How You Configure Mailboxes for Multiple Interfaces
If you have Service enabled, you must create at least one Service mailbox for the new interface in order to send and receive email. If Outreach or Feedback is enabled, you must create at least one Outreach mailbox to create and send mailings and surveys.
If you have multiple mailboxes for the interface, you must specify a default Service mailbox and a default Outreach mailbox. Even though you can configure your interface to send email from a single address, if you have multiple mailboxes, you must configure each mailbox separately. However, you can configure mailboxes for all interfaces, from any interface, using the Mailboxes editor. See How Mailboxes Work.
Distribution lists are not interface specific so any distribution list you add on one interface is available on all other interfaces. See Add or Edit a Distribution List.