Hello Christoph,
If we setup such a system, can we assume that it will silently operate without causing much administration work most of the time (like my nginx server)? Or is maintaining a Mailman 3 server a significant burden? As with all things, it is easy once you've mastered it, and easy for someone who /has/ mastered it to say it's easy :P
It's an interesting technical challenge, but please bear in mind that you'll need to gain a reasonable level of expertise not only in configuring, deploying and maintaining Mailman3, but also the associated MTA (usually postfix) with (very probably) a SPAM filter hooked up to it. And, of course, both Django-based WebUI projects for administering (Postorius) and archiving (Hyperkitty), with associated HTTP servers and DBMSs.
The (almost-)complete list of software you'll need be familiar with to achieve any reasonable degree of success is:
- An HTTP server with WSGI backend (*Apache2 / Nginx, mod_wsgi / uwsgi*)
- An MTA for reception and sending of messages (*Postfix*)
- (Optionally) an anti-spam & DKIM-signing solution (*rspamd / amavis*)
- The *Django* Python web framework - deploying *Postorius* + *Hyperkitty* does require some TLC on this front. Familiarity deploying Django-based projects helps /immensely/.
- *MySQL / PostgreSQL* / any other supported DBMS - for the aforementioned Web UIs.
- Assorted knowledge of how email servers interoperate, in particular setting up FCrDNS, SPF records for better deliverability, possibly an understanding of DMARC/DKIM in case things ever go wrong (spoiler: yahoo does /not/ play nice with mailing lists ever since they published their DMARC policies...)
- And, of course, general SysAdmin knowledge to install the OS, set up SysV/Systemd units so everything starts up smoothly after a reboot, probably a monitoring system to get alerts & insights in case something goes wrong, etc.
The only problem is that our list runs on Mailman 2. We would like to move to Mailman 3 Why? Is there any feature you're missing in Mailman2 that Mailman3 has? If your Mailman2 installation "just works" and serves all of your needs, my advice would be to /keep it/. It's an old warhorse, but works reliably, and is maintained (so long as your hosting provider actually bothers to maintain it up-to-date, of course). E-mail technology is ancient; one hardly needs the latest version of /anything/ that is based around e-mail.
If your current ISP offers a decent service and you're happy with them, I'd definitely stay. Especially if you don't have a dedicated sysadmin profile in your project's team.
are you aware of organizations that propose Mailman 3 hosting for open source projects? If you're based in Europe, I can offer a few recommendations. I'm not comfortable with posting specific names on a public mailing list (that's tantamount to self-advertising), but feel free to ask by private reply. Regards, Daniel