I've finally install courier-imap 1.4.2 and got it working!
Anyway, I'm testing mail folder management via Outlook Express, and found
that I can only create mail folders under Inbox. I would like to create mail
folders that are on the same level as Inbox in the tree hierarchy (hope you
know what I mean). When I tried to create a mail folder outside of the
Inbox, the request failed with the response 'Invalid mailbox name'.
I'd appreciate any suggestions.
I don't believe you can with OE. It likes to keep the folders as a
hierarchy under INBOX.
Incorrect. OE are capable to show personal folders at the same level as
INBOX. Just enter the correct folder path ("INBOX." for a unmodified
courier-imap server) under the IMAP tab in the mail account's preferences.