What protocol is typically used for sending emails on the Internet?

Simple Mail Transfer Protocol (SMTP) is the standard protocol used for sending emails across the Internet. SMTP functions primarily in the sending and relaying of outgoing mail and ensures that your messages are transmitted to the correct mail server for delivery to the recipient's inbox.

SMTP operates by using a simple command structure and makes it easier for email clients and servers to communicate. When someone sends an email, their email client connects to the server using SMTP, which then handles the routing of the email to its destination. This makes SMTP a critical component in the infrastructure of email communication.

While other protocols mentioned also relate to email usage, they serve different purposes. For instance, Post Office Protocol (POP) is primarily used for retrieving emails from a mail server rather than sending them. In contrast, Hypertext Transfer Protocol (HTTP) is used for transferring web pages, and File Transfer Protocol (FTP) is utilized for transferring files over the network. Thus, SMTP remains the definitive answer for sending emails on the Internet.