“Salutations or greetings when starting an email, business letter, legal letter, cover letter, or professional letter can set the tone for the message. It informs the reader that the message is either going to be formal and professional (or serious). Or informal.

If you choose the wrong salutation, it might be sending mixed signals to the reader. For example, if your letter is intended to be serious but you use an informal greeting, you might expect to get an informal response. Which may not have been your intention from the start.”