(D) An E-mail address consists of two parts. The part before the @ symbol (local-part)identifies the name of a mailbox. This is often the username of the recipient, e.g.,jsmith. The part after the @symbol (domain) is a domain name that represents the administrative realm for the mailbox, e.g., a company’s domain name, example.com.An email address identifies an email box to which email messages are delivered. A wide variety of formats were used in early email systems, but only a single format is used today,following the standards developed for Internet mail systems since the 1980 s.