You can't mix these two different types of abbreviations in your heading
What is POSTAL and STANDARD?
400
The two different punctuations found at the end of the salutation
What is a comma(,) in a friendly letter and a colon (:) in a business letter?
400
The first letter is capitalized
What is the first word of the closing?
500
It is not found under the heading in a friendly letter
What is the inside address?
500
The two types of abbreviations that can be used in the heading
What is POSTAL and STANDARD?
500
What is found in the four lines of the inside address
What is
1.the name of the person to whom the letter is written
2.the name of the company or organization
3. the street address
4. the city, state, and zip code