There's only one solution worth considering if you do self-host, and that is mailman. It's great software. Not fancy, not bling, and development is almost non-existent because it reached "finished" some years ago. It's a stable as software gets and great support exists.
I run a few lists with mailman for work. I've integrated them with our main management software so it automatically adds and removed names for half a dozen or so lists and there's no ongoing problems. Management is trivial once it's set up.
Setup was a case of reading a guide and adding some hooks into exim4's config. Configuration is a mix of CLI and web settings. The users obviously don't have to exist locally, so you don't need imap/pop3 - just the ability to send and receive email without acting as an open relay.
