Comment 8 for bug 56235

On my system, when the script is like yours, I get the following error message:

$ sudo /etc/init.d/postfix stop
 * Stopping Postfix Mail Transport Agent postfix
postfix/postfix-script: fatal: usage: postfix start (or stop, reload, abort, flush, check, set-permissions, upgrade-configuration)

Similarly for "/etc/init.d/postfix start"

I think this error message is indeed correct, since /usr/sbin/postfix (the value of the variable DAEMON)
does require a command like "stop" or "start". I don't understand how the script can call it like it does
and not generate an error.

Perhaps you could try to run the /usr/sbin/postfix program directly, like this:
$ sudo /usr/sbin/postfix -- quiet-quick-start

On my system this generates an error:

postfix/postfix-script: fatal: usage: postfix start (or stop, reload, abort, flush, check, set-permissions, upgrade-configuration)

Similarly for stop:

$ sudo /usr/sbin/postfix quiet-stop
postfix/postfix-script: fatal: usage: postfix start (or stop, reload, abort, flush, check, set-permissions, upgrade-configuration)