POP3, SMTP, and IMAP basic concepts

POP3

POP3 is the post Office Protocol 3 abbreviation, the 3rd version of the Post Office Protocol, which provides a way to connect personal computers to the Internet's mail server 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 a server on a local host (that is, their own computer) while deleting messages that are saved on the mail server, and the POP3 server follows the POP3 protocol's receiving mail server to receive e-mail.

SMTP The full name of SMTP is "Simple Mail Transfer Protocol", which is simply a message transfer protocol. It is a set of specifications for transmitting messages from the source address to the destination to control how the message is relayed. The SMTP protocol belongs to the TCP/IP protocol cluster, which helps each computer find the next destination when sending or relaying letters. The SMTP server is the outgoing mail server that follows the SMTP protocol.
SMTP authentication, simply by requiring that you have an account name and password before you can log on to the SMTP server, makes it easy for those spammers to do so.
The purpose of increasing SMTP authentication is to protect users from spam.

IMAP The IMAP full name is the Internet Mail Access Protocol, the interactive Mail Access Protocol, which is one of the standard protocols for similar mail access to POP3. On the other hand, when you turn on IMAP, the messages you receive from 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, and so on, and the message on the server will act accordingly. So whether you log in to the mailbox from the browser or the client software login mailbox, see the message and the status is consistent.

NetEase 163 Free Mailbox related server information:

What's the difference between IMAP and POP3?

The POP3 protocol allows e-mail clients to download messages on the server. However, actions on the client, such as moving messages, marking read, and so on, are not fed back to the server, such as collecting 3 of messages from the mailbox and moving to other folders on the client, which are not moved at the same time on the mailbox server.
And the IMAP provides the two-way communication between the webmail and the email client, the client's operation will be fed back to the server, the operation of the Mail, the Mail on the server will do the corresponding action.
At the same time, IMAP, like POP3, provides a convenient mail download service that allows users to read offline. The summary browsing feature provided by IMAP allows you to decide whether to download or not when you have read all the message arrival time, subject, sender, size, etc. In addition, IMAP better supports access to new messages from multiple different devices at any time.