What is the proper salutation for a former Governor of a state?

Answer 1

http://www.formsofaddress.info/former.html#FO011

How to Address a Former Governor?
Dear Mr. Hickey:
What is the proper form of address when writing a letter to a former Governor? When he calls, he says "This is Governor (surname)" even though he is no longer the Governor. I have made it "The Honorable (full name)" in the letter's address block, and "Dear Governor (surname)" in the salutation. Sound right?
--- Lonnie Sue Reardon

Dear Ms. Reardon:
His name in the letter's address block is easy. A former governor is The Honorable (full name).
But ... the saluation (in this case) is a two part answer
PART #1 Only a Governor in office is formally and officially addressed as Governor (name). The correct salutation for a former governor is Dear Mr./Ms./Dr./etc. (name): The reason? There is only one Governor at at time!
PART #2 However, if you know it's his preference to be addressed as Governor (name) follow "the preference of the bearer." It doesn't make it correct for others, but I'd honor any person's preference what they are called.
For example, if we met and you introduce yourself as Monsignor Lonnie Sue I would think "a monsignor is Catholic priest and always man." SO its "unlikely" you are a monsignor. But I'd call you Monsignor Lonnie Sue to your face: It's not up to me to decide what your name is.
However I wouldn't think you'd changed what was correct for others.
-- Robert Hickey