Stalwart

Stalwart is a collaboration server with a self-hostable free tier. it provides not only email, but also calendar, contact, and filesharing support.

See also

• Homepage: https://stalw.art
• Documentation: https://stalw.art/docs/install/
• Free-tier code: https://github.com/stalwartlabs/stalwart
• Installation validity tests: Email Testers and Validators

Docker installation

For docker compose:

services:
  stalwart:
    container_name: stalwart
    image: stalwartlabs/stalwart:latest
    restart: unless-stopped
    ports:
      - "25:25"    # SMTP
      #- 110:110    # POP3
      #- 443:443    # HTTPS
      - 465:465    # SMTPS
      - 587:587    # SMTP submission (STARTTLS)
      #- 143:143    # IMAP4
      - 993:993    # IMAPS
      #- 995:995    # POP3S
      #- 4190:4190  # ManageSieve
      #- 8080:8080  # HTTPS admin interface
    volumes:
      - ./config:/etc/stalwart
      - /opt/docker/stalwart/data:/var/lib/stalwart
      - /opt/docker/stalwart/logs:/var/log/stalwart
    env_file:
      - stalwart.env
    dns:
      - 9.9.9.9
      - 1.1.1.1

and the accompanying stalwart.env:

STALWART_PUBLIC_URL=https://stalwart.staging.example.com

Make sure you set all the mounts’ to be owned by UID 2000.

Docker Compose notes

• I’ve commented out the ports that I don’t use here, but listed them anyways for reference.
  • Port 8080 is the admin interface and, if you are able to, should be made available only to trusted networks
  • Port 443 is public-facing HTTPS for web administration, JMAP, OAuth, certificate provisioning, and a few others. If you don’t map it here, you will need to set up a reverse-proxy to it.
    • If you use Caddy to do this, see Disable upstream TLS verification; it doesn’t like Stalwart’s self-signed cert.
• I had problems with Stalwart being unable to do DNS queries when starting up. I’m not sure why (haven’t had this problem with other similarly-defined compose services on this machine, nor could I find any references to it online), but specifying the dns options was enough to get it running.

Authentication

See Authentik & Stalwart.

Troubleshooting

Stalwart’s docker container doesn’t make very much noise when something goes wrong; the instinctive approach of sudo docker logs stalwart --tail=20 often just returns total silence.

Instead, you can try:

• Checking the log file in the /opt/docker/stalwart/logs folder on the host (or wherever else you mapped /var/log/stalwart to through docker).
  • This log is colorized by defailt — cat / tail are probably better ways to read it, as your console will reapply the formatting (less or vim will not, and you’ll have to read through escape codes)
• Triggering a config reload via the admin panel ⇒ Management ⇒ Actions ⇒ Reload ⇒ Server Settings. This will sometimes spit out an error message if it fails.
• Checking failed tasks via the admin panel ⇒ Management ⇒ Tasks ⇒ Failed. Select a failed task, and at the bottom of the page, inspect the Failure Reason.