What is e-mail?

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E-mail (e-mail for short, logo: @, also known as "Yi Meier"), also known as e-mail and e-mail, is a communication method that provides information exchange through e-mail. It is the most widely used service on the Internet: through the e-mail system of the network, users can get in touch with network users in any corner of the world in a very fast way (it can be sent to any destination you specify in the world in a few seconds), and the price is very low (no matter where it is sent, only the telephone and network fees need to be paid). These emails can be in many forms, such as text, images and sounds. At the same time, users can get a lot of free news and special emails to realize easy information search. This is unmatched by any traditional way. E-mail is widely used because of its simple use, rapid delivery, low cost, easy preservation and unimpeded global access, which has greatly changed people's communication methods. In addition, email can be sent in a one-to-many way, and the same email can be sent to many people at the same time. Most importantly, e-mail is a system that directly faces the information exchange between people in the whole Internet and all other network systems. Its data sender and receiver are both human beings, so it greatly meets the communication needs of a large number of people.

E-mail refers to the communication mode of transmitting letters, documents, materials and other information by electronic means. E-mail combines the characteristics of telephone communication and postal letters. It can transmit information as quickly as a telephone and make the receiver receive a written record like a letter at the receiving end. E-mail system is also called computer-based mail information system. It undertakes the whole processing process from the mail entering the system to the mail reaching the destination. E-mail can be transmitted not only through telephone network, but also through any communication network. When using the telephone network, you can also use it to transmit information during off-peak hours, which is of special value to commercial mail. An electronic system controlled by a central computer and a small computer for limited users can be regarded as a computer conference system.

Workflow of E-mail

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The working process of e-mail follows the client-server model. Every e-mail is sent with the sender and the recipient involved. The sender constitutes the client, and the receiver constitutes the server, which contains the email addresses of many users. The sender sends the edited e-mail to the post office server (SMTP server) through the mail client program. The post office server recognizes the address of the recipient and sends the mail to the mail server (POP3 server) that manages the address. The mail server stores the message in the recipient's e-mail box and notifies the recipient that a new mail has arrived. After the recipient connects to the server through the mail client program, he will see the notice sent by the server, and then open his e-mail box to check the mail.

Usually, individual users on the Internet can't directly receive e-mail, but apply for an e-mail address of an ISP host, and the ISP host is responsible for receiving e-mail. Once the user's e-mail arrives, the ISP host will move the e-mail to the user's e-mail box and notify the user of the new e-mail. Therefore, when sending an email to another customer, the email is first sent from the user's computer to the ISP host, then to the Internet, then to the recipient's ISP host, and finally to the recipient's personal computer.

The ISP host plays the role of "post office" and manages the e-mail boxes of many users. The e-mail address of each user is actually the account name applied by the user. Each user's e-mail account takes up a certain amount of hard disk space of ISP host. Because this space is limited, users should regularly check and read the emails in their email boxes to make room for receiving new emails.

Format of mail address

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On the Internet, the e-mail address is just like your own identity. Generally speaking, the format of e-mail address is as follows: 123@yojian.com or abc@yoxiang.com mailbox cannot be in Chinese.

Domain_name here is the identifier of the domain name, that is, the domain name of the mail destination to which the mail must be delivered. Someone is an email address on the domain name. Suffixes generally represent the nature of domain names and area codes. For example: com, edu.cn, gov, org and so on.

Domain names are technically mail exchanges, not machine names.

Common e-mail protocols are as follows: SMTP (Simple Mail Transfer Protocol), POP3 (post office protocol) and IMAP (Internet Mail Access Protocol). These protocols are defined by the TCP/IP protocol family.

SMTP (Simple Mail Transfer Protocol): SMTP is mainly responsible for how the underlying mail system transmits mail from one machine to another.

POP (post office protocol): The current version is POP3, which is a protocol for transmitting mail from an e-mail box to a local computer.

IMAP (Internet Mail Access Protocol): The current version is IMAP4, which is an alternative protocol to POP3. It provides new mail retrieval and mail processing functions, so that users can see the title summary of the mail without downloading the mail body, and can operate the mail and folder directories on the server from the mail client software. IMAP protocol enhances the flexibility of e-mail, reduces the direct harm of spam to the local system, and relatively saves the time for users to check e-mail. In addition, IMAP protocol can remember users' offline mail operations (such as moving mail, deleting mail, etc.). ) will be automatically executed the next time you open the network connection.

At present, two mail acceptance protocols and one mail sending protocol support secure server connection. Support for SSL connections is integrated in most popular e-mail client programs.

In addition, many encryption technologies are also applied to the sending, receiving and reading of e-mail. They can provide encryption strength from 128 bits to 2048 bits. One-way encryption and symmetric key encryption are also widely supported.

The first email

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For the earliest e-mail in the world, according to the data search, there are now two kinds of statements:

The first statement:

The first e-mail in the world was a short message sent by computer scientist Professor Leonard K to his colleagues.

According to Internet Weekly, the first e-mail in the world was a short message sent to a colleague by computer scientist Professor Leonard K (the time should be 1969 10 months). This message has only two letters: "LO". Professor Leonard K is therefore called the father of e-mail.

Professor Leonard K. explained, "I tried to contact another computer at Stanford Research Center near San Francisco through a computer at the University of California. What we do is log in from one computer to another. At that time, the method of L-O-G in was to enter L-O-G. So we type in L and ask each other,' Did you get L?' The other party replied,' Yes.' Then enter O, and then enter G. The system crashed before the other party received G's confirmation answer, so the first online message was' LO', which means' Hello! I'm finished. "

The second statement

197 1 year, the ARPANET funded by the U.S. Department of Defense was in full swing, and a very sharp problem appeared: the scientists involved in this project were doing different jobs in different places, but they could not share their research results well. The reason is simple, because everyone uses a different computer, and everyone's work is useless to others. They urgently need a method to transmit data between different computers through the network. Ray Tomlinson, a Ph.D. student at the Massachusetts Institute of Technology who works in ARPANET, combined a software that can be replicated between different computer networks with a communication software that is only used for single computers, and named it SNDMSG (that is, sending messages). In order to test, he used this software to send his first email on Arpad, and the recipient was himself on another computer. Although even Tomlinson can't remember the content of this email, that moment is still full of historical significance: email was born. Tomlinson chose the @ symbol as the space between the user name and the address, because this symbol is relatively uncommon and will not appear in anyone's name, and the pronunciation of this symbol also means "existence". ARPANET scientists welcomed this breakthrough innovation with great enthusiasm. Their genius ideas and research results can now be shared with colleagues at the fastest speed-unconsciously. Looking back now, many of them think that e-mail played an important role in the great success of ARPANET.

How to choose an e-mail address

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E-mail, also known as e-mail, with the wide application of computers and the Internet, has become an essential way to contact the Internet. So how to choose email is a headache for many friends. Next, I will introduce you to the selection method of email.

Before choosing an e-mail service provider, we should know what the purpose of using e-mail is and choose according to our different purposes.

If you are in frequent contact with foreign customers, it is recommended to use foreign e-mail. Such as Gmail, Hotmail, MSN mail, Yahoo Mail, etc.

If you want to use it as a network hard disk and often store some pictures and materials, then you should choose a mailbox with a relatively large storage capacity, such as Gmail, Yahoo Mail, Netease 163mail, 126mail, yeah mail, TOM mail, 2 1CN mail and so on.

If you have a computer, you'd better choose a mailbox that supports POP/SMTP protocol. You can download email to your hard disk through email client software such as outlook and foxmail, so you don't have to worry about the size of your email, and at the same time, you can prevent others from peeking at your email after stealing the password. Of course, the premise is not to leave a copy on the server. I suggest that this is mainly from the perspective of safety.

If you often need to send and receive some large attachments, such as Gmail, Yahoo Mail, Hotmail, MSN Mail, Netease 163 Mail, 126 Mail, Yeah Mail, etc. Can meet the requirements very well.

If you want to know your new email address in the first time, I suggest you use China Mobile Monternet to post at will, and there will be SMS notification when the email arrives. Unicom users can choose Ruyi mailbox.

In addition, political factors must also be considered. When using the mail service provided by domestic government agencies, it should be noted that many contents of the mail are under the monitoring of the National Security Bureau. Never use these mailboxes to post any emails that subvert the country and slander political parties, or you will have to drink free tea. If you don't have these conditions, you can use them with confidence. Xinhua mailbox, a free mailbox provided by Xinhua. Com, one of the four largest communication organizations in the world, is very stable and fast. However, the application for new users stopped in 2000. There is also the People's Daily email provided by the People's Daily, which is also very easy to use. It is difficult to register now. There is also the China Internet News Center hosted by China. Com, which has many free email functions, and it is convenient to register now.

If it is only used in China, QQ mailbox is also a good choice. With an email address of QQ number @qq.com, your friends can send you instant messages through QQ. Of course, you can also use an alias mailbox. In addition, with the acquisition of foxmail by Tencent, Tencent's technology in the field of e-mail has been greatly strengthened. So using QQ mailbox should be very reassuring.

In addition, you can choose local e-mail according to your region. For example, friends in Beijing can choose Ganlong. Com email, friends in Guangzhou can choose 2 1CN email.

Friends who use paid mailboxes should pay attention to whether the price-performance ratio of mailboxes is worth spending money on, and whether they can pay their fees for a long time. At present, Netease VIP mailbox and 188 wealth mailbox are very good, especially the design scheme of providing a variety of business cards is very user-friendly, which is strongly recommended for everyone to use.

You can also use the mailbox provided by your own broadband service provider. For example, users of Tietong can choose the new hour mailbox of 68CN Enterprise Edition.

In fact, many people have a misunderstanding about the size of attachments that support sending and receiving, and many people think that they must be large. In fact, generally speaking, some data have no more attachments than 3MB. When the attachment is large, you can use WinZIP, WinRAR and other software to compress it before sending it. At present, mailboxes basically support attachments of more than 4MB, and well-known mailboxes have provided attachment receiving and sending space of more than 10MB. Another problem that can't be ignored is that your mailbox supports large attachments. Does your friend's mailbox also support large attachments? If you can send large attachments, and your friend's mailbox does not support accepting large attachments, then it is meaningless for your mailbox to support any large attachments, so this issue is not important.

You can also choose your email address according to your most commonly used IM instant messaging software. You can often use QQ email, Yahoo email, MSN email or Hotmail email. Of course, other email addresses can also be registered as MSN accounts. Those who like to use Netease bubble will use Netease 163 mailbox.

There is another important issue that cannot be ignored. In the desktop operating system, the Windows operating system accounts for 90% of the regular share. In other words, 10% of friends use linux and Apple operating systems. Because firefox browser can't support many java script programs in WEB pages well, it is difficult for beginners to configure the browser, which means it may be difficult to access the mailbox through the web, so these friends must choose a mailbox that supports POP/SMTP function and send and receive emails through client software such as Kmail. Friends who use linux and Apple Unix operating systems are not recommended to use MSN mail and Hotmail, except POP/SMTP, because they are competitors of Microsoft. In order to prevent Microsoft from taking improper measures to block email sending and receiving, friends who use the above operating systems had better not use Hotmail and MSN mail. There is no official MSN software from Microsoft on these operating systems, and only some functions of MSN can be realized through plug-ins of chat tools.

Pronunciation and Meaning of @ in E-mail

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Ray Tomlinson is a person we can't forget in the E era: Yi Meier was born because he chose @. Tomlinson was studying a program as early as 197 1. He wants to combine the file transfer protocol of one program with the sending and receiving functions of another program, so that a letter can be sent from one host to another. After many efforts, his first email was born. At this point, the computers have just been connected through ARPANET.

Tomlinson is modest. When people asked him what he wrote in his first email, he said he couldn't remember it at all because he had experimented too many times. But the content of Tomlinson's first email recorded in Guinness World Records is the third row of letters on the computer keyboard, which is QWERTYUIOP. The first digital address in history is tomlinson @ bbn? Tenexa, this is Tomlinson's email address.

When many people asked Tomlinson why he took a fancy to @ among so many roles, he said that in order to separate his personal name from the host he used, he had to set a sign to separate his personal name from the host. He said that he took a fancy to that character at first sight, because it was simple, so Tomlinson said, "It was so conspicuous on the keyboard that I took a fancy to it at first sight, and I didn't even try other characters."

Some major e-mail addresses

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gmail

Yahoo mail

MSN mail

Hotmail mail

QQ mail

Netease 163 email address

Wang Meng Sui Xin, you

Xinhua mailbox

People's mailbox

China net mailbox

Some major electronic processing software

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Bat!

Windows Live Mail desktop

KooMail

Dream Express Dream Mail

Becky.

Foxmail

IncrediMail

Mozilla Thunderbird

Outlook Express

Mail cleaner

Select email from "Information Security, Anti-Spam". Antivirus, mailbox capacity, stability, sending and receiving speed, whether it can be used for a long time, the function of mailbox, whether it is convenient to use, and all kinds of sending and receiving methods are comprehensively considered. Everyone can choose the most suitable mailbox according to their own needs.

The principle of e-mail and the use of Outlook Express

1, mail principle