postfix/dovecot some users can send mail to the distribution list and other users not

Hello!
i would like to set: only the admin users can send mail to the [email protected] distribution list, the others noit. How can i set to the postfix?
i found this howtos http://www.postfix.org/RESTRICTION_CLASS_README.html ,but this isnt.

my postfix ver: 2.11.0
Thanks for help.