As a user I want to be able to create recipient lists. When sending a mail or calendar invites I want to be able to use such a list in the address field to send the mail to every user in the list without entering each mail address individually. Furthermore, I want to be able to share such lists with other users and define who has which right on the list (read/write/manage). I want to be able to share multiple lists at once with the same group while also being able to share different lists with different users. For privacy reasons I only want to share the mail address (and optionally a name) for each entry in the recipient list but not the entire contact I have in my private contact list. I do not want to share entire contact lists. In the contact view I want to be able to see and edit all my recipient lists and who they are shared with.