What are the differences and connections between POP3, SMTP, and IMAP?

POP3 is to download the message to the local computer. IMAP is a direct operation that connects remote mailboxes. Two are all received, SMTP is a letter.

SMTP the full name is "Simplemail Transfer Protocol" , which is the Simple Mail Transfer protocol. It is a set of specifications for transferring messages from the source address to the destination, which controls how messages are relayed. the SMTP Protocol is a TCP/IP protocol cluster that helps each computer find its next destination when sending or relaying letters. the SMTP server is The outgoing mail server that follows the SMTP protocol.

IMAP Full name is internetmail Access Protocol , which is the interactive Mail Access Protocol, which is POP3 similar to one of the standard protocols for mail access. The difference is that when IMAP is turned on , the messages you receive on the email client remain on the server, and the actions on the client are fed back to the server, such as deleting the message, marking the read, etc. Messages on the server will also act accordingly. So whether you log in to the mailbox from the browser or the client software, you see the message and the status are consistent.

POP3 is the abbreviation for Post Office Protocol3 , the 3rd version of the Post Office Protocol, which specifies how to connect personal computers to the Internet's mail servers and electronic protocols for downloading e-mail. It is the first offline protocol standard for Internet e-mail, POP3 allows users to store messages from the server on a local host (that is, their own computer) while deleting messages saved on the mail server, while the POP3 server is the receiving mail server that follows the POP3 protocol to receive e-mail.

What is the difference from IMAP ?

POP3 The protocol allows e-mail clients to download messages on the server, but actions on the client, such as moving messages, marking read, and so on, do not feed back to the server, for example, by charging 3 of messages in the mailbox and moving them to other folders. These messages on the mailbox server are not being moved at the same time.

while IMAP provides two-way communication between the webmail and the email client, the client's actions are fed back to the server, the messages are manipulated, and the messages on the server do the corresponding actions.

at the same time, IMAP , like POP3, provides a convenient e-mail download service that allows users to read offline. IMAP The Summary browsing feature allows you to decide whether or not to download after you have read all the message arrival time, subject, sender, size, etc. . In addition, IMAP is better able to support access to new messages from multiple different devices at any time.

in short, IMAP provide users with a more convenient and reliable experience on the whole. POP3 is more likely to lose mail or download the same message multiple times, but IMAP through the mail client and Webmail The bidirectional synchronization between the two features is a good way to avoid these problems.

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What are the differences and connections between POP3, SMTP, and IMAP?