Which protocol is primarily associated with sending emails?

SMTP, which stands for Simple Mail Transfer Protocol, is specifically designed for sending emails across the internet. This protocol enables the transfer of messages from the sender's email server to the recipient's email server and is widely used for the sending of messages in email communication. When an email is sent, it is transmitted through various servers using SMTP until it reaches its destination, where another protocol, often IMAP or POP3, is typically used to retrieve it.

In contrast to SMTP, IMAP (Internet Message Access Protocol) is used for retrieving and managing emails from a server, allowing users to access their messages from multiple devices. HTTP (Hypertext Transfer Protocol) is the foundation for transmitting web pages on the internet and is not related to email. FTP (File Transfer Protocol) is primarily used for transferring files between computers on a network, rather than for managing or sending emails. Understanding the role each of these protocols plays in communication networks helps clarify why SMTP is specifically associated with the email-sending process.