Why is the body of the letter called as heart and soul of the letter?

The body of the letter is referred to as the "heart and soul" because it contains the main message and purpose of the communication. This section elaborates on the sender's thoughts, feelings, or information, making it the most critical part of the letter. Just as the heart and soul are essential to a person's being, the body of the letter conveys the core intent and significance of the correspondence. Without it, the letter would lack substance and meaning.