What are POP3, SMTP, and IMAP?

POP3

POP3It is short for Post Office Protocol 3, which is the 3rd version of the Post Office Protocol. It specifies how to connect a personal computer to an Internet Mail Server and download an email protocol. It is the first offline protocol standard for Internet email,POP3 allows you to store mails on the server to a local host (that is, your computer) and delete the mails stored on the mail server.The POP3 server follows the POP3 protocol and is used to receive emails.

 

SMTP

SMTPThe full name is "Simple Mail Transfer Protocol", that is, Simple Mail transmission protocol. It is a set of specifications used to transmit mails from the source address to the destination address. It is used to control the transfer mode of mails. The SMTP protocol is a TCP/IP protocol cluster that helps each computer locate the next destination when sending or transferring letters. The SMTP server is the mail sending server that follows the SMTP protocol.
SMTP authentication simply requires that you have to provide the account name and password before you can log on to the SMTP server, which makes the spam recipients have no chance.
SMTP authentication is added to prevent spam attacks.

 

IMAP

IMAPInternet mail access protocol (Interactive mail Access Protocol) is one of the standard mail access protocols similar to POP3. The difference is that after IMAP is enabled, the emails you receive on the email client are still retained on the server, and the operations on the client are reported to the server, such as deleting emails, mark as read, and the emails on the server will also take corresponding actions. Therefore, whether you log on to the mailbox from the browser or the client software, the emails and status are consistent.