OT: Dovecot+OE+mbox+subfolders

[Mike McMullen]

Hi All,

I have a dovecot IMAP installation that uses mbox because of a migration
from UW-IMAP about a year ago. I now have users requesting the ability
to create subfolders on the dovecot server. 

In OE when they go to do this on the dovecot imap server, the "New Folder" popup 
has the OK option greyed out. So they can't create the subfolder. Is this a limitation
of OE or the mbox format in dovecot? OE is the default mail client they use.

If it is in the mbox format and I try to convert to maildir, are there tools to migrate
mbox format folders to maildir? and how do we migrate the procmail recipes we
have? Is it possible to train spamassassin from maildir format?

TIA,

Mike