Which protocol is primarily used for sending emails?

The protocol primarily used for sending emails is Simple Mail Transfer Protocol (SMTP). SMTP is responsible for the transfer of email messages from the sender's mail server to the recipient's mail server. When you send an email, your email client communicates with the server using SMTP to relay the email to the recipient's mail server.

SMTP is specifically designed for this purpose, facilitating the sending of emails through a reliable connection. It specifies how email messages should be formatted and transmitted, ensuring that emails reach their intended destination.

In contrast, other protocols listed serve different functions. FTP (File Transfer Protocol) is used for transferring files between systems, IMAP (Internet Message Access Protocol) is utilized for retrieving and managing emails from a mail server, and HTTP (Hypertext Transfer Protocol) is mainly used for accessing web pages. Each of these protocols has its specific role in internet communication, but SMTP is the go-to protocol for the sending of emails.