What Is Email?

E-mail is a communication method that provides information exchange by electronic means. It is the most widely used service on the Internet. Through the web's email system, users can send it at a very low price (no matter where they are sent, they only need to pay for the Internet), a very fast way (can be sent to any specified destination in the world within a few seconds), Connect with web users anywhere in the world.

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E-mail is a communication method that provides information exchange by electronic means. It is the most widely used service on the Internet. Via network

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Email services are provided by dedicated servers, Gmail, Hotmail, Netease

1. There are three parts of letters and letter archives. Users use passwords to open their own mailboxes, and perform various operations such as sending, reading, editing, forwarding, and archiving. System functions are mainly implemented by software.

3. Email communication takes place between mailboxes.

The user first opens his own mailbox, and then sends a mail to be sent to the other party's mailbox by typing a command. Mail is delivered and exchanged between mailboxes, and it can also be delivered and exchanged with another mail system. The recipient uses specific

1. The TCP protocol is used for mail transmission between mail servers. Why is the mail sometimes lost?

The SMTP protocol between the mail servers uses a TCP connection, which can ensure that the mail is accurately transmitted between the mail servers. However, due to the failure of the mail server, such as insufficient mail space, the mail cannot be transmitted and lost.

2. Why doesn't the sender's user agent send the message directly to the recipient's user agent, but instead transmits it through the mail server?

Due to the limitations of the user's computer performance, programs that can't send and receive emails can't be run, and can't run and connect to the Internet without interruption. Therefore, the letters can only be temporarily stored in the mail server, and users can download them when needed.

Email spam

There is no very strict definition of spam. Generally, any email that is forcibly sent to a user's mailbox without the user's permission.

Prior to the emergence of spam emails, a person named Sanford Wallace (or Spamford or "Spam Blessing") in the United States set up a company to provide paid advertising fax services to customers of other companies. Resentment from the recipient and wasted paper caused US legislation to ban unsolicited fax advertisements. Then spam turned advertisements into e-mails, and spam came out of nowhere.

A mail virus is a virus that spreads through email. Usually it is caught in the attachment of the email. After the user runs the virus program in the attachment, the computer will be infected. It should be noted that email itself does not generate a virus, it is just a parasitic place for the virus.

Email bomb Email bomb is one of the oldest anonymous attacks. By setting up a machine to send a large number of emails to the same address continuously, the attacker can exhaust the bandwidth of the recipient's network. Because this attack method is simple and easy to use, there are also many tools for sending anonymous emails, and as long as the other party knows the specific email address, the attack can be performed, so this is the most worthwhile defense method.

Email bombs are arguably the most "popular" method of pranks in cybersecurity today, and these special programs used to make pranks are also called E-mailBomber. When someone or a company's actions cause dissatisfaction with a good person, this good person will use this method to launch an offensive to vent private anger. This attack method not only interferes with the normal use of the user's email system, it can even affect the security of the server system where the email system is located, causing the entire network system to be paralyzed, so the email bomb is extremely powerful Cyber weapons.

E-mail advertising: E-mail advertising is a form of online advertising that uses e-mail as a carrier. E-mail advertising may be all advertising information, or some useful related information may be interspersed in e-mail. It may be one-time, It may be multiple or regular. Under normal circumstances, a network user needs to agree to be added to the email advertisement mailing list in advance, in order to express consent to accept such advertising information, he will then receive email advertisements, which is a model of marketing permission. Email ads that are received without permission are often considered spam.

E-mail Filter E-mail Filter (EmailFilter) can automatically categorize received e-mails based on the information contained in the e-mail and store them in the corresponding folder or mail box reading software. For example, all messages from Uncle Joe of a user may be placed in a folder named "Uncle Joe". Filters can also be used to block or receive emails from specified sources.

Email Database A specially formatted database containing emails stored on your computer. After receiving / sending each email, each received / sent email is saved in the database. This database will be scanned when your computer is fully scanned. In real-time monitoring mode, all incoming and outgoing emails are scanned for viruses.

Email spam prevention

^[1] Method 1: Give your mailbox a "good name". If your username is too simple or too common, it can be easily targeted. Many people are accustomed to using their pinyin as their username, but they are generally too simple to be easily caught by spammers. Therefore, when applying for a mailbox, you may wish to create a more protective username, such as a combination of English and numbers, as long as possible, so as to be less harassed by spam.

Method 2: Avoid leaking your email address. When browsing the page, do not register your e-mail address everywhere, and do not easily tell others. When friends leave email addresses for each other, you can take a flexible approach. You can rewrite it as a friend to know at a glance. E-mail collection The software does not recognize it and prevents it from being attacked by spam.

Method 3: Don't just respond to spam. When you receive spam, no matter how angry you are, do nt respond. Silent is golden here, because once you reply, you are telling the spammer that your address is valid, which will attract more Spam. There is also a trick. In order to prove the validity of the E-mail address, many spammers often say in an email in apologetic tone: "If you do not need our mail, please reply and we will no longer send you mail. "If you really reply, you are taken to them. The best way is to ignore them and put the sender on the rejection list;

Method 4: Use specialized software for anti-spam. Such software is generally available on the market. For example, BounceSpamMail software can be used to reply to spammers, telling them that the email address sent is invalid, to avoid repeated harassment of spam. And McAfeeSpamKiller can also prevent spam, and automatically reply to the spammer with "bounce" and other error messages to prevent receiving similar emails again.

Method 5: Use the mail management and filtering functions. Outlook Express, Foxmail, and qqmail all have very good mail management functions. Users can filter mails by setting rules such as mail domain name, mail subject, source, and length in the filter. Spam messages generally have relatively uniform topics, such as "promotion" and "sex". If you don't want to receive this type of email, you can try to set the filtering subject to include characters of these keywords.

Method 6: Learn to use the remote mailbox management function. Some remote mailbox monitoring software can regularly check the remote mailbox, display the subject, sender, message size and other information. You can use this information to determine which are your normal emails and which are spam, and then directly delete those spam from the mailbox Instead of downloading a bunch of messages to your local mailbox and deleting them each time.

Method 7: Select a good service website to apply for an email address. China does not have legislation against spam, nor does it lead to the development of new anti-spam technologies. The monitoring of spam is mainly based on the credit of Internet users and service providers to filter spam. Good service providers are better equipped to develop their own spam filtering systems.

Method 8: Use a paid mailbox with service guarantee. The stability of the paid mailbox is better than the free mailbox. With the emergence of new services with better technology and the emergence of two-way authenticated email systems in the future, spam will gradually leave people's lives.