Docker

RustMail ships a multi-arch Docker image supporting linux/amd64, linux/arm64, and linux/arm/v7.

Quick Start

docker run -p 1025:1025 -p 8025:8025 smyile/rustmail:latest

Docker Compose

services:
  rustmail:
    image: smyile/rustmail:latest
    ports:
      - "1025:1025"
      - "8025:8025"
    security_opt:
      - no-new-privileges:true
    volumes:
      - rustmail-data:/data
    restart: unless-stopped

volumes:
  rustmail-data:

Persistence

Mount a volume to /data to persist emails across container restarts. The image sets RUSTMAIL_DB_PATH=/data/rustmail.db and RUSTMAIL_BIND=0.0.0.0 by default.

For ephemeral (CI) usage, skip the volume:

docker run -p 1025:1025 -p 8025:8025 -e RUSTMAIL_EPHEMERAL=true smyile/rustmail:latest

Upgrading

Upgrading from 0.7 or earlier to 0.8 migrates the database in /data on the first start, before SMTP and HTTP come up. The volume must be writable and have room for the old and the new database side by side; the old one is kept as /data/rustmail.db.schema0.bak. Pin the image tag so you control when this happens. See Upgrading for timings, the health check, and how to restore the backup.

Environment Variables

All CLI flags have corresponding environment variables prefixed with RUSTMAIL_. These work in Docker Compose environment blocks, .env files, or docker run -e flags.

Optional STARTTLS

RustMail supports explicit SMTP STARTTLS on the existing SMTP listener port. To enable it in Docker, mount a certificate and key, then set both RUSTMAIL_SMTP_TLS_CERT and RUSTMAIL_SMTP_TLS_KEY.

docker run \
  -p 1025:1025 -p 8025:8025 \
  -v "$PWD/certs:/certs:ro" \
  -e RUSTMAIL_SMTP_TLS_CERT=/certs/smtp-cert.pem \
  -e RUSTMAIL_SMTP_TLS_KEY=/certs/smtp-key.pem \
  smyile/rustmail:latest

RustMail advertises STARTTLS only when both files are configured. After a client upgrades the connection, it must send EHLO again.