"Dear Mr. (Mrs.) Roberts" or "My dear Mr. (Mrs.) Roberts." The use of "My dear" is considered more formal than merely "Dear," except in England where the first form is considered the more intimate.
The form "Dear Miss" or "Dear Friend" may be used on no condition whatever. It is either "Dear Miss Wimberley" or "Dear Madam." It is considered presumptuous, in good society, for a man to address a lady as "Dear Mrs. Brown" until she has first dropped the formal "my" in her correspondence with him.
The strictly formal method for addressing a letter to a man by a woman who is a total stranger to him, is:
"Mr. John D. Brown,
"Dear Sir."
If he is a distant relative, addressed for the first time, or the friend of a very intimate friend, the salutation may read, "My dear Mr. Brown."
CLOSING THE LETTER
The endings "Very truly yours" or "Yours truly" express a certain formality. Friendly letters are closed with such expressions as, "Yours most sincerely," "Cordially yours," "Very affectionately yours," "Lovingly yours." The latter two expressions are confined largely to intimate friends and relatives, while the others are used when letters are written to new acquaintances or casual friends. The pronoun yours should never be omitted, as it leaves the phrase unfinished and is not complimentary to the person addressed. Thus, closings, such as "Very truly" or "Sincerely" are in bad form.
