IMAP Mailbox Location Prefix

I’m trying to switch to IMAP using Eudora 6. From looking at the web it seems I should put in mail/ in the IMAP Mailbox Location Prefix.
I have tried, mail/, inbox, the name of the personaility all to no avail.
I keep getting a IMAP error. Please help.

Does INBOX. or INBOX work?

Sadly, Not. But putting INBOX. gave me the message fetching … before giving me the failed error, while INBOX just gave me that error instantly.

Thank you. That did help. My your path through life be smooth.

I had the box, Secure Sockets when receiving(default) set to If Available Start TTLS. I changed it to “never” as indicated. But what does this mean to the security of my email?

Here is what the error message was about:
A progress message pops up and says fetching list from server

And then I got the message “The IMAP command has failed”