diff --git a/install-mailcow-ubuntu.sh b/install-mailcow-ubuntu.sh
index 5979ac2..1243d7e 100644
--- a/install-mailcow-ubuntu.sh
+++ b/install-mailcow-ubuntu.sh
@@ -1,75 +1,99 @@
 #!/bin/bash
 
-# Exit on any error
+# Exit on error
 set -e
 
+# Checkpoint file
+CHECKPOINT_FILE="/tmp/mailcow_install_progress"
+MAILCOW_DIR="/opt/mailcow-dockerized"
+
 # Function to log messages
 log_message() {
     echo "[$(date '+%Y-%m-%d %H:%M:%S')] $1"
 }
 
+# Function to save checkpoint
+save_checkpoint() {
+    echo "$1" > "$CHECKPOINT_FILE"
+    log_message "Checkpoint saved: $1"
+}
+
+# Function to get last checkpoint
+get_checkpoint() {
+    if [ -f "$CHECKPOINT_FILE" ]; then
+        cat "$CHECKPOINT_FILE"
+    else
+        echo "start"
+    fi
+}
+
+# Function to check if a step is completed
+is_step_completed() {
+    local current_checkpoint=$(get_checkpoint)
+    local step=$1
+    
+    case $current_checkpoint in
+        "docker_installed"|"fail2ban_configured"|"mailcow_installed"|"complete")
+            if [ "$step" = "system_updated" ]; then return 0; fi
+            ;;
+        "fail2ban_configured"|"mailcow_installed"|"complete")
+            if [ "$step" = "docker_installed" ]; then return 0; fi
+            ;;
+        "mailcow_installed"|"complete")
+            if [ "$step" = "fail2ban_configured" ]; then return 0; fi
+            ;;
+        "complete")
+            if [ "$step" = "mailcow_installed" ]; then return 0; fi
+            ;;
+    esac
+    return 1
+}
+
 # Check if script is run as root
 if [ "$EUID" -ne 0 ]; then 
     echo "Please run as root"
     exit 1
 fi
 
-# Update system
-log_message "Updating system packages..."
-apt-get update && apt-get upgrade -y
+# Start or resume installation
+log_message "Starting or resuming installation from checkpoint: $(get_checkpoint)"
 
-# Install essential packages
-log_message "Installing essential packages..."
-apt-get install -y \
-    ca-certificates \
-    curl \
-    gnupg \
-    ufw \
-    fail2ban \
-    git \
-    sudo
+# Step 1: Update system
+if ! is_step_completed "system_updated"; then
+    log_message "Updating system packages..."
+    apt-get update && apt-get upgrade -y
+    apt-get install -y ca-certificates curl gnupg ufw fail2ban git sudo
+    save_checkpoint "system_updated"
+fi
 
-# Install Docker
-log_message "Installing Docker..."
-install -m 0755 -d /etc/apt/keyrings
-curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
-chmod a+r /etc/apt/keyrings/docker.asc
+# Step 2: Install Docker
+if ! is_step_completed "docker_installed"; then
+    log_message "Installing Docker..."
+    install -m 0755 -d /etc/apt/keyrings
+    curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
+    chmod a+r /etc/apt/keyrings/docker.asc
 
-# Add Docker repository
-echo \
-  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
-  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
-  tee /etc/apt/sources.list.d/docker.list > /dev/null
+    echo \
+      "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
+      $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
+      tee /etc/apt/sources.list.d/docker.list > /dev/null
 
-apt-get update
-apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
+    apt-get update
+    apt-get install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
 
-# Create docker user and set up permissions
-log_message "Creating docker user and setting up permissions..."
-useradd -m -s /bin/bash dockeruser
-usermod -aG docker dockeruser
-echo "dockeruser ALL=(ALL) NOPASSWD: /usr/bin/docker, /usr/bin/docker-compose" | sudo tee /etc/sudoers.d/dockeruser
+    # Create docker user if not exists
+    if ! id "dockeruser" &>/dev/null; then
+        useradd -m -s /bin/bash dockeruser
+        usermod -aG docker dockeruser
+    fi
 
-# Configure UFW
-log_message "Configuring firewall..."
-ufw default deny incoming
-ufw default allow outgoing
-ufw allow 22/tcp
-ufw allow 25/tcp
-ufw allow 80/tcp
-ufw allow 110/tcp
-ufw allow 143/tcp
-ufw allow 443/tcp
-ufw allow 465/tcp
-ufw allow 587/tcp
-ufw allow 993/tcp
-ufw allow 995/tcp
-ufw allow 4190/tcp
-ufw --force enable
+    save_checkpoint "docker_installed"
+fi
 
-# Configure fail2ban for SSH
-log_message "Configuring fail2ban for SSH protection..."
-cat > /etc/fail2ban/jail.local << EOL
+# Step 3: Configure fail2ban
+if ! is_step_completed "fail2ban_configured"; then
+    log_message "Configuring fail2ban..."
+    cat > /etc/fail2ban/jail.local << EOL
 [DEFAULT]
 bantime = 1h
 findtime = 10m
@@ -89,129 +113,83 @@ bantime = 1d
 findtime = 10m
 EOL
 
-# Reload systemd daemon
-systemctl daemon-reload
-
-# Restart fail2ban
-systemctl restart fail2ban
-
-# Restart fail2ban
-systemctl restart fail2ban
-
-# Set up Mailcow directory and permissions
-log_message "Setting up Mailcow directory..."
-mkdir -p /opt/mailcow-dockerized
-chown dockeruser:dockeruser /opt/mailcow-dockerized
-
-# Function to get FQDN input
-get_fqdn() {
-    local fqdn
-    while true; do
-        read -p "Please enter your Fully Qualified Domain Name (FQDN) (e.g., mail.example.com): " fqdn
-        if [[ $fqdn =~ ^[a-zA-Z0-9][a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ ]]; then
-            echo "$fqdn"
-            return 0
-        else
-            echo "Invalid FQDN format. Please try again."
-        fi
-    done
-}
-
-# Get timezone
-get_timezone() {
-    local timezone
-    while true; do
-        read -p "Please enter your timezone (e.g., Europe/Berlin) [default: UTC]: " timezone
-        timezone=${timezone:-UTC}
-        if [ -f "/usr/share/zoneinfo/$timezone" ]; then
-            echo "$timezone"
-            return 0
-        else
-            echo "Invalid timezone. Please try again."
-        fi
-    done
-}
-
-# Function to configure mailcow
-configure_mailcow() {
-    local fqdn=$1
-    local timezone=$2
-    
-    # Create temporary config file
-    cat > /tmp/mailcow_config << EOL
-MAILCOW_HOSTNAME=${fqdn}
-TIMEZONE=${timezone}
-EOL
-    
-    # Ask for additional configuration
-    read -p "Do you want to customize additional mailcow configuration? (y/N): " customize
-    if [[ $customize =~ ^[Yy]$ ]]; then
-        nano /tmp/mailcow_config
-    fi
-    
-    return 0
-}
-
-# Switch to dockeruser and install Mailcow
-log_message "Installing Mailcow as dockeruser..."
-
-# Get configuration parameters
-FQDN=$(get_fqdn)
-TIMEZONE=$(get_timezone)
-
-# Store configuration for dockeruser
-echo "FQDN=$FQDN" > /tmp/mailcow_vars
-echo "TIMEZONE=$TIMEZONE" >> /tmp/mailcow_vars
-
-configure_mailcow "$FQDN" "$TIMEZONE"
-
-su - dockeruser << 'EOF'
-# Source the configuration variables
-source /tmp/mailcow_vars
-
-# Clone and set up mailcow
-cd /opt
-git clone https://github.com/mailcow/mailcow-dockerized
-cd mailcow-dockerized
-
-# Use the prepared configuration
-cat /tmp/mailcow_config > mailcow.conf
-
-# Generate config with the provided FQDN
-printf "%s\n" "$FQDN" | ./generate_config.sh
-
-# Offer to edit the full configuration
-read -p "Would you like to review and edit the full mailcow configuration? (y/N): " edit_conf
-if [[ $edit_conf =~ ^[Yy]$ ]]; then
-    nano mailcow.conf
+    systemctl restart fail2ban
+    save_checkpoint "fail2ban_configured"
 fi
 
-# Start Mailcow
-docker compose pull
-docker compose up -d
-EOF
+# Step 4: Install and configure Mailcow
+if ! is_step_completed "mailcow_installed"; then
+    log_message "Setting up Mailcow..."
+    
+    # Check if FQDN is already set
+    if [ ! -f "/tmp/mailcow_hostname" ]; then
+        read -p "Please enter your Fully Qualified Domain Name (FQDN) (e.g., mail.example.com): " MAILCOW_HOSTNAME
+        echo "$MAILCOW_HOSTNAME" > /tmp/mailcow_hostname
+    else
+        MAILCOW_HOSTNAME=$(cat /tmp/mailcow_hostname)
+        log_message "Using saved FQDN: $MAILCOW_HOSTNAME"
+    fi
 
-# Clean up temporary files
-rm -f /tmp/mailcow_vars /tmp/mailcow_config
+    # Create mailcow directory if not exists
+    if [ ! -d "$MAILCOW_DIR" ]; then
+        mkdir -p "$MAILCOW_DIR"
+        chown dockeruser:dockeruser "$MAILCOW_DIR"
+        
+        # Clone repository
+        su - dockeruser -c "cd /opt && git clone https://github.com/mailcow/mailcow-dockerized"
+    fi
 
-# Final security checks
-log_message "Performing final security checks..."
-su - dockeruser -c "cd /opt/mailcow-dockerized && docker compose ps"
-ufw status
-systemctl status fail2ban
+    # Generate config if not already generated
+    if [ ! -f "$MAILCOW_DIR/mailcow.conf" ]; then
+        cd "$MAILCOW_DIR"
+        echo "$MAILCOW_HOSTNAME" | ./generate_config.sh
+        
+        echo "Would you like to edit the mailcow configuration? (y/N)"
+        read -n1 -r
+        echo
+        if [[ $REPLY =~ ^[Yy]$ ]]; then
+            nano mailcow.conf
+        fi
+    fi
 
-log_message "Installation complete! Please check the logs above for any errors."
-log_message "Remember to:"
-log_message "1. Change the default passwords"
-log_message "2. Configure your DNS records"
-log_message "3. Set up SSL certificates"
-log_message "4. Regular backup your configuration"
+    # Start Mailcow services
+    log_message "Starting Mailcow services..."
+    su - dockeruser -c "cd $MAILCOW_DIR && docker compose pull && docker compose up -d"
+    
+    save_checkpoint "mailcow_installed"
+fi
 
-# Print access information
-echo "================================================================"
-echo "Mailcow web interface: https://$(hostname)"
-echo "Docker user: dockeruser"
-echo "Mailcow location: /opt/mailcow-dockerized"
-echo "Firewall status:"
-ufw status numbered
-echo "================================================================"
\ No newline at end of file
+# Configure UFW if not already configured
+if ! ufw status | grep -q "Status: active"; then
+    log_message "Configuring firewall..."
+    ufw default deny incoming
+    ufw default allow outgoing
+    ufw allow 22/tcp
+    ufw allow 25/tcp
+    ufw allow 80/tcp
+    ufw allow 110/tcp
+    ufw allow 143/tcp
+    ufw allow 443/tcp
+    ufw allow 465/tcp
+    ufw allow 587/tcp
+    ufw allow 993/tcp
+    ufw allow 995/tcp
+    ufw allow 4190/tcp
+    ufw --force enable
+fi
+
+# Final steps and cleanup
+if [ "$(get_checkpoint)" = "mailcow_installed" ]; then
+    log_message "Installation completed successfully!"
+    rm -f "$CHECKPOINT_FILE" "/tmp/mailcow_hostname"
+    save_checkpoint "complete"
+    
+    # Print access information
+    echo "================================================================"
+    echo "Mailcow web interface: https://$MAILCOW_HOSTNAME"
+    echo "Docker user: dockeruser"
+    echo "Mailcow location: $MAILCOW_DIR"
+    echo "Firewall status:"
+    ufw status numbered
+    echo "================================================================"
+fi
\ No newline at end of file