IMAP connection to specific directory

Hi, I am attempting to set up a group webmail client wherein certain emails can be stored separately from the normal mailbox system and retrieved for viewing by any user via a separate mechanism to the normal client. According to the documentation, I should be able to connect to this store using something of the form: imap_open("{localhost/imap}/path/to/maildir", "u", "p"); or perhaps: imap_open("{localhost/imap}#driver.maildir/path/to/maildir", "u", "p"); Various combinations of path, permissions, and so on all, without fail, yield the error "Mailbox does not exist, or must be subscribed to." Attempting to subscribe to the mailbox does not fix this, and since one of the paths tried was that of a mailbox accessible through the normal route: imap_open("{localhost/imap}INBOX", "u", "p"); ....I can only assume that I'm doing something wrong. Can anyone assist? Specifically, I need to know: * Are there any pitfalls associated with setting the mailbox up? (eg. path restrictions, permissions, ownership, format.) We're using maildir format elsewhere, it seems to be the most suitable. * How exactly should the imap_open command be written to access such a mailbox? Are there other commands needed as well (eg. imap_subscribe)? Thanks in advance, Niall