Added missing weight emails

README.md

@@ -161,6 +161,26 @@ npm run build
 npm run worker
 ```
 
+### Overdue weight emails
+
+The worker checks every five minutes for living birds with no new weight entry in
+48 hours. Each accepted owner, assistant, or caregiver receives one email per flock
+listing all birds due for a reminder. Pending invitees and viewers are excluded.
+Reminders repeat every 48 hours while overdue; adding a new weight restarts the
+48-hour clock. Birds without weights use their profile creation time.
+
+The clock uses the weight entry's creation timestamp, since the measurement date
+has no time of day. Editing an existing entry does not restart the clock; entering
+a historical weight does. Memorialized birds are excluded.
+
+`WEIGHT_REMINDERS_ENABLED` defaults to `true` in both Compose stacks. Set it to
+`false` to disable delivery. The worker, Redis, Postgres, and existing SMTP settings
+must be available. The schema initializer creates the delivery tracking table.
+Missing SMTP configuration or failed sends leave reminders eligible for retry.
+Delivery tracking prevents ordinary repeat sends and concurrent claims; as with
+other SMTP delivery, a crash after acceptance but before saving delivery can cause
+a duplicate on retry.
+
 ## Auth and flock notes
 
 - One user can belong to multiple flocks.