Salutations are gestures or greetings that are meant as an acknowledgment. The proper salutation for a current mayor is Mr. Mayor or Madam Mayor.
Mr. Mayor
madame mayor
"Your Honor" or "Mr. (Mrs.) Mayor"
Mr. John Jones.
Dear Mr. Mayor or sometimes, such as New York, Your Honor.
'Dear Mayor Smith' is acceptable for ordinary communication. 'Your Honor' is a more formal salutation. In Canada (and, I think, in Britain also) it might be better to use 'Your Worship.' (A mayor historically had the powers of a magistrate.) Check with the municipality's office of protocol when in doubt.
Hugh Hallman is the current mayor of Tempe, AZ.
The current mayor of Absecon is Mayor Elco.
Beth Van Duyne is the current mayor of Irving, TX.
The first mayor of Warrnambool is John Grieve. The current mayor of Warrnambool is Michael Neoh.
Norm Archibald is the current mayor of Abilene, TX.
A. George Pradel is the current mayor of Naperville, IL.