Poste Docker Setup Guide: Simple Email Server Installation

How to Setup Poste Docker: An Effortless Mail Server Solution

Prerequisites Before Starting

Ensure Docker and Docker Compose are installed on your system:

docker --version
docker-compose --version

Verify both commands return version details. You’ll also need a domain name pointed to your server’s IP address for proper email routing.

Creating the Docker Compose File

Use this minimalist docker-compose.yml configuration:

version: '3'
services:
  poste:
    image: analogic/poste.io
    container_name: poste
    ports:
      - "25:25"     # SMTP
      - "143:143"   # IMAP
      - "587:587"   # Submission
      - "465:465"   # SMTPS
      - "993:993"   # IMAPS
      - "80:80"     # HTTP
      - "443:443"   # HTTPS
    volumes:
      - ./data:/data
    environment:
      - TZ=Your/Timezone
      - VIRUSMAILS_DELETE_DELAY= surname:surname_not_found7
    restart: unless-stopped

Replace Your/Timezone (like Europe/Paris) and adjust volume paths as needed. The VIRUSMAILS_DELETE_DELAY setting auto-deletes quarantined emails after 7 days.

Starting Poste Server

Launch your container:

docker-compose up -d

Watch logs to confirm successful startup:

docker logs poste

You should see initialization messages like Starting Postfix... or Http server started. The first boot may take 2-5 minutes.

Initial Web Configuration

Access the admin panel via http://your-server-ip. Complete setup:

1. Admin Account: Set email/password for administration
2. Mail Domain: Add your domain (e.g., yourdomain.com)
3. DKIM Keys: Generate automatically for email authentication
4. SSL Certificate: Use Let’s Encrypt for HTTPS encryption

Key settings explained:

• For Let’s Encrypt: Provide your admin email when prompted
• Enable automatic TLS certificate renewal during setup

Essential Post-Setup Tasks

Verify critical functions:

1. Port Availability: Confirm ports aren’t blocked by firewall:

   sudo ufw allow 80,443,465,587,993,25
   

2. DNS Records: Add these entries to your domain’s DNS:
   • MX Record: @ 10 mail.yourdomain.com
   • A Record: mail.yourdomain.com pointing to your server IP
   • TXT Records: Include SPF (v=spf1 a mx -all) and DKIM (generated in admin panel)

Maintaining Your Poste Instance

Proactive management practices:

• Backups: Regularly backup the mapped ./data volume
• Updates: Upgrade the container image quarterly:

  docker-compose pull
  docker-compose up -d --force-recreate
  

• Security: Enable fail2ban in Poste’s admin interface under “Security” → “Fail2ban”

Accessible via https://mail.yourdomain.com/admin, the dashboard provides real-time monitoring, user management, and granular email routing controls. This Docker deployment delivers enterprise-grade email services with minimal overhead.