First of all, a formal email should be complete. Always put a subject in the subject line, and try to make it as specific as possible, so the other person knows the purpose of your email. Writing Information isn’t enough, but Information about your interview process is. There should always be a greeting in formal e-mails, such as those to teachers. When students don’t use an instructor’s formal name, they could offend the instructor. Dear Prof. Winters is better than Teacher or nothing at all.