feat: add expected recipient reporting

config/mailbox.example.yml

@@ -15,12 +15,18 @@ scan:
   mode: incremental
   max_messages_per_run: 5000
   since: null
+  from: null
+  to: null
   include_seen: true
   mark_seen: false
   store_raw_headers: true
   store_raw_body: false
   store_raw_message_ref: true
 
+expected_recipients:
+  path: null
+  csv_column: email
+
 storage:
   path: .email-connect/state.sqlite