i'm not sure but this might just be a config issue. could you enable imap_debug in the rc config please and then post the log? i wonder if you just need to set the namespace in your rc config
about outlook express, i dont know i havent used that. i know outlook can be set to use imap folders for Sent etc rather than local ones, i guess outlook express has similar options but you'd have to check in outlook express's help files.