Simple Mail Transfer Protocol (SMTP) is the standard protocol for sending emails across the internet.
SMTP is a text-based protocol that defines the rules for the interaction between the email client (sender) and the email server, as well as the interaction between different email servers.
SMTP works in conjunction with other email protocols, such as POP (Post Office Protocol) and IMAP (Internet Message Access Protocol), which are responsible for email retrieval by clients.
Together, these protocols ensure the complete cycle of email communication, from composing and sending to receiving and storing messages.