[Dovecot] deliver doesn't create home dirs

hello!

i'm trying to setup exim + dovecot's deliver for virtual users

in exim.conf: home_directory = "/var/mail/$domain/$local_part" command = /usr/lib/dovecot/deliver and in logs: No such file or directory: failed to chdir to /var/mail/symlink.ru/olfway

so why it doesn't tries to create that dir? maybe some switch can be added?

-- Pavel