Q. I have noticed in emails that people who want to be informal begin with “Hi Fred.” I have also seen the salutation as “Hi, Fred.” Since email is an electronic letter, is it OK to simply begin with “Hi Fred,”? The other way seems a bit awkward.

A. This isn’t so much a matter of Chicago style as personal style. Is it OK to treat email as an informal form of communication with relaxed rules and etiquette? It’s probably wise to use the same judgment you use in writing paper letters to people. If you’re writing to a client or your boss, follow the conventions of letter writing. In this case, that means putting a comma before the direct address (Hi, Fred). “Dear Fred” is not the same grammatically, and it takes no comma. (Note also that “Hi, Fred” and “Dear Fred” are not formal forms of address, with or without the comma.)