My wife bought a "smart" air freshener and it required an app, which is fine I guess. But it also required her to "create an account" and that has been irritating me for days. I'm not doing either so I now have no control over how the house smells.
I finally figured out what was causing my Mu4e troubles. Disable "--allow-temp-files" by setting
(setq mu4e-mu-allow-temp-file nil). The new flag was added recently but I think my mu binary is too old. Mu4e works now, though.
I was feeling that my Emacs config was getting a little heavy, so I checked, and at (only?) 2,063 lines of Lisp, it's not that out of control, right?