This configuration is intended to be used with a Mailu instance which is setup on the same VPS. A shared volume (Mailman core generated aliases for mail delivery) and a shared network (Mailu and Mailman can then see each other) are used to ensure that the postfix service in the Mailu stack can handle incoming and outgoing mail for Mailman.

This configuration assumes the following:

a working Mailu instance (e.g. mail.example.com)
a MX and SPF domain record for your mailing list domain (e.g. lists.example.com) ponting to your Mailu instance for incoming mail (e.g. mail.example.com)
the mailman-core container IP range configured in the RELAYNETS environment variable on the Mailu side for outgoing mail relaying (ensure you do not an open relay using a tool like mxtoolbox)
overlay networks configured for both the Mailu and Mailman3 stacks (see SMTP_HOST and SMTP_NETWORK in the .env.sample and MAILMAN_CORE_NETWORK in the Mailu config)
a shared volume between your Mailman3 and Mailu stack which exposes the Mailman generated aliases to Mailu (see MAILMAN_CORE_VOLUME in the mailu config)

Basic usage

Set up Docker Swarm and abra
Deploy coop-cloud/traefik
abra app new mailman3 --secrets (optionally with --pass if you'd like to save secrets in pass)
abra app YOURAPPDOMAIN config - be sure to change $DOMAIN to something that resolves to your Docker swarm box
abra app YOURAPPDOMAIN deploy
Open the configured domain in your browser to finish set-up