rc.sysinit is from the Red Hat family, so I'd wager your server is Red Hat or CentOS.
You need to give the root password when prompted (not Ctrl-D)...
What do the log files actually say, where you found that Postfix error?
You really don't want to allow root ssh logins at all, so it's good that you've disabled them. Changing the port ssh listens on is also a good move....
Linux for Business
Separate names with a comma.