Which protocol is primarily used for email transfer?

The Simple Mail Transfer Protocol (SMTP) is primarily used for the transfer of email across the Internet. It is a protocol that defines the rules and procedures for sending and relaying email messages. SMTP operates at the application layer of the Internet Protocol Suite and is responsible for the delivery of emails from the sender’s mail server to the recipient’s mail server.

SMTP functions by establishing a connection between email servers and facilitates the sending of messages in a standardized way, ensuring that emails are correctly routed and delivered to the correct addresses. It uses a text-based command and response format for communication, making it effective for handling email transactions over the Internet.

Meanwhile, Internet Control Message Protocol (ICMP) is primarily used for network troubleshooting and managing errors, such as notifying hosts when packets cannot reach their destination. Transmission Control Protocol (TCP) is a foundational protocol that supports the reliable transmission of data over networks but is not specific to email communication. File Transfer Protocol (FTP) is designed for transferring files between systems and does not specifically address email transfer. Each of these protocols serves distinct purposes, which highlights the specialized function of SMTP in the realm of email communication.