A BCC rule: messages whose sender (kind: :sender) or one of whose recipients (kind: :recipient) matches pattern (a full address, or @domain) are also sent to address.
kind: :sender
kind: :recipient
pattern
@domain
address
@type t() :: %Sovite.Core.Repo.Schemas.BccRule{ __meta__: term(), address: term(), id: term(), inserted_at: term(), kind: term(), pattern: term(), updated_at: term() }