[Dovecot] Sent, Drafts, Trash folders

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.

Thank you for any help.

Jason