I haven’t been on Usenet for ages and hadn’t realised free-usenet.com was down… Thanks for alerting me! It looks like it disappeared in early December according to a forum on Reddit.
While there are plenty of free trials around from the major Usenet providers, a quick online search hasn’t revealed anything that is permanently free (albeit slow) like free-usenet.com was. If anyone knows of a similar Usenet server, please either respond to this thread or let me know by PM and I shall update my guide.