Getting started

MailLaser receives emails via SMTP and instantly forwards them as structured JSON payloads to any webhook URL you configure. No mailbox, no storage, no complexity.

MailLaser bridges the gap between email and modern webhook-based systems. Point incoming emails at MailLaser, and it converts them into HTTP POST requests that services like Slack, Discord, Zapier, or your own API can consume directly.

Why MailLaser?

Most applications that need to react to incoming emails face the same problem: setting up a full mail server or parsing raw SMTP traffic is complex and error-prone. MailLaser eliminates that complexity by doing one thing well.

• Webhook-native: Every email becomes a JSON POST request. Integrate with any HTTP endpoint.
• Zero storage: Emails are parsed and forwarded immediately. Nothing is written to disk.
• Resilient delivery: Built-in retry with exponential backoff and a circuit breaker protect your webhook endpoint from cascading failures.
• Lightweight: A single static binary under 5 MB. Runs on scratch Docker images.
• STARTTLS support: Accepts encrypted SMTP connections with auto-generated self-signed certificates.

Quick start

The fastest way to run MailLaser is with Docker. You need two things: a list of email addresses to accept and a webhook URL to forward them to.

Run with Docker

docker run -d \
  --name mail-laser \
  -p 2525:2525 \
  -p 8080:8080 \
  -e MAIL_LASER_TARGET_EMAILS="alerts@example.com" \
  -e MAIL_LASER_WEBHOOK_URL="https://your-api.com/webhook" \
  ghcr.io/govcraft/mail-laser:latest

This starts MailLaser listening for SMTP on port 2525 and serving a health check on port 8080.

Send a test email

Use swaks (the Swiss Army Knife for SMTP) to verify everything works:

swaks \
  --to alerts@example.com \
  --from test@sender.com \
  --server localhost:2525 \
  --header "Subject: Test from swaks" \
  --body "Hello from MailLaser!"

Your webhook endpoint receives a JSON payload like this:

{
  "sender": "test@sender.com",
  "recipient": "alerts@example.com",
  "subject": "Test from swaks",
  "body": "Hello from MailLaser!"
}

How it works

MailLaser operates as a pipeline with four stages:

1. Listen -- The SMTP server accepts connections on the configured port (default 2525).
2. Validate -- Each RCPT TO address is checked against your configured target emails. Non-matching recipients are rejected with a 550 response.
3. Parse -- The email data is parsed to extract sender, recipient, subject, plain text body, and optionally the HTML body and matching headers.
4. Forward -- The extracted data is serialized to JSON and sent as an HTTP POST to your webhook URL with automatic retries and circuit breaker protection.

A separate health check server runs on port 8080, responding to GET /health with a 200 status for monitoring integration.

Next steps

• Install MailLaser using your preferred method
• Configure environment variables for your deployment
• Understand the webhook payload your endpoint will receive