Which of the following provides evidence of receipt of an important document sent through the post?

Recorded delivery service provides evidence of receipt of an important document sent through the post. This is because recorded delivery is a service offered by postal services where the sender can track the delivery progress of a package and receive a signature upon delivery as proof of receipt. The recipient of the package signs a form upon delivery and the sender can then obtain this form as evidence that the package was delivered. This provides assurance to the sender that the package has been successfully delivered to the recipient, which is particularly important for important or sensitive documents.