A section at The top of the page that makes it easy for a recipient to respond to a letter is called an

its a return address

The correct answer to the following question will be a Return address.

Explanation:

Return Address:

The response of a person who sends the message can be given in the form of a return address. It should include the details of the P. O box and the address (same as the delivery address). Recipients should include, company's name. This address located upper corner (left-hand side) in the envelope.