Andrew Poelstra said:
This is Usenet, which is a different protocal (NNTP) than email
(SMTP). Your ISP probably has a newsserver you can use to post
messages, plus there are a number of free ones on the Internet.
Most ISPs don't have news servers these days. But yes, there are some
good free ones (I use news.eternal-september.org; aioe.org is also
pretty good).
You'll need an NNTP client; there are a number of good free ones.
Many e-mail clients also support NNTP (Thunderbird does, for example).
It is pretty hard to find a worse interface than Google's. At
the very least, others will not pretend that they "own" Usenet
and brand it using their own "Groups" service.
Actually, there are a number of other sites that do just that. A
Google search on some topic I've posted on sometimes turns up one of
my own articles in a forum I've never heard of, with no obvious
indication that it was actually posted to Usenet.