Mr. Mayor
Salutations are gestures or greetings that are meant as an acknowledgment. The proper salutation for a current mayor is Mr. Mayor or Madam Mayor.
"Your Honor" or "Mr. (Mrs.) Mayor"
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.
The proper salutation for a Mayor and her husband would typically be "Mayor [Last Name] and Mr. [Husband's Last Name]." If the husband holds a title or position, it may also be appropriate to acknowledge that title. In written communications, you might start with "Dear Mayor [Last Name] and Mr. [Husband's Last Name]." Always consider the preferences of the individuals when addressing them.
madame mayor
The mayor is generally referred to as Sir, or Mister Mayor. His wife, unless she holds a political office herself, is called Mrs. Whatever-her-last-name-is. - wjs1632 -
Mr. John Jones.
The proper salutation for a councilman is typically "Dear Councilman [Last Name]" when addressing them in writing. If the councilman holds a higher title, such as "Mayor," you would use "Dear Mayor [Last Name]." In a formal setting, it is appropriate to refer to them as "Councilman [Last Name]" or simply "Councilmember [Last Name]" if preferred. Always check for any specific preferences they may have regarding their title.
The proper salutation for a probate judge is "The Honorable [Judge's Full Name]."
What is the proper salutation for a register of wills, e.g. Honorable John White?
The proper salutation when writing to a judge is "Dear Judge [Last Name]" or "Your Honor."