I am trying to set up my old email as a maildir account. My old email is in a folder `oldmail/`, specifically in `oldmail/local-mail` and `oldmail/.local-mail.directory` (for the subfolders). In kmail I went to

Settings -> Configure KMail -> Accounts -> Receiving -> Add -> Custom Acccount -> Maildir

where I tried writing "oldmail/" or "oldmail/.local-mail.directory" or oldmail/local-mail" into "Select the folder containing the maildir information". In each case I might get a "database" symbol in the main window of KMail, but no email is displayed. Restarting akonadi did not change anything.

How do I set up my old mail?