unable to edit wiki 2, here's the edit:

19 Dec 2019


      In https://wiki.dovecot.org/Migration/Courier ,
mail_location = maildir:~/Maildir
namespace {
prefix = INBOX.
separator = .
inbox = yes
}
... is wrong.  Apparently it should be ...
mail_location = maildir:~/INBOX
...which at least seemed to work, although (by that time?) I wound up re-downloading all mail.
Steve Newcomb
srn@coolheads.com
(Unable to edit the wiki page...  Mysterious question stood in the way, something like, "How do you prevent spam?"  Evidently I don't know the correct answer.