NNTP. It was and still is the best solution out there. I guess the reason it never took off was that the backend mindshare and software ecosystem was poor. That is, anybody can and does write specialized web servers and web pages. But if you want to implemented specialized topic group management, you're stuck reimplementing the entire NNTP stack from top to bottom, at which point people would rather just create an ad hoc protocol over HTTP.

The downside to doing everything over HTTP is that you're completely proprietary until someone else implements your protocol--but they never will, because like with NNTP it's just easier to create their own standard. NNTP still has fairly rich client support within many modern e-mail clients.

I look forward to testing this. We've not found an optimal solution since moving off FirstClass BBS years ago (price and an every growing bloat of unneeded features).

Biggest FirstClass features we miss: - Asynchronous (don't need to respond in realtime). - Threads within topics/folders. - Ability to mark item as unread. - Confirmation that message had been read.

That ability to mark item as unread was extremely useful. I'd frequently read something, see it is important, but will take time to do. Simply, mark as unread and go on with life. It is there waiting later in the day (or tomorrow). The message originator knows I've seen the message.

Threads on Slack are clumsy. Tried using them and quickly abandoned them.