Hello!

This is only relevant for those people who read or post in that
newsgroup using Google Groups.

Google will discontinue Groups in 2024.

For those who do not know Usenet:

Usenet is a distributed communication system consisting of many servers.
Google Groups is only one of them that closes down - other servers will
stay available, but people need to use another server to read and post
here.

There are 2 alternatives:

Using a web-based Usenet interface:
Those behave similar to Google Groups, you can read there, but for
posting you need to register an account for free.

One of them is:
https://www.novabbs.com/computers/thread.php?group=comp.mail.sendmail

Another alternative is to use an NNTP server with a so called
newsreader.

As an NNTP server, some free services exist where you have to register:
https://www.eternal-september.org/
https://solani.org/
https://www.i2pn2.org/
https://news.nntp4.net/

For using it, you need a newsreader.

Some examples are:
https://www.thunderbird.net
https://www.betterbird.eu/
https://claws-mail.org/
https://www.seamonkey-project.org/

You then need to configure a newsgroup account, sometimes also
called NNTP.

For most servers, authentication must be enforced in the newsreader's
settings.

For Thunderbird, a tutorial is available here:
https://www.big-8.org/wiki/Getting_Started_with_Usenet

For questions about configuring those readers, feel free to ask in
the group news.software.readers.

Thanks, that was helpful.