> Local mail delivery does not traverse the Internet, or any network.
The implication here being that you are running the clients on the email server. Wouldn't you effectively get the same security by tunneling IMAP over SSH?
That's a common scenario, but most linux/BSD distros ship with some mail server software installed and configured to run out of the box, even if also set to not allow external connections, as that's how the system delivers messages to users (e.g. cron output, etc). So almost every linux/BSD is a mail server, even if it may not be the mail server. If there's a main box that people in your company connect to as a terminal, email to local accounts on that box is essentially a internal messaging system. Hell, you could throw an IRC server on there with no outside access and use terminal IRC clients to have your own private chat channel as well. Who needs slack?
If you want to send someone a message, there is write (if the person have mesg set to yes). There is also talk, but it requires its own daemon.
Seriously, _nix started out in the mainframe era. Meaning that the basic assumption was multiple terminals hooked up to a single computer, with a different user on each terminal.
Sadly we have a generation or more that grew up with single user computers, and seems to insist on turning _nix into that rather than embrace what it can offer.
Yes... that's the point of the discussion. They exist, but there is (or is perceived to be) lack of knowledge about their existence and how to make use of them from some newer users, either because of the push for desktop linux, or for whatever reason.
> Yet here we all are having a discussion on HN instead.
I have no idea what you're trying to imply here. I suspect maybe we are discussing similar, but ultimately different, things.
And it is not about thin clients, thin clients btw is yet another Windows-ism, it is about the concepts embedded in the unix concept that current day devs seems to either sidestep or downplay while building house of cards in userspace that poorly replicate said concepts.