[Zope] Prohibiting Spams on the List

Hello ! Fristly excuse me for cross-posting. Actually, I did not like to be the person who comes this up however the amount of spams which is propagated thru the lists is annoying. I wonder why the guys at Zope Inc. does not tweak the list settings so posting is only allowed by the members. I have some experience with MailMan and I know it can be done by changing the following options: AdminIface-> Privacy Options -> Sender Filters -> default_memeber_moderation AdminIface -> Privacy Options -> Sender Filters -> generic_nonmemberaction I hope if there are other open-spam zope/plone lists, their managers see my message. :-) Thanks, Mohsen,