Docker

Dispatch ships as a multi-arch container image (linux/amd64 + linux/arm64), so the same tag runs natively on x86 servers and Apple Silicon. There are two common paths: a one-command local stack with Compose, or running the published image against your own SQL Server.

Try it locally with Compose

From a clone of the repository, bring up Dispatch and its database together. The Compose file uses Azure SQL Edge (arm64-native) so it works the same on any host:

docker compose up -d --build

The dashboard comes up at https://localhost:8420 with a self-signed certificate (accept the browser warning). The default login password is in docker-compose.yml - change it after your first login.

Run from GHCR

Point the published image at your own SQL Server or Azure SQL:

docker run -d --name dispatch \
  -p 8420:8420 -p 8025:8025 -p 25:25 -p 587:587 \
  -e ConnectionStrings__DispatchLog="Server=<host>,1433;Database=DispatchLog;User Id=sa;Password=<pw>;TrustServerCertificate=True;Encrypt=True" \
  -e AdminPassword="<DashboardPassword!>" \
  -v dispatch-spool:/app/.dispatch-spool \
  ghcr.io/chrismuench/dispatch-smtp-relay:latest

Only two settings are passed in: the SQL connection string and the first-run admin password. Everything else is seeded into the SQL config table and managed from the dashboard - see Configuration. The DispatchLog schema is created and migrated automatically on first start.

Ports

Port	Purpose
8420	Dashboard (HTTPS)
8025	HTTP API
25, 587	SMTP listener (the container runs as root, so it binds the standard ports; if host 25 is busy, remap e.g. -p 2525:25)

Volumes

Volume	Purpose
dispatch-spool (/app/.dispatch-spool)	Durable message queue - persists in-flight and captured mail across restarts

Allow-lists

The default source-IP allow-lists are container-aware: the dashboard and API allow all connections and are gated by the password and API keys, while the SMTP listener accepts only loopback and private (RFC1918) ranges so it isn’t an open relay. Tighten these in Settings - see Security.