I would recommend Ladies and Gentlemen.
the Plural form of Madam is "Mesdames"
There are two accepted plurals for the noun madam: madams or mesdames.
It can be madames, madams OR mesdames, actually.
The plural of shoelace my dear is shoelaces.
In French, the plural of madame ("mah-dahm") is mesdames ("may-dahm"). As for English, I have never seen Madam used in the plural, but my dictionary says it used to be used with the spelling and pronunciation borrowed directly from French.
"Write" is a verb and therefore is the same applied to singular and plural, for example:"I write the music." and "They write the music."
Write-offs is the plural of write-off
A. Dear Dr. Smith, M.D.:
The plural form of nephew is nephews.
"Dear Sir or Madam"
The plural form for the noun rivalry is rivalries.
The plural form of the noun porch is porches.The plural possessive form is porches'.