Final answer:
The subject line is the element of a letter used to attract the receiver's attention and prioritize the content, acting similarly to an essay title and ensuring that the content is immediately apparent.
Step-by-step explanation:
The element of a letter that is used to attract the receiver's attention and prioritize the content is the subject line. A good subject line acts like an essay title and should clearly represent the main point of your correspondence, ensuring that the content of the email will be immediately apparent to your reader. This helps the recipient to prioritize your letter among others they may receive and encourages them to respond in a timely manner. In a formal letter, the subject line comes after the salutation, which opens with a polite greeting using the person's title or honorific such as Mr., Ms., Mrs., or Dr. The body of the letter begins with a first paragraph that introduces the context of your message succinctly. For a business letter, following a specific format that includes the date, sender's address, recipient's address, salutation, body, and closing line is essential.