Comparison and Analysis of IMAP protocol and POP Protocol (1)

In terms of email, POP and IMAP are the most famous protocols. I don't need to talk about the POP protocol. Many users will be familiar with this protocol when setting some mailbox binding functions. Some friends may not understand the IMAP protocol. Here we will make a comparison between the two Protocols.

POP Protocol

POP stands for Post Office Protocol, which is the Post Office Protocol used for email reception. It uses TCP port 110 and is now commonly used in the third edition. Therefore, it is referred to as POP3. POP3 still adopts the Client/Server working mode ,. When the client needs services, the client's software OutlookExpress or FoxMail will establish a TCP connection with the POP3 server. After that, it will go through three working states of the POP3 protocol, first of all, the authentication process, confirm the user name and password provided by the client. After the authentication is passed, the user enters the processing status. In this status, the user can receive his/her own email or delete the email, after the response is completed, the client issues the quit command, and then enters the update status. The deleted emails marked with the deletion are deleted from the server. So far, the whole POP process has been completed.

IMAP protocol

IMAP is short for Internet Message Access Protocol. As its name suggests, it mainly provides a Protocol for retrieving information through the Internet. IMAP provides a convenient email download service like POP, allowing users to read offline, but IMAP can do more than that. The abstract browsing function provided by IMAP allows you to determine whether to download after reading the arrival time, topic, sender, size, and other information of all emails.

IMAP (Internet Message Access Potocol) is a protocol used for mailbox Access. The IMAP protocol can be used to manage the mailbox on the Server on the Client, which is different from pop, emails are retained on the server rather than downloaded locally. IMAP is similar to Webmail in this regard. But IMAP is better than Webmail. It is more efficient and secure than webmail, and can be read offline. If you want to try it, use Outlook Express. You only need to configure an account, set my email receiving server to an IMAP server.

IMAP (Internet Message Access Protocol) is another protocol that corresponds to POP3. It is a multi-Mailbox email system developed by Stanford University in 1986. It can obtain information about E-mail from the mail server or receive emails directly, with high performance and scalability. IMAP is adopted by many client email software, such as OutlookExpress and NetscapeMessenger. More and more software are supported on IMAP servers, such as CriticalPath, Eudora, iPlanet, and Sendmail.

Readers can't help but ask, POP3 is also an email receiving protocol. It is not very useful now. Why should I use the IMAP protocol?

POP3 protocol Insufficiency

Indeed, POP is the first offline protocol standard for Internet mail. It allows users to download emails from the server to a local host and delete emails stored on the email server, in this way, you do not have to connect to the email server for a long time, which greatly reduces the overall overhead of the server and network.

However, POP3 has its inherent defect: when a user receives an email, all emails are cleared from the server and downloaded to the client. During the entire email receiving process, the user cannot know the specific information of the email. The mail can be viewed and deleted slowly only after the full revenue of the hard disk is received. This makes it almost impossible for users to control the right to receive emails. Once an email address is bombed or a large number of emails exist, you cannot analyze the content of the email and the sender's address to determine whether to download or delete the email, resulting in a waste of system resources. The IMAP protocol not only overcomes POP3 defects, but also provides more powerful functions.

Second, IMAP Analysis

Analysis of IMAP

IMAP provides three operation modes

Online mode: emails are retained on the Mail server, which can be managed by the client. Its usage is similar to WebMail.

Offline: emails are retained on the Mail server, which can be managed by the client. This is the same as the POP protocol.

Separation Method: Part of the Mail is on the Mail server and part is on the client. This is similar to some mature component package applications such as Lotus Notes/Domino.

IMAP working principle and features

In the online mode, IMAP allows users to access and manipulate information on the mail server like accessing and manipulating local information. The IMAP software allows you to drag emails between local folders and server folders to store files on the local hard disk on the server or retrieve files from the server, all functions can be implemented only by dragging and dropping the mouse once.

You can create folders of any hierarchy on the mailbox on the server on the client, and flexibly move emails between folders to mark emails that have been read or replied, delete unnecessary files.