[Dovecot] LOCK FILE

[Alex]

i'm working with exim 4.60, with mbox,  and dovecot dovecot-1.0.beta7,
and filesystem quotas

default_mail_env = mbox:~/mail::INBOX=%h/mbox:INDEX=/tmp/%u

lock_method = dotlock fcntl
mbox_read_locks = dotlock fcntl
mbox_write_locks = dotlock fcntl


The home of users is
/home/usuaris/user


Where place dovecot the lock file?