[Dovecot] postfix deliver to mdbox ?

Hello again

I' now in trouble with incoming email's to users

I have modified the main.cf config file of postfix according to the Dovecot LDA with Postfix page.

mailbox_command = /usr/local/libexec/dovecot/dovecot-lda

postfix reload

But incoming emails does not seems to go in the mdbox INBOX

I use postfix 2.8.0 with FreeBSD 8.1

Any clarification welcome !

Thanks again.