Peter Duniho wrote:
It still surprises me. I just can't imagine a newsreader trying to take
itself seriously without that feature.

Well, I checked around, and found a variety of mentions that this just
isn't available in Thunderbird. The netscape.public.mozilla.mail-news
newsgroup in particular has some illuminating comments.

I am also surprised that, even if this functionality is missing from the
basic application, that there's no extension to provide it. There are
all sorts of extensions for all sorts of other things, including a lot
of relatively useless stuff. But nothing to add this very basic, very
necessary newsreader feature.

I find the whole thing ironic.

Pete