Simple Mail Transfer Protocol (SMTP)

SMTP is the Simple Mail Transfer Protocol. The SMTP protocol is a transmission protocol in the IP network that transmits e-mails. The IMAP and POP3 protocols retrieve and manage mails. The SMTP protocol, on the other hand, can only be used to send mails. In the beginning, the SMTP protocol only understood ASCII characters. However, since the MIME (Multipurpose Internet Mail Extensions) standard was introduced, the protocol can process and use binary files. The Simple Mail Transfer Protocol is a client-server protocol. The client is responsible for establishing a connection to the server and sending the commands. The server then executes the commands and informs the client of the result.