What is the main content or message part of a letter referred to as?

The main content or message part of a letter is referred to as the body. This section contains the detailed information or communication the writer wishes to convey to the recipient. It includes the primary topics of discussion, thoughts, or requests and is structured in paragraphs that provide clarity and flow to the message.

The header typically includes the sender's address, date, and possibly the recipient's address, which provides context but does not contain the main message. The salutation is the greeting at the beginning of the letter, such as "Dear [Name]," and serves to address the recipient. The closing is the farewell or sign-off at the end of the letter, such as "Sincerely" or "Best regards," wrapping up the communication but also not conveying the letter's main content. Thus, the body is distinctly identified as the section that holds the primary message.