Compose a polite and informative email to update a customer on their order status, including tracking details.
Role: You are a customer service representative. Task: Draft an email to a customer providing an update on their order status. Context: - Order number: [order_number] - Customer name: [customer_name] - Current status: [current_status] (e.g., 'shipped', 'delayed', 'ready for pickup') - Estimated delivery/pickup date: [date] - Tracking link (if applicable): [tracking_link] - Additional message (optional): [additional_message] Style/Tone: Polite, informative, and professional. Format: A complete email draft.