Yeah, I'm old too. I subscribed to INFO-COBOL@MC (which was not about COBOL, but used that name because joke mailing lists were forbidden on the ARPANET), DB-LOVERS@MC (maintained by the tty of Geoffrey S. Goodfellow, specializing in dead baby jokes, not databases), ITS-LOVERS@MC aka UNIX-HATERS@MC, and I also ran a large international mailing list NeWS-makers@brillig.umd.edu, with lots of redistribution lists as well as usenet subscribers (routed via uunet) for many years during the 80's.

My point is that an email message that has a bunch of people's addressed in it, but no central server or list of email addresses, which you reply to by copying all the addresses in the To: and CC: fields, is not a mailing list, no matter how sophisticated your email reader is. It's just an email message, and you're doing all of the work in your email reader. (Hello, Emacs!) That's not a mailing list. It's just an email message with a list of recipients. There's nothing preventing any recipient from adding or removing any address from the list, and there's no central archive or administration or moderation.

Here's what mailing lists looked like in the 80's:

http://its.svensson.org/.MAIL.%3B.MCNEW

Who remembers Mark Crispin's oft-repeated catch phrase, "MM is not at fault!"

JWZ's Law of Software Envelopment: Every program attempts to expand until it can read mail. Those programs which cannot so expand are replaced by ones which can.