On 20.8.2004, at 22:25, Jason M. Wilde wrote:

I am hosting imap mail for a new affiliate and am offering webmail via squirrelmail as well.  Squirrelmail created INBOX.Sent, INBOX.Trash, etc by default and I would like to use these folders for my Dovecot imap users.  I am using the mbox format, Postfix and users retrieve mail via the Outlook client remotely in addition to webmail access.

You should rather have removed the INBOX prefix from Squirrelmail configuration so it doesn't create them under INBOX. Alternatively you'll have to set INBOX prefix to all Outlook users settings.