Email

You can send notes on a screen.

These notes move through computer networks. This is called email. It is like a digital version of paper mail.

To send a note, you need an address. This address has a special symbol. It uses the @ sign. This sign helps the note find the right person.

When you send a note, it goes to a server. A server is a computer that holds your mail. It can store the note for you.

The person you are writing to does not need to be online. The server waits for them to connect. Then, they can read your note.

Email can also carry more than just words. You can send pictures too. It is a very helpful way to talk!

Email is a way to send digital messages. It works over computer networks like the Internet. You can think of it as a digital version of paper mail.

To send a message, you need an email address. This address uses the @ symbol. The part before the @ is the local part. This is often a username. The part after the @ is the domain name.

Email uses a store-and-forward model. This means messages are kept in a safe place while they move. You do not both need to be online at the same time. Instead, you send your message to a mail server. A server is a computer that accepts and stores messages.

When you send a message, a program called an MUA formats it. The message has two main parts called content. The first part is the header. It lists the sender and the date. The second part is the body. This is where your actual message lives.

In the past, email was only for plain text. Now, a system called MIME lets you send pictures and other files. This makes email a very useful tool for daily life.

Email is a way to send digital messages over computer networks. It acts like a digital version of the mail we send in envelopes. Today, email is used everywhere in the world. People use it for business, school, and even for fun. Most people need an email address to join in these daily activities. An address has a local part and a domain name. These two parts are separated by the @ symbol.

Email works using a system called store-and-forward. This means messages are stored in a safe place while they travel. You do not have to be online at the same time as the person you are messaging. First, a program called a mail user agent formats your message. It uses a protocol called SMTP to send the text to a mail server. The server looks at the domain name to find where to go next. It uses the Domain Name System to find the right path. Finally, the message is delivered to the recipient's mailbox.

Computers began sending messages to each other in the early 1960s. This happened during a time called time-sharing. In 1965, a project at MIT showed how this could work. The first network mail on ARPANET arrived in 1971. This was a big step because it used the @ symbol we use today. Different companies like IBM and Xerox made their own systems in the 1970s. In 1983, the SMTP system was put on the ARPANET. This helped make email more organized for everyone.

There are many specific rules that make email work correctly. For a long time, email was only for plain text. Then, a system called MIME was added to allow images and other files. An email has two main parts called content. The header contains details like the sender, the date, and the subject. The body is where the actual message is written. The header and body are separated by a blank line.

Using email is a very common part of modern life. You might see an inbox filled with new messages to read. You can choose to save, delete, or respond to these messages. Most people use a webmail service or a special app on their computer. These tools make it easy to talk to people far away. Even if a server is busy, the mail can wait for up to five days. This helps make sure your message eventually arrives.

Electronic mail, or email, is a method for transmitting and receiving digital messages across computer networks. It functions as the digital counterpart to physical mail, using electronic devices to communicate. Today, email is a ubiquitous medium used in business, government, education, and entertainment. Most people consider having an email address a basic necessity for modern life. An email address typically follows a specific structure. It consists of a local-part, followed by the @ symbol, and then a domain name.

Modern email systems rely on a store-and-forward model. This model allows messages to travel even if the sender and recipient are not online at the same time. The process begins when a user employs a Mail User Agent (MUA). This is the software or interface used to read and write messages. The MUA formats the message and uses a submission protocol. This protocol is a specific profile of the Simple Mail Transfer Protocol (SMTP). The MUA sends the content to a local Mail Submission Agent (MSA).

The MSA then handles the routing of the message. It looks at the destination address to find the Fully Qualified Domain Address (FQDA). The part before the @ sign is the username, or local part. The part after the @ sign is the domain name. To find the correct server, the MSA uses the Domain Name System (DNS). The DNS server provides MX records, which are mail exchange records. These records list the specific mail exchange servers for that domain. The message is then sent to a Message Transfer Agent (MTA) server. This server might forward the message through several other MTAs before it reaches the final Message Delivery Agent (MDA). The MDA finally places the message into the recipient's mailbox. The recipient's MUA then retrieves the message using either POP3 or IMAP protocols.

The history of email began with computer-based messaging in the early 1960s. This was made possible by a development called time-sharing. In 1965, a notable implementation occurred through the CTSS project at MIT. By 1971, the first ARPANET network mail was sent. This historic transmission introduced the @ symbol to designate a user's system address. Throughout the 1970s, companies like IBM, CompuServe, and Xerox developed their own in-house mail systems. In 1983, SMTP was implemented on the ARPANET. While different systems competed for dominance, the combination of SMTP, POP3, and IMAP eventually became the global standard after 1995.

An email message is organized into two main sections called content. The first section is the header, and the second is the body. The header contains structured fields that provide essential information. These fields include "From", "To", "CC", "BCC", "Subject", and "Date". Each field name is followed by a colon and a value. The header and the body are always separated by a single blank line. Originally, email was a text-only medium using ASCII characters. However, the introduction of Multipurpose Internet Mail Extensions (MIME) changed this. MIME allows email to carry expanded character sets and multimedia content, such as images.

Sometimes, delivering an email can take longer than expected. There are several technical reasons why a message might be delayed. Large attachments require more time to transmit across the network. A message might also need to pass through many different servers. Sometimes, a mail server is overloaded due to a denial-of-service attack or a large amount of spam. If a server is busy, it may queue the mail. In fact, mail can be queued and retried for up to five days. If it cannot be delivered after that, the sender is notified of a permanent failure.

Email is deeply connected to the broader systems of global communication. It operates across local area networks and the massive infrastructure of the Internet. While it favors reliability over speed, it remains a fundamental tool for digital interaction. Users can interact with email through various interfaces, such as a webmail service or a dedicated desktop client. Even as newer technologies emerge, the structured protocols of email ensure that messages move predictably across the globe.