I just upgraded from Ubuntu 21.04 to Ubuntu 21.10.
Baring a few glitches here and there, it's now running ok.
However, I just discovered that Thunderbird 91.x.x removed movemail support! That means that I've lost support for my /var/mail/* mboxes!
Other than installing another mail program, like possibly
Evolution, is there any way to get to my mboxes again?