Change "from"-address for cron emails

Is there a way to change the "from"-address for cron emails?
I get messages from "root@subdomain.domain.com", but I want from address to be "root@domain.com".
My full FQDN is "subdomain.domain.com" (also the URI where the plesk panel is accessible) which is also my /etc/hostname and /etc/mailname.
Mail server is reachable from "mail.domain.com".

Is there a way to tell cron or postfix to use "root@domain.com" as sender address for cron / system...

Change "from"-address for cron emails