For an announcements list, you don’t want people replying to the list, which will reject their messages. I had to do some digging to find out where to set this in Mailman. It’s under the General Options:
Where are replies to list messages directed? Poster is strongly recommended for most mailing lists. — which lets the recipient replies go back to the list, to the poster (which is the old-fashioned way to do it on discussion lists) or you can set to go back to an explicit address — which for reasons I won’t go into right now, is the way I wanted it.
OK, so this setting probably should have been really obvious, but I only just found it. Call me slow if you like.
I agree, announcements lists could be much easier to set up. For that matter, lists of any kind should be a lot easier to create in working order.
Yes, it would make sense to have some kind of wizard thing for typical common scenarios, of which an announcements list is clearly one.