NatureBox does not require a signature for your snacks at the time of delivery. It is up to the individual postal carrier's discretion whether or not to leave your package if you are not present at the time of delivery.
All US packages are shipped FedEx Smart Post, which means that FedEx transfers to USPS for final delivery. For Canada, we ship through Landmark Global who decides how to get your order the soonest. They work with several Canadian carriers with majority of the orders being ship through Canada Post.