An email server is a computer system that manages the sending, receiving, and storage of email messages. It acts as a digital post office, ensuring that emails are delivered to the correct recipients. Email servers use specific protocols, such as SMTP (Simple Mail Transfer Protocol) for sending messages and IMAP (Internet Message Access Protocol) or POP3 (Post Office Protocol) for retrieving them. These servers can be hosted on-site by organizations or provided by third-party services like Google Workspace or Microsoft 365. They play a crucial role in communication, allowing users to send and receive messages across the internet efficiently and securely.