Email addresses always include which symbol?

Email addresses always include the at sign (@) as a fundamental part of their structure. This symbol is crucial because it separates the local part of the email address (which identifies a specific user) from the domain part (which identifies the server that hosts the email). For example, in the email address user@example.com, "user" is the local part, and "example.com" is the domain. The at sign ensures that the email system correctly routes messages to the intended recipient by clearly delineating these two components.

The other symbols listed do not have a role in the formation of standard email addresses. The ampersand (&), hash (#), and dollar sign ($) are not used in traditional email formatting and could potentially lead to errors if included incorrectly. Understanding the significance of the at sign enhances recognition of valid email formats and contributes to proper email communication.