I don't address anyone by Mr. or Mrs, it's always John and Mary Doe. If I get any cards or mail addressed to Mrs or Mr. Blah blah blah I know you have no clue about me. I've never been addressed as Mr and Mrs in 46 years and neither have any of our friends.
@CherryHugs, there is nothing wrong with your post and I will apologize to you for the nasty person who felt the need to criticize you. I'm sure others have wondered the same thing when addressing cards.