After fretting about a few annoying bugs in Pine v4.21, an older version installed at Dreamhost, superstar Dreamhost tech supporter William not only suggested I just download and build my own copy of the latest version (why didn't I think of that?), but also pointed me to this list of patches for Pine-- especially the fancy threads patch. I can't believe I lived so long without Pine v4.44, let alone the fancy threads feature. See also the excellent Pine FAQ at this site.

I'm still waiting for a patch/new feature to list the number of new messages in each folder in the folder list, so I don't have to go folder diving just to look for new messages. Perhaps it's already there, and I've overlooked it? (I was only recently made aware that the message list is highly customizable by editing the config file.) I'd gladly use tab-to-next-folder-with-new-messages, but I never got it to work for me. Perhaps I just need to switch email programs.