Which protocol provides e-mail facility?

🧠 Explanation:

SMTP stands for Simple Mail Transfer Protocol. It is the standard protocol used to send emails over the internet. The keyword “protocol” refers to a set of rules that govern communication between devices in a network. In this context, SMTP is a technical term and functions as a proper noun in computing because it represents a specific standardized name. SMTP works by transferring messages from the sender’s email client to the email server and then from one server to another until the message reaches the recipient’s server. Alternative protocols in the email system include POP3 (Post Office Protocol version 3) and IMAP (Internet Message Access Protocol), but these are mainly used for receiving emails, not sending them. Therefore, SMTP is the correct answer when the question focuses on providing the email facility for sending messages.