That part of the letter is called the salutation or greeting.
salutation
"Dear Seth" would be the greeting.
Dear Mr. President is a salutation of a business letter. The salutation goes at the beginning, thus that's how you got Dear.
greeting
greeting
The body of the letter is the part between 'Dear...' and 'Sincerely,'.
That part is known as the SALUTATION or GREETING.
An example of a greeting of a letter, also known as the salutation, is "Dear Sir,"
The opening of a letter is called a salutation. It typically includes a greeting, such as "Dear [Name]," followed by a comma.
Example:Letter Dear ______, ____________________________________ ________________________________________ ________________________________________ ________________________________________ Sincerely, ________ (P.S. __________________________________) Note: The P.S. part is optional
greeting