The format of a formal letter typically includes the following elements:

1. Senders address: This includes the name, address, and contact information of the person writing the letter. It is usually placed at the top of the letter, either on the left or right side.

2. Date: The date on which the letter is written is usually placed below the senders address.

3. Recipients address: This includes the name, address, and contact information of the person or organization to whom the letter is addressed. It is usually placed below the date, on the left side of the letter.

4. Salutation: This is the greeting that begins the letter, such as "Dear Mr./Ms./Dr. [Last Name]". It is usually followed by a colon.

5. Body paragraphs: This is the main content of the letter, where the writer expresses their purpose for writing and provides any necessary details or information. It is usually divided into several paragraphs.

6. Closing: This is the part of the letter where the writer concludes their message and expresses any final thoughts or requests. Common closings include "Sincerely", "Best regards", or "Yours truly".

7. Signature: The writers signature is usually placed below the closing, followed by their printed name.

It is important to maintain a professional tone and adhere to standard conventions in formatting a formal letter. Different organizations may have different format requirements for their professional communication, so it is important to check for any specific guidelines before writing a formal letter.