Email transfer protocols have evolved through industry consensus and academic research since the 1970s. Simple Mail Transfer Protocol (SMTP) is primarily used as a protocol for sending data. Internet Message Access Protocol (IMAP) and Post Office Protocol (POP3) are for receiving data. These connection standards are used to configure email clients on the desktop. The difference between IMAP and POP3 is related to storing messages. POP3 deletes the original message from the server after downloading, while IMAP syncs it across multiple devices. Which one to use depends on the client connections of the email software platform.