List permissions in CBMailing
CBMailing controls who can send mail by a system of list permissions. Basically, you can assign members of one list the right to send mail to the members of another list. We set up sites so that the "Super administators" list can mail to any list - and no other list has any mailing rights.
If you create a new list in the Community Builder List Manager, and you want to send mail to it. Then you will need to use CBMailing to give the "Super Administrators" the right to mail to your new list. To do so, go to Joomla->Components->CBMailing->Manage permissions.
Under "New permissions" select "Super administrators" in the list permitted to send from box, and your new list in the list permitted to send to box, then click the "Save" icon in the top right. Once you have done this you should be able to send mail to your new list.