Can't see IMAP folders in Apple Mail

Can't see IMAP folders in Apple Mail

Like many others, I'm finding the IMAP server very flaky. In addition, I can't see any of the IMAP folders in my Apple Mail program.

What setting should I have in the "IMAP Path Prefix" box? Some IMAP servers like it blank, some like a "/" character, and some like the word "INBOX". I've tried all of these, but can't get the folders to appear in Apple's Mail program.

Martin S Taylor