He full name on the letter is fine. If she is married you could add Signora in front, if she is single Signorina. Example: Signorina Maria Antonellli or just Maria Antonelli.
signora // Sig.ra abbreviated
A title or form of address used of or to an Italian-speaking unmarried woman, corresponding to Miss
There is a great deal of confusion as to how to address a letter to an assembly woman in office. The proper salutation would be Dear Honorable and then their name.
Frau
when writting a business letter to a woman with a hyfanated name do you use both names
The way to address an Italian gentleman begins with the word Signore ("Sir") in Italian.
The abbreviation in Italian for Mr. is "Sig." which stands for "Signore," and for Mrs. is "Sig.ra" which stands for "Signora." These abbreviations are commonly used in formal contexts in Italian language to address or refer to a man or a woman respectively.
Para a Sra... (Mistress) Para a Srta. (Miss)
"Strong woman" in English is virago in Italian.
"Single woman" in English is nubile in Italian.
"Lucky woman!" in English is Donna fortunata! in Italian.
a married Italian woman the answers in the question Signora or Madame. As in the English Mrs. or Madam.