If I run the following command I get this message:
$ zmzimletctl acl com_zimbra_asterisk.zip standardusers deny
INFO: Removing Zimlet com_zimbra_asterisk.zip from COS standardusers
Then I restarted zimbra completly.
Seems to work but when you actualy test they have access to the Asterisk Zimlet. This is a srever that we offer some VOIP services to clients that pay for it and others do not. I do not want them to have acess.