Well, I’ve done the first two steps and all seems to be OK except SpamSieve isn’t catching any spam. I have to manually identify every one. When I ask it to Show Corpus, it shows all the stuff brought over from the old machine, but doesn’t appear to be identifying anything on it’s own.
I launched Mail on the old machine, and SS catches stuff this installation is not, so it’s something with this installation. Maybe a clean uninstall/reinstall of 2.9.52 or just skip it and move on to 3.x anyway.
That’s my ultimate goal anyway. I just thought getting there in baby steps would be less trouble prone, but I guess not. Would a full uninstall and clean install be a good idea?