Qmail Installation Guide

# Install EPEL repository if needed
sudo dnf install -y epel-release

# Install qmail
sudo dnf install -y qmail ucspi-tcp, daemontools

# Enable and start service
sudo systemctl enable --now qmail

# Configure firewall
sudo firewall-cmd --permanent --add-service=qmail
sudo firewall-cmd --reload

# Verify installation
qmail --version || systemctl status qmail

# Update package index
sudo apt update

# Install qmail
sudo apt install -y qmail ucspi-tcp, daemontools

# Enable and start service
sudo systemctl enable --now qmail

# Configure firewall
sudo ufw allow 25/587

# Verify installation
qmail --version || systemctl status qmail

# Install qmail
sudo pacman -S qmail

# Enable and start service
sudo systemctl enable --now qmail

# Verify installation
qmail --version || systemctl status qmail

# Install qmail
apk add --no-cache qmail

# Enable and start service
rc-update add qmail default
rc-service qmail start

# Verify installation
qmail --version || rc-service qmail status

# Install qmail
sudo zypper install -y qmail ucspi-tcp, daemontools

# Enable and start service
sudo systemctl enable --now qmail

# Configure firewall
sudo firewall-cmd --permanent --add-service=qmail
sudo firewall-cmd --reload

# Verify installation
qmail --version || systemctl status qmail

# Using Homebrew
brew install qmail

# Start service
brew services start qmail

# Verify installation
qmail --version

# Using pkg
pkg install qmail

# Enable in rc.conf
echo 'qmail_enable="YES"' >> /etc/rc.conf

# Start service
service qmail start

# Verify installation
qmail --version || service qmail status

# Using Chocolatey
choco install qmail

# Or using Scoop
scoop install qmail

# Verify installation
qmail --version

# Create configuration directory if needed
sudo mkdir -p /var/qmail/control

# Set up basic configuration
sudo tee /var/qmail/control/qmail.conf << 'EOF'
# Qmail Configuration
concurrencyremote = 255
EOF

# Test configuration
sudo qmail -t || sudo qmail configtest

# Reload service
sudo systemctl reload qmail

# Set appropriate permissions
sudo chown -R qmail:qmail /var/qmail/control
sudo chmod 750 /var/qmail/control

# Enable security features
# See security section for detailed hardening steps

# Enable service
sudo systemctl enable qmail

# Start service
sudo systemctl start qmail

# Stop service
sudo systemctl stop qmail

# Restart service
sudo systemctl restart qmail

# Reload configuration
sudo systemctl reload qmail

# Check status
sudo systemctl status qmail

# View logs
sudo journalctl -u qmail -f

# Enable service
rc-update add qmail default

# Start service
rc-service qmail start

# Stop service
rc-service qmail stop

# Restart service
rc-service qmail restart

# Check status
rc-service qmail status

# Enable in /etc/rc.conf
echo 'qmail_enable="YES"' >> /etc/rc.conf

# Start service
service qmail start

# Stop service
service qmail stop

# Restart service
service qmail restart

# Check status
service qmail status

# Using Homebrew services
brew services start qmail
brew services stop qmail
brew services restart qmail

# Check status
brew services list | grep qmail

# Start service
net start qmail

# Stop service
net stop qmail

# Using PowerShell
Start-Service qmail
Stop-Service qmail
Restart-Service qmail

# Check status
Get-Service qmail

# Configure performance settings
cat >> /var/qmail/control/qmail.conf << 'EOF'
concurrencyremote = 255
EOF

# Apply system tuning
sudo sysctl -w net.core.somaxconn=65535
sudo sysctl -w net.ipv4.tcp_max_syn_backlog=65535

# Restart service
sudo systemctl restart qmail

# Configure clustering (if supported)
# See official documentation for cluster setup

# Basic load balancing setup example
# Configure multiple instances on different ports

upstream qmail_backend {
    server 127.0.0.1:25/587;
    server 127.0.0.1:{default_port}1 backup;
}

server {
    listen 80;
    server_name qmail.example.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443 ssl http2;
    server_name qmail.example.com;

    ssl_certificate /etc/ssl/certs/qmail.example.com.crt;
    ssl_certificate_key /etc/ssl/private/qmail.example.com.key;

    location / {
        proxy_pass http://qmail_backend;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;
        
        # WebSocket support (if needed)
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
    }
}

<VirtualHost *:80>
    ServerName qmail.example.com
    Redirect permanent / https://qmail.example.com/
</VirtualHost>

<VirtualHost *:443>
    ServerName qmail.example.com
    
    SSLEngine on
    SSLCertificateFile /etc/ssl/certs/qmail.example.com.crt
    SSLCertificateKeyFile /etc/ssl/private/qmail.example.com.key
    
    ProxyRequests Off
    ProxyPreserveHost On
    
    ProxyPass / http://127.0.0.1:25/587/
    ProxyPassReverse / http://127.0.0.1:25/587/
    
    # WebSocket support (if needed)
    RewriteEngine on
    RewriteCond %{HTTP:Upgrade} websocket [NC]
    RewriteCond %{HTTP:Connection} upgrade [NC]
    RewriteRule ^/?(.*) "ws://127.0.0.1:25/587/$1" [P,L]
</VirtualHost>

frontend qmail_frontend
    bind *:80
    bind *:443 ssl crt /etc/ssl/certs/qmail.pem
    redirect scheme https if !{ ssl_fc }
    default_backend qmail_backend

backend qmail_backend
    balance roundrobin
    option httpchk GET /health
    server qmail1 127.0.0.1:25/587 check
    server qmail2 127.0.0.1:{default_port}1 check backup

# Set appropriate permissions
sudo chown -R qmail:qmail /var/qmail/control
sudo chmod 750 /var/qmail/control

# Configure firewall
sudo firewall-cmd --permanent --add-service=qmail
sudo firewall-cmd --reload

# Enable SELinux policies (if applicable)
sudo setsebool -P httpd_can_network_connect on

# Configure fail2ban
sudo tee /etc/fail2ban/jail.d/qmail.conf << 'EOF'
[qmail]
enabled = true
port = 25/587
filter = qmail
logpath = /var/log/qmail/*.log
maxretry = 5
bantime = 3600
EOF

# Generate SSL certificates
sudo openssl req -x509 -nodes -days 365 -newkey rsa:2048 \
    -keyout /etc/ssl/private/qmail.key \
    -out /etc/ssl/certs/qmail.crt

# Configure SSL in qmail
# See official documentation for SSL configuration

# Create database and user
sudo -u postgres psql << EOF
CREATE DATABASE qmail_db;
CREATE USER qmail_user WITH ENCRYPTED PASSWORD 'secure_password';
GRANT ALL PRIVILEGES ON DATABASE qmail_db TO qmail_user;
EOF

# Configure qmail to use PostgreSQL
# See official documentation for database configuration

# Create database and user
sudo mysql << EOF
CREATE DATABASE qmail_db;
CREATE USER 'qmail_user'@'localhost' IDENTIFIED BY 'secure_password';
GRANT ALL PRIVILEGES ON qmail_db.* TO 'qmail_user'@'localhost';
FLUSH PRIVILEGES;
EOF

# Kernel parameters
sudo tee -a /etc/sysctl.conf << EOF
net.core.somaxconn = 65535
net.ipv4.tcp_max_syn_backlog = 65535
net.ipv4.ip_local_port_range = 1024 65535
net.core.netdev_max_backlog = 5000
vm.swappiness = 10
EOF

sudo sysctl -p

# Qmail specific tuning
concurrencyremote = 255

# Configure system limits
sudo tee -a /etc/security/limits.conf << EOF
qmail soft nofile 65535
qmail hard nofile 65535
qmail soft nproc 32768
qmail hard nproc 32768
EOF

# prometheus.yml configuration
scrape_configs:
  - job_name: 'qmail'
    static_configs:
      - targets: ['localhost:25/587']
    metrics_path: '/metrics'

# Basic health check script
#!/bin/bash
if systemctl is-active --quiet qmail; then
    echo "Qmail is running"
    exit 0
else
    echo "Qmail is not running"
    exit 1
fi

# Configure log rotation
sudo tee /etc/logrotate.d/qmail << 'EOF'
/var/log/qmail/*.log {
    daily
    rotate 14
    compress
    delaycompress
    missingok
    notifempty
    create 0640 qmail qmail
    postrotate
        systemctl reload qmail > /dev/null 2>&1 || true
    endscript
}
EOF

#!/bin/bash
# Qmail backup script
BACKUP_DIR="/backup/qmail"
DATE=$(date +%Y%m%d_%H%M%S)

mkdir -p "$BACKUP_DIR"

# Stop service (if required)
systemctl stop qmail

# Backup configuration
tar -czf "$BACKUP_DIR/qmail-config-$DATE.tar.gz" /var/qmail/control

# Backup data (adjust paths as needed)
tar -czf "$BACKUP_DIR/qmail-data-$DATE.tar.gz" /var/lib/qmail

# Start service
systemctl start qmail

# Clean old backups (keep 30 days)
find "$BACKUP_DIR" -name "*.tar.gz" -mtime +30 -delete

echo "Backup completed: $BACKUP_DIR"

# Stop service
sudo systemctl stop qmail

# Restore configuration
sudo tar -xzf /backup/qmail/qmail-config-*.tar.gz -C /

# Restore data
sudo tar -xzf /backup/qmail/qmail-data-*.tar.gz -C /

# Set permissions
sudo chown -R qmail:qmail /var/qmail/control
sudo chown -R qmail:qmail /var/lib/qmail

# Start service
sudo systemctl start qmail

# Check logs
sudo journalctl -u qmail -n 100
sudo tail -f /var/log/qmail/*.log

# Check configuration
sudo qmail -t || sudo qmail configtest

# Check permissions
ls -la /var/qmail/control
ls -la /var/lib/qmail

# Check if service is listening
sudo ss -tlnp | grep 25/587
sudo netstat -tlnp | grep 25/587

# Check firewall
sudo firewall-cmd --list-all
sudo iptables -L -n

# Test connection
telnet localhost 25/587
nc -zv localhost 25/587

# Check resource usage
top -p $(pgrep qmail-send)
htop -p $(pgrep qmail-send)

# Check connections
ss -ant | grep :25/587 | wc -l

# Monitor I/O
iotop -p $(pgrep qmail-send)

# Run in debug mode
sudo qmail -d
# or
sudo qmail debug

# Increase log verbosity
# Edit configuration to enable debug logging

version: '3.8'
services:
  qmail:
    image: qmail:latest
    container_name: qmail
    ports:
      - "25/587:25/587"
    volumes:
      - ./config:/var/qmail/control
      - ./data:/var/lib/qmail
    environment:
      - qmail_CONFIG=/var/qmail/control/qmail.conf
    restart: unless-stopped
    networks:
      - qmail_net

networks:
  qmail_net:
    driver: bridge

apiVersion: apps/v1
kind: Deployment
metadata:
  name: qmail
spec:
  replicas: 3
  selector:
    matchLabels:
      app: qmail
  template:
    metadata:
      labels:
        app: qmail
    spec:
      containers:
      - name: qmail
        image: qmail:latest
        ports:
        - containerPort: 25/587
        volumeMounts:
        - name: config
          mountPath: /var/qmail/control
      volumes:
      - name: config
        configMap:
          name: qmail-config
---
apiVersion: v1
kind: Service
metadata:
  name: qmail
spec:
  selector:
    app: qmail
  ports:
  - port: 25/587
    targetPort: 25/587
  type: LoadBalancer

---
- name: Install and configure Qmail
  hosts: all
  become: yes
  tasks:
    - name: Install qmail
      package:
        name: qmail
        state: present
    
    - name: Configure qmail
      template:
        src: qmail.conf.j2
        dest: /var/qmail/control/qmail.conf
        owner: qmail
        group: qmail
        mode: '0640'
      notify: restart qmail
    
    - name: Start and enable qmail
      systemd:
        name: qmail
        state: started
        enabled: yes
  
  handlers:
    - name: restart qmail
      systemd:
        name: qmail
        state: restarted

# RHEL/CentOS/Rocky/AlmaLinux
sudo dnf update qmail

# Debian/Ubuntu
sudo apt update && sudo apt upgrade qmail

# Arch Linux
sudo pacman -Syu qmail

# Alpine Linux
apk update && apk upgrade qmail

# openSUSE
sudo zypper update qmail

# FreeBSD
pkg update && pkg upgrade qmail

# Always backup before updates
tar -czf /backup/qmail-pre-update-$(date +%Y%m%d).tar.gz /var/qmail/control

# Restart after updates
sudo systemctl restart qmail

# Clean logs
find /var/log/qmail -name "*.log" -mtime +30 -delete

# Verify integrity
sudo qmail --verify || sudo qmail check

# Update databases (if applicable)
sudo qmail-update-db

# Optimize performance
sudo qmail-optimize

# Check for security updates
sudo qmail --security-check