To my consternation, I have noticed that many people and advertising companies, perhaps the majority, omit a comma when a person’s or team’s name is in the sentence. I’ll add an X where commas belong in the sentences below. Pay particular attention to sentences that directly address a person.
Good for youX Henry!
NoX Sam, you are wrong about who started the argument.
Good morningX everyone.
In the last example, if you use the comma you are springing a surprise on Marlena. Without the comma, you are ordering someone to surprise Marlena as opposed to surprising someone else.