When writing a letter to a two people (in my case husband a wife), how do you write the greeting??
Mr and Mrs. John Smith?
Mr. John and Sue Smith?
I'm not quite sure which is more formal and correct.
It depends upon how well you know them, and how you address them in person.
Dear Mr. and Mrs. Smith is the more formal salutation.
Dear John and Sue is used if you are friendly with these people and call them by their first names in person.