Some years ago I was involved with a society (club), and we wanted a webforum. But as we were geeks as well, we created a combination of a web-based solution, mail-lists and NNTP. These three solutions were syncronized, so it didn't matter which one you used. This worked well for several years.

That is a very good concept, enjoyed reading it.

On the original concept is restricted to share outside the participating people but could be relevant that people add more people that are interested in a topic.

Email is a good transport layer. Nowadays people just imagine it as messages between large providers, but I'm in strong favour that small providers or self-hosting email can still be used.