The block letter is a format with all elements aligned with the left margin.
Some books also use the personal format with the address below the name.
Key the inside address four lines below the date line. Use double spacing between the inside address and the salutation. Key the subject line, if used, two lines below the salutation and two lines above the first message line. Position the optional attention line two lines below the last line of the inside address and two lines above the salutation. Single space the paragraphs, and use double spacing to separate them from each other.