¿How to manage (reset, clear, add) users to the chat global list users?

Hello

¿How to manage (reset, clear, add) users to the chat global list users?

I have a zextras chat on Ubuntu Server 12-Zimbra 8 (Zextras1.8.1) but the options “Add all the members of a Distribution List to each other's buddy list” in the chat administration zimlet is not funtional for all user, only is funtional for someone users. I need clear or reset all accounts chat list and use this options for add all user list to all chat users.

Thanks!!!