Quick Start

This guide will help you deploy VaultSandbox and send your first test email in under 5 minutes using VSX DNS - automatic domain assignment with no DNS configuration required.

Prerequisites Checklist

Before you begin, ensure you have:

• Docker and Docker Compose installed
• Public IP address with ports 25, 80, and 443 accessible (no NAT/firewall blocking)

That’s it! No domain registration or DNS configuration needed.

Need a Custom Domain?

If you need to use your own domain for branding or compliance, see the Custom Domain Quick Start.

Step 1: Create Docker Compose Configuration

Create a new directory for VaultSandbox:

mkdir vaultsandbox && cd vaultsandbox

Create a docker-compose.yml file with just 1 environment variable:

services:
  gateway:
    image: vaultsandbox/gateway:latest
    container_name: vaultsandbox-gateway
    restart: unless-stopped

    ports:
      - '25:25' # SMTP
      - '80:80' # HTTP (ACME + VSX verification)
      - '443:443' # HTTPS (Web UI + API)

    environment:
      VSB_VSX_DNS_ENABLED: 'true'

    volumes:
      - gateway-data:/app/data

    healthcheck:
      test: ['CMD', 'curl', '-f', 'http://localhost:80/health']
      interval: 30s
      timeout: 10s
      retries: 3
      start_period: 40s

volumes:
  gateway-data:

Everything is Automatic

With VSX DNS enabled, VaultSandbox automatically handles:

• Domain assignment (e.g., 1mzhr2y.vsx.email)
• DNS configuration with proper MX records
• TLS certificate provisioning via Let’s Encrypt
• API key generation
• Email retention (1 hour default, configurable up to 7 days)

Step 2: Start VaultSandbox

docker compose up -d

Check that the service is running:

docker compose ps

You should see the vaultsandbox-gateway container running.

Step 3: Discover Your Domain

Your domain is automatically assigned based on your public IP. Find it by:

Option A: Enter your IP at vsx.email

Option B: Check the certificate metadata:

docker compose exec gateway cat /app/data/certificates/metadata.json; echo

Your domain will look like 1mzhr2y.vsx.email.

Retrieve your auto-generated API key:

docker compose exec gateway cat /app/data/.api-key; echo

Step 4: Access the Web UI

Open your browser and navigate to:

https://YOUR-DOMAIN.vsx.email/app

Automatic HTTPS

VaultSandbox automatically provisions Let’s Encrypt certificates on first run. This may take a minute. Once ready, the web UI will be available at the /app path with full HTTPS encryption.

You’ll be prompted to enter your API key:

Step 5: Create Your First Inbox

In the web UI:

1. Click “Create Inbox” button
2. Copy the generated email address (e.g., [email protected])
3. Your inbox is ready to receive emails

That’s it! Your inbox will automatically capture any emails sent to that address.

Step 6: Send a Test Email

Send a test email to your inbox address using any email client or SMTP tool:

# Using swaks (SMTP testing tool)
swaks --to [email protected] \
      --from [email protected] \
      --server 1mzhr2y.vsx.email \
      --port 25 \
      --h-Subject "Test Email" \
      --body "Hello from VaultSandbox!"

Or simply use your regular email client (Gmail, Outlook, etc.) and send to the inbox address.

Step 7: View Your Email

Go back to the web UI and you should see your email appear in the inbox:

Click on it to view:

• Full email content (HTML and plain text)
• All headers
• Extracted links
• Authentication results (SPF, DKIM, DMARC)
• Attachments

Verify Production Parity

To confirm VaultSandbox is testing like production, check the authentication results:

1. Send an email from a domain you control with proper SPF/DKIM setup
2. View the email in VaultSandbox
3. Check the Authentication section
4. You should see real SPF, DKIM, and DMARC verdicts

Authentication Always Failing?

If authentication checks are failing, it means your sending domain doesn’t have proper SPF/DKIM/DMARC records. This is exactly the kind of issue VaultSandbox helps you catch before production!

Next Steps

Now that VaultSandbox is running, explore more features:

• Architecture Overview - Understand how the zero-knowledge encryption works
• Custom Domain Setup - Use your own domain instead of VSX DNS
• Node.js Client Documentation - Integrate email testing into your automated tests
• Testing Patterns - Learn best practices for testing transactional emails

Troubleshooting

Domain Not Assigned

1. Check ports are accessible: Ports 25, 80, and 443 must be publicly reachable

   # From another machine, test connectivity
   nc -zv YOUR_SERVER_IP 25
   nc -zv YOUR_SERVER_IP 80
   nc -zv YOUR_SERVER_IP 443

2. Check logs:

   docker compose logs gateway

3. Verify VSX DNS is enabled: Ensure VSB_VSX_DNS_ENABLED: 'true' is set

Emails Not Arriving

1. Check SMTP Port: Ensure port 25 is not blocked by your hosting provider

   telnet YOUR-DOMAIN.vsx.email 25

2. Check Logs:

   docker compose logs gateway

Can’t Access Web UI

1. Check if service is running:

   docker compose ps

2. Check logs:

   docker compose logs gateway

3. Verify HTTPS is ready: Check logs for “Certificate obtained successfully”

4. Try HTTP first: If HTTPS isn’t working yet, try http://YOUR-DOMAIN.vsx.email/app

Need Help?

• Learn more about VSX DNS at vsx.email
• Open an issue on GitHub
• Review the deployment documentation for more configuration options

Resources

• Website: www.vaultsandbox.com
• VSX DNS: vsx.email
• Documentation: vaultsandbox.dev
• GitHub Gateway: github.com/vaultsandbox/gateway
• Docker Hub: hub.docker.com/r/vaultsandbox/gateway