> To test for sending email after postfix installed.
> echo "test" | mail -s "test" [hidden email] > Mail Delivery Status Report will be mailed to <root>.
> The email was received in my gmail account.
> No mail for root
> root@localhost:~# mail -f /var/mail/root
> mail: /var/mail/root: No such file or directory
> root@localhost:~# mail -f /root/Maildir
> mail: /root/Maildir: Is a directory
Short answer: follow best practice, and alias mail for root to a
person (or persons, as the case may be).
Long answer: Postfix will not run any external commands (such as
procmail) as root.