You can create distribution lists and assign owners to the list. The owners can manage the list from their accounts.
Distribution lists are stored in the Distribution Lists address book in the ZWC account.
Additional options that users can configure when they manage a distribution list from their account include:
Marking the list as private so it hidden in the Global Address List
Limiting who can send to the list to members only, to internal users, or to a specific list of users
Letting users subscribe to and unsubscribe from the list
Adding additional owners to help manage the list