Australia Post offers three services when you require fast delivery of letters and documents: 

1. Express Post  - when you require next business day delivery between Australian capital cities (except Darwin) and major centres, as well as to many country centres. Other areas in Australia receive a faster than standard service.   
2. Express Post Platinum - when you require the speed and convenience of Express Post but also require signature on delivery and on-line tracking within the Express Post Platinum network.
3. Messenger Post Couriers  - when you require a courier to deliver the same day in the metropolitan area with online booking and tracking. A signature is obtained for all deliveries and proof of delivery is available immediately upon request.