* Allow multiple Customers to use the same email, as long as they are linked to distinct Mailboxes.
* Display all Customers when using an admin account. * Add the ability to set the Mailbox when editing a Customer. * When editing a Customer, pre-select its current Mailbox.
* Improve the initial linking of Customers to Mailboxes, to include Customers linked with several Conversations.
* On the initial package install, link existing Customers to Mailboxes
