Mailing lists that live with the mail

What it is

Mailman is the long-standing open-source mailing list manager. Version 3 splits the job into three parts: the core that handles subscriptions and delivery, a web interface for subscribers and list owners, and an archiver that turns every post into a browsable, searchable web page.

It handles the two kinds of list most organisations need. Announcement lists, where a few people post and everyone else reads. And discussion lists, where any member can post and the conversation is shared. People subscribe and unsubscribe themselves, choose digests if they prefer, and list owners moderate first posts or anything that looks wrong.

Why I run it instead of the SaaS alternative

Google Groups, Groups.io and the newsletter platforms such as Mailchimp all do versions of this, and they are a reasonable choice. For marketing mail with designed templates, open tracking and audience segmentation, a dedicated newsletter platform is better at that job than Mailman and I would not pretend otherwise.

Discussion lists are a different thing. I want the archive to belong to the list, not to a platform that might change its terms or close the product. I want list mail to come from my own domains, signed by my own server, so it passes the same authentication checks as my ordinary mail. And I do not want subscriber addresses sitting in a third party's database for any purpose beyond the list itself.

Running it on the same mail server as everything else also means one place to look when delivery goes wrong, rather than two systems blaming each other.

How it is set up here

1. Containers beside the mail server. The Mailman core, its web interface and its database run as their own containers on the estate server.
2. Wired into the existing mail. Postfix hands list addresses to Mailman and Mailman sends out through Postfix, so every list message goes through the same server that already passes SPF, DKIM and DMARC.
3. Per-domain lists. Lists can live on any domain the server handles, so a project's list carries that project's name.
4. Archives and self-service on the web. Subscribers manage their own settings through the web interface, behind the same single edge and TLS as everything else.
5. Backed up and monitored. Its database is in the nightly dumps that leave the server, and the web interface is in the five-minute uptime checks.

What it replaces

• Google Groups or similar hosted discussion lists.
• Long CC lines and reply-all chains that nobody can leave.
• Spreadsheets of addresses pasted into a personal mail client.

What it costs to run is mostly care. Lists are mail, and mail needs its authentication kept right, its bounces handled and its moderation queue read. Mailman automates the bounce handling; the moderation still needs a person.

What I would do for a client

First, work out what the list is for. If it is marketing, I would point you at a proper newsletter platform and make sure its sending is authenticated under your domain. If it is an announcement channel, a members' discussion, a board, or a community that needs an archive it owns, Mailman is a good fit.

Then build it properly: on your mail server or alongside your existing provider, with authentication that passes, the privacy of archives set deliberately for each list, moderation roles assigned to named people, and a short guide for list owners so it does not depend on me.

Questions people ask