The term 'SENDS IN A STAMPED ENVELOPE' refers to the process of sending a letter or package through the mail. This involves placing the item in an envelope, affixing the appropriate postage, and then sending it through the postal service. This is a common way to send items such as letters, cards, and packages. It is a reliable and cost-effective way to send items, and is often used for important documents or items that need to be sent quickly.