[Dovecot] Dovecot using static uid gid

Hi All

I have postfix deliver the mail in virtual maildirs using the UID of user dovecot. I authenticate users trying to access their mailboxes via IMAP through winbind. The authentication is successfull but dovecot logs imap(username): Date "Error: openidir (vmail/domain/username) failed: Permission denied.

I tried to insert in dovecot.conf: static uid=97 gid=97 home=/vmail/domain but I get a report that parameters are missing. Does anybody know the the exact syntax for the static directive?

Alexandru