Basically the title. I don’t see a Traveller group on Eternal September, so I suspect even if it was a thing on Usenet, it’s not anymore. I’m not sure how to perform a more thorough check off the top of my head.
I have no idea about Echomail.
If they existed, what were these communities like? Do they still exist and I just didn’t find them when I looked?
I guess Citizens of the Imperium is the spiritual successor to whatever communities existed before.