MailScanner is a free and open-source Mail Security. Email security system for mail gateways

Hardware Requirements:

CPU: 2 cores minimum (4+ cores recommended)

RAM: 2GB minimum (4GB+ recommended)

Storage: 1GB for installation

Network: 25 ports

Operating System:

Linux: Any modern distribution (RHEL, Debian, Ubuntu, CentOS, Fedora, Arch, Alpine, openSUSE)

macOS: 10.14+ (Mojave or newer)

Windows: Windows Server 2016+ or Windows 10

FreeBSD: 11.0+

Network Requirements:

Port 25 (default mailscanner port)

Dependencies:

perl, spamassassin, clamav

System Access: root or sudo privileges required

This guide supports installation on:

RHEL 8/9 and derivatives (CentOS Stream, Rocky Linux, AlmaLinux)

Debian 11/12

Ubuntu 20.04/22.04/24.04 LTS

Arch Linux (rolling release)

Alpine Linux 3.18+

openSUSE Leap 15.5+ / Tumbleweed

SUSE Linux Enterprise Server (SLES) 15+

macOS 12+ (Monterey and later)

FreeBSD 13+

Windows 10/11/Server 2019+ (where applicable)

bash

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

# Install mailscanner
sudo dnf install -y mailscanner perl, spamassassin, clamav

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

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

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

bash

# Update package index
sudo apt update

# Install mailscanner
sudo apt install -y mailscanner perl, spamassassin, clamav

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

# Configure firewall
sudo ufw allow 25

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

bash

# Install mailscanner
sudo pacman -S mailscanner

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

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

bash

# Install mailscanner
apk add --no-cache mailscanner

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

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

bash

# Install mailscanner
sudo zypper install -y mailscanner perl, spamassassin, clamav

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

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

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

bash

# Using Homebrew
brew install mailscanner

# Start service
brew services start mailscanner

# Verify installation
mailscanner --version

bash

# Using pkg
pkg install mailscanner

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

# Start service
service mailscanner start

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

powershell

# Using Chocolatey
choco install mailscanner

# Or using Scoop
scoop install mailscanner

# Verify installation
mailscanner --version

bash

# Create configuration directory if needed
sudo mkdir -p /etc/MailScanner

# Set up basic configuration
sudo tee /etc/MailScanner/mailscanner.conf << 'EOF'
# MailScanner Configuration
Max Children = 5
EOF

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

# Reload service
sudo systemctl reload mailscanner

bash

# Set appropriate permissions
sudo chown -R mailscanner:mailscanner /etc/MailScanner
sudo chmod 750 /etc/MailScanner

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

bash

# Enable service
sudo systemctl enable mailscanner

# Start service
sudo systemctl start mailscanner

# Stop service
sudo systemctl stop mailscanner

# Restart service
sudo systemctl restart mailscanner

# Reload configuration
sudo systemctl reload mailscanner

# Check status
sudo systemctl status mailscanner

# View logs
sudo journalctl -u mailscanner -f

bash

# Enable service
rc-update add mailscanner default

# Start service
rc-service mailscanner start

# Stop service
rc-service mailscanner stop

# Restart service
rc-service mailscanner restart

# Check status
rc-service mailscanner status

bash

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

# Start service
service mailscanner start

# Stop service
service mailscanner stop

# Restart service
service mailscanner restart

# Check status
service mailscanner status

bash

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

# Check status
brew services list | grep mailscanner

powershell

# Start service
net start mailscanner

# Stop service
net stop mailscanner

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

# Check status
Get-Service mailscanner

bash

# Configure performance settings
cat >> /etc/MailScanner/mailscanner.conf << 'EOF'
Max Children = 5
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 mailscanner

bash

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

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

nginx

upstream mailscanner_backend {
    server 127.0.0.1:25;
    server 127.0.0.1:{default_port}1 backup;
}

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

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

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

    location / {
        proxy_pass http://mailscanner_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";
    }
}

apache

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

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

haproxy

frontend mailscanner_frontend
    bind *:80
    bind *:443 ssl crt /etc/ssl/certs/mailscanner.pem
    redirect scheme https if !{ ssl_fc }
    default_backend mailscanner_backend

backend mailscanner_backend
    balance roundrobin
    option httpchk GET /health
    server mailscanner1 127.0.0.1:25 check
    server mailscanner2 127.0.0.1:{default_port}1 check backup

bash

# Set appropriate permissions
sudo chown -R mailscanner:mailscanner /etc/MailScanner
sudo chmod 750 /etc/MailScanner

# Configure firewall
sudo firewall-cmd --permanent --add-service=mailscanner
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/mailscanner.conf << 'EOF'
[mailscanner]
enabled = true
port = 25
filter = mailscanner
logpath = /var/log/mailscanner/*.log
maxretry = 5
bantime = 3600
EOF

bash

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

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

PostgreSQL Backend (if applicable)

bash

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

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

bash

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

bash

# 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

# MailScanner specific tuning
Max Children = 5

bash

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

yaml

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

bash

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

bash

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

bash

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

mkdir -p "$BACKUP_DIR"

# Stop service (if required)
systemctl stop mailscanner

# Backup configuration
tar -czf "$BACKUP_DIR/mailscanner-config-$DATE.tar.gz" /etc/MailScanner

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

# Start service
systemctl start mailscanner

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

echo "Backup completed: $BACKUP_DIR"

bash

# Stop service
sudo systemctl stop mailscanner

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

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

# Set permissions
sudo chown -R mailscanner:mailscanner /etc/MailScanner
sudo chown -R mailscanner:mailscanner /var/lib/mailscanner

# Start service
sudo systemctl start mailscanner

1. Service won't start:

bash

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

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

# Check permissions
ls -la /etc/MailScanner
ls -la /var/lib/mailscanner

2. Connection refused:

bash

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

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

# Test connection
telnet localhost 25
nc -zv localhost 25

3. Performance issues:

bash

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

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

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

bash

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

# Increase log verbosity
# Edit configuration to enable debug logging

yaml

version: '3.8'
services:
  mailscanner:
    image: mailscanner:latest
    container_name: mailscanner
    ports:
      - "25:25"
    volumes:
      - ./config:/etc/MailScanner
      - ./data:/var/lib/mailscanner
    environment:
      - mailscanner_CONFIG=/etc/MailScanner/mailscanner.conf
    restart: unless-stopped
    networks:
      - mailscanner_net

networks:
  mailscanner_net:
    driver: bridge

yaml

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

yaml

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

Maintenance

bash

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

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

# Arch Linux
sudo pacman -Syu mailscanner

# Alpine Linux
apk update && apk upgrade mailscanner

# openSUSE
sudo zypper update mailscanner

# FreeBSD
pkg update && pkg upgrade mailscanner

# Always backup before updates
tar -czf /backup/mailscanner-pre-update-$(date +%Y%m%d).tar.gz /etc/MailScanner

# Restart after updates
sudo systemctl restart mailscanner

Regular Maintenance Tasks

bash

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

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

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

# Optimize performance
sudo mailscanner-optimize

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

Official Documentation: https://docs.mailscanner.org/

GitHub Repository: https://github.com/mailscanner/mailscanner

Community Forum: https://forum.mailscanner.org/

Wiki: https://wiki.mailscanner.org/

Comparison vs Amavisd-new, MIMEDefang, ASSP: https://docs.mailscanner.org/comparison

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Note: This guide is part of the HowToMgr collection. Always refer to official documentation for the most up-to-date information.

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Amavisd-new Installation Guide

MailScanner Installation Guide