi
 
+[[ -z "$_ADMIN_EMAIL" ]] && _ADMIN_EMAIL="$DEFAULT_ADMIN_EMAIL"
+
+
+
+# -------------
+# --- Set default values for some non existent variables (i.e. no configuration file is present)
+# -------------
+
+if [[ -z "$_HOSTNAME" ]] ; then
+   _HOSTNAME="$(hostname -f)"
+   _HOSTNAME_SHORT="$(hostname)"
+   [[ "$_HOSTNAME" = "$_HOSTNAME_SHORT" ]] && _HOSTNAME=""
+fi
+
+
 clear
 echo -e "\033[21G\033[32mInstallation script for Postfix basic mailsystem \033[m"
 echo
@@ -128,6 +150,22 @@ else
    done
 fi
 
+
+
+# -------------
+# --- Some further default values depending on Hostname
+# -------------
+
+# - Set default values for ipv4- and ipv6-address
+# -
+if [[ -z $_IPV4 ]] && [[ -n "$_HOSTNAME" ]] && [[ -x "$(which dig)" ]]; then
+   _IPV4="$(dig +short "$_HOSTNAME" A)"
+fi
+if [[ -z $_IPV6 ]] && [[ -n "$_HOSTNAME" ]] && [[ -x "$(which dig)" ]]; then
+   _IPV6="$(dig +short "$_HOSTNAME" AAAA)"
+fi
+
+
 IPV4=
 echo ""
 echo -e "\033[32m--\033[m"