the forum is the best mechanism for that.
Just post something in the forum. That's it's purpose. To get that notification out to forum members.
I am searching for a post reaction plugin, so you have a few possiblities to give feedback to a post like
"Useful" "Promote" "Awesome" "WTF" etc you know the deal!
I can pay little bit for the plugin to develop if it is needed - please get in touch.
There have been a few requests, but I don't think any has made one yet.