>кто mail_owner ?
>mail_owner = postfix
гонит беса mail_owner демон local(8), но почему?
DELIVERY RIGHTS
Deliveries to external files and external commands are
made with the rights of the receiving user on whose behalf
the delivery is made. In the absence of a user context,
the local(8) daemon uses the owner rights of the :include:
file or alias database. When those files are owned by the
superuser, delivery is made with the rights specified with
the default_privs configuration parameter.
Должны быть взяты права receiving user из alias database но не тут то было,
наверно local(8) хочет записать с правами nobody?