>>529Messages (and everything else, for that matter) can be sent through Tor, but that's only if you configure a Tor proxy on your system, and configure Tox to connect through that. Otherwise, messages are sent directly to the other clients. But either way, there's no central server that handles all the messages.
Tor support is there for those who want to conceal their location, as the direct client-to-client (non-Tor) communication means sharing your IP address with the people you're talking to.
If you're just looking to chat with people, you could add groupbot@toxme.se as a friend, and use that to get invited to the official "public" groupchat/s.