Q. I work for a company that says they’re focused on building client relationships. However, they insist when we address an email to one of our own clients whom we know well that we put a comma in hi, hello, or good morning, Joe. I have been told that this is a very formal way of addressing someone. Help!

A. The comma in a greeting of direct address is not very formal; it’s been the standard form for a very long time in all kinds of correspondence. Omitting the comma, on the other hand, is casual, and you never know which readers (especially anyone over forty) might consider it an error. Of course everyone understands that email is not a formal means of communication, but depending on the kind of business you are in, you might want your email to reflect a certain level of professionalism. If so, the comma is a good idea.