Quick start

Want to explore first? The interactive browser demo runs with made-up traffic, without installing Mailinois or Postfix.

Only want to look at a log?

mailinois report /var/log/mail.log writes one HTML report from the log you already have, with nothing to run afterwards. One-off reports.

Docker

docker run -d --name mailinois \
  -p 7480:7480 -p 5514:5514 -p 5514:5514/udp \
  -v mailinois-data:/data \
  -e MAILINOIS_DATABASE_URL=sqlite:/data/mailinois.db \
  ghcr.io/samjuk/mailinois

Port 7480 serves the dashboard, the REST API and /metrics. Port 5514 takes syslog from your Postfix hosts over TCP and UDP. The SQLite database sits on the mailinois-data volume, so it survives a new image.

Open http://localhost:7480.

There is no login until you set one up. For a single login, add -e MAILINOIS_PASSWORD=… and sign in as admin. Authentication covers the rest.

Docker Compose

compose.yaml

services:
  mailinois:
    image: ghcr.io/samjuk/mailinois
    restart: unless-stopped
    environment:
      MAILINOIS_DATABASE_URL: sqlite:/data/mailinois.db
      MAILINOIS_PASSWORD_FILE: /run/secrets/mailinois_password
    secrets: [mailinois_password]
    ports:
      - "7480:7480"       # dashboard, REST API, /metrics
      - "5514:5514"       # syslog, TCP
      - "5514:5514/udp"   # syslog, UDP
    volumes:
      - mailinois-data:/data

secrets:
  mailinois_password:
    file: ./mailinois_password.txt

volumes:
  mailinois-data:

Put the password in mailinois_password.txt next to the file, then docker compose up -d. The user name is admin.

For anything beyond the environment variables, mount a config file and point MAILINOIS_CONFIG at it:

    environment:
      MAILINOIS_CONFIG: /etc/mailinois/mailinois.yaml
    volumes:
      - mailinois-data:/data
      - ./mailinois.yaml:/etc/mailinois/mailinois.yaml:ro

The binary

Download it from a release (Linux amd64 and arm64, macOS arm64; Installing has the commands and a systemd unit), or build it with Go from a checkout (make build writes bin/mailinois), then run it:

mailinois serve

With no config file it runs on the defaults: the dashboard on port 7480, syslog on port 5514, and SQLite in mailinois.db in the working directory.

For anything more, copy deploy/config/mailinois.example.yaml from the repository, keep the parts you need and point Mailinois at it:

mailinois serve -config mailinois.yaml

The example file includes sample sites, users, a webhook and an alert. Remove the ones you don’t want, or a firing alert will be posted to the placeholder Slack URL. Configuration explains every key.

Send it some logs

On each Postfix host, copy deploy/rsyslog/mailinois.conf from the repository into /etc/rsyslog.d/, set target to Mailinois’s address and restart rsyslog:

sudo cp mailinois.conf /etc/rsyslog.d/
sudo systemctl restart rsyslog

Each server appears under its hostname when its first line arrives. Sending logs covers containers, the agent for servers on other networks, and importing old logs.

Try the local preview

The repository has a compose file that runs everything on your machine, with made-up traffic to look at. In a checkout:

docker compose up -d --build

• Dashboard: http://localhost:7480
• Mailpit, where the local Postfix delivers: http://localhost:8325

Mailinois runs in demo mode on SQLite: two weeks of made-up traffic from two relays (including a Microsoft reputation incident three days ago and a dead mail server), with a new message every few seconds.

Alongside it runs a real Postfix (boky/postfix) that forwards its log to Mailinois, hands every message to Mailinois’s capture milter, and relays everything to Mailpit, so nothing leaves your machine. Send it a real message:

make mail TO=someone@example.com

It shows up on the Messages page under the server postfix-local, with its headers and body captured, and in Mailpit. docker compose down stops it all.