How does e-mail convey information?

E-mail transmission is accomplished through the system software of Simple Mail Transfer Protocol (SMTP), which is an e-mail communication protocol under the Internet.

E-mail transmission process:

1. E-mail system is a new type of information system, which is the product of the combination of communication technology and computer technology.

E-mail transmission is accomplished through the system software of Simple Mail Transfer Protocol (SMTP), which is an e-mail communication protocol under the Internet.

2. The basic principle of email is to establish an "email system" on the communication network, which is actually a computer system.

The hardware of the system is a high-performance and large-capacity computer. As the storage medium of mailbox, hard disk divides a certain storage space for users as their "mailbox", and each user has his own e-mail. And determine the user name and password that users can modify at will. The storage space includes three parts: storing received letters, editing letters and filing letters. Users use passwords to open mailboxes and perform various operations, such as sending letters, reading letters, editing, forwarding and archiving. The system functions are mainly realized by software.

E-mail communication is between mailboxes.

The user first opens his mailbox, and then sends the mail that needs to be sent to the other person's mailbox by typing the command. Mail is delivered and exchanged between mailboxes or with another mail system. When receiving a letter, the recipient uses a specific account to retrieve the letter from the mailbox.

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 many users' e-mails. 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 will store the message in the recipient's e-mail box and notify the recipient that a new mail has arrived. After the receiver connects to the server through the mail client program, he will see the notice from 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 email arrives, the ISP host will move the email to the user's email box and notify the user of the new email. 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 ISP host of the recipient, 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 name of the account that the user applied for. 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.