Recently I've come across Discord.
It is mainly used for chatting.
It'll be somewhat like the Chat-box with emojis, and media sharing like drag and drop files and links.
As it is mobile friendly, it is easier to keep users involved and constantly check in.
Give it a try, if you want to. Very easy to setup and go. Bots can be added as well for further entertainment.
Maybe it'll be something to get the old people back. Once you send a mass Admin announcement. People still having access to their emails can check it out