What is email?
Electronic mail, commonly shortened to “email,” is a communication method that uses electronic devices to deliver messages across computer networks. "Email" refers to both the delivery system and individual messages that are sent and received.
Email has existed in some form since the 1970s, when programmer Ray Tomlinson created a way to transmit messages between computer systems on the Advanced Research Projects Agency Network (ARPANET). Modern forms of email became available for widespread public use with the development of email client software (e.g. Outlook) and web browsers, the latter of which enables users to send and receive messages over the Internet using web-based email clients (e.g. Gmail).
Today, email is one of the most popular methods of digital communication. Its prevalence and security vulnerabilities also make it an appealing vehicle for cyber attacks like phishing, domain spoofing, and business email compromise (BEC).
How does email work?
Email messages are sent from software programs and web browsers, collectively referred to as email ‘clients.’
Individual messages are routed through multiple servers before they reach the recipient’s email server, similar to the way a traditional letter might travel through several post offices before it reaches its recipient’s mailbox.
Once an email message has been sent, it follows several steps to its final destination:
- The sender’s mail server, also called a Mail Transfer Agent (MTA), initiates a Simple Mail Transfer Protocol (SMTP) connection.
- The SMTP checks the email envelope data — the text that tells the server where to send a message — for the recipient’s email address, then uses the Domain Name System (DNS) to translate the domain name into an IP address.
- The SMTP looks for a mail exchange (MX) server associated with the recipient’s domain name. If one exists, the email is forwarded to the recipient’s mail server.
- The email is stored on the recipient’s mail server and may be accessed via the Post Office Protocol (POP) or Internet Message Access Protocol (IMAP)
- These two protocols function slightly differently: POP downloads the email to the recipient’s device and deletes it from the mail server, while IMAP stores the email within the email client, allowing the recipient to access it from any connected device.
To continue the postal system analogy,
imagine Alice writes a thank-you note to Bob. She hands the letter to the mail carrier (MTA), who brings it to the post office to be sorted. At the post office, a processing clerk (SMTP) verifies the address written on the envelope. If the address appears to be written correctly and corresponds to a location that can receive mail (MX server), another mail carrier delivers the letter to Bob’s mailbox. After picking up the mail, Bob might keep the note in his desk drawer, where he can only access it at that location (POP) or put it in his pocket to read at any location (IMAP).
The current version of the POP protocol is named POP3.
The main components of an email message
A mail message transfer agent is software that transfers emails between the computers of a sender and a recipient. No two email addresses can be identical, as each complete address must be unique.
Typically, an email message consists of two main components: header and body.
Header
Each email message comes with a header that's structured into various fields. These fields contain important information regarding the sender and the recipient(s). However, the content of the email header varies, depending on the email system being used.
Typically, an email header contains the following information:
01)Subject
This provides a summary of the message topic and is displayed in a separate line above the message body. For example, a subject line might say "Company mission statement" or "Employee Stock Purchase Plan."
02)Sender (From)
This field is the sender's email address. A display name can also be shown instead if it's associated with the email address. Most email clients fill out this field automatically.
03)Date and time received (On)
This field shows the local time and date when the message was composed. It's a mandatory header field that's filled automatically by most email clients.
04)Reply-to
If a user clicks on the Reply button, this field automatically populates the message with the sender's email address, which now becomes the "recipient."
05)Recipient (To)
This field shows the first and last name of the email recipient, as configured by the sender.
Recipient email address. This is the email address of the recipient or where the message was sent.
06)Carbon copy (CC)
The carbon copy field includes the email addresses of the people who need to receive the email but aren't expected to reply. When a person presses Reply All, all of the CC addresses receive the response.
07)Blind carbon copy (BCC)
If a sender doesn't want their recipient to find out who else received the email, they could use the BCC field to enter those addresses. The addresses in the BCC list don't receive responses when someone presses Reply All.
Body
This is the content of the email. It may contain anything the user wishes to send, including text, videos or file attachments. Depending on the email client used, the email body can be formatted in either plain text or HTML. While plain text messages can't contain special formatting or multimedia elements, HTML emails enable special formatting and inclusion of multimedia options within the body of the message. The message body may also include signatures or automatically generated text that the sender's email system inserts.
Attachments
This field contains any files that are attached to the message.
What is an email client?
- An email client is a software program or web application that enables users to send, receive, and store emails. Popular email clients include Outlook, Gmail, and Apple Mail.
Software- and web-based email clients each have advantages and disadvantages. Desktop email clients often come with more robust security capabilities, streamline email management across multiple accounts, provide offline access, and allow users to back up emails to their computers. By contrast, web-based clients are usually cheaper and easier to access — since users can log in to their account from any web browser — but are reliant on an Internet connection and can be more susceptible to cyber attacks.
Originally, ‘email’ referred to desktop email clients and ‘webmail’ referred to web-based email clients. Today, the term ‘email’ encompasses both systems.
What is an email address?
An email address is a unique string of characters that identifies an email account, or ‘mailbox,’ where messages can be sent and received.
Email addresses are formatted in three distinct parts: a local-part, an “@” symbol, and a domain.
For example, in the email address employee@example.com,
“employee” - denotes the local-part
“example.com” - denotes the domain.
Imagine addressing a letter: the domain signifies the city where the recipient lives, while the local-part specifies the street and house number at which the letter can be received.
Local-part
The local-part tells the server the final location of an email message.
It may include a combination of letters, numbers, and certain punctuation marks (like underscores). The maximum number of characters for an email address (including both the local-part and domain) is 320, though the recommended length is capped at 254 characters.
Domain
The domain may be a domain name, like example.com, or an IP address, like 192.0.2.0.
In the former case, the SMTP protocol uses DNS to translate a domain name into its IP address before delivering the message to the next server.
Like the local-part, the domain also has to adhere to certain formatting requirements established by the Internet Engineering Task Force (IETF).
Approved domain names may include a combination of uppercase and lowercase letters, numbers, and hyphens.
An email address can also be formatted with an IP address in brackets instead of a domain name, although this is rare. The character limit for a domain name is 63.
Some Examples of Email Servers
- Microsoft Exchange Server
- Dovecot
- Fastmail
- hMailSerever
- IceWarp
- Sendmail
- Zimbra
- Axigen
- Exim
How to create mail account
To create an email account, you can typically:
- Go to the email provider's website
- Click Sign up or Create account
- Enter your desired username and password
- Enter your basic details, such as your name, phone number, and country
- Agree to the terms and conditions
- Click Create Account
- Enter the verification code sent to your phone
- Go to the Google Account sign-in page
- Click Create account
- Select if the account is for personal use, a child, or work or business
- Follow the on-screen steps
- Enter your first and last names
- Choose a password that's at least 8 characters long and includes upper and lowercase letters and numbers
- Enter your birthday and gender
- Verify your phone number by entering the code sent via text message or voice call
Advantages of email
Email is a fast, reliable and portable way of communicating with others.
The following are some common benefits of using email for both personal and professional purposes:
01.Cost-effectiveness - There are various free email services available to individuals and organizations. Once a user is online, there are no additional charges for the service.
02.Flexibility - Email provides users with a nonurgent communication process that enables them to send a response when it's convenient for them. This also encourages users to communicate regardless of their different schedules or time zones.
03.Easy access - If the user has access to the internet, then email can be accessed from anywhere at any time.
04.Speed and simplicity - Emails are quick and easy to compose, with information and contacts readily available. They can also be exchanged quickly with minimal lag time.
05.Mass delivery - Email makes it possible and easy to send one message to large groups of people.
06.Message filtering- Email enables users to filter and categorize their messages. This can prevent the visibility of unwanted emails, such as spam and junk mail, while also making it easier to find specific messages when they're needed.
07.Message storage and retrieval - Email exchanges can be saved and searched for easy retrieval. This enables users to keep important conversations, confirmations or instructions in their records and quickly retrieve them if necessary.
Disadvantages of email
Is email secure?
Although email is often used to exchange confidential information, it is not a secure system by design.
This makes it an attractive target for attackers, who may intercept an unencrypted message, spread malware, or impersonate legitimate organizations.
Other email security threats include social engineering, domain spoofing, ransomware, spam, and more.
One of email’s most significant vulnerabilities is its lack of built-in encryption, leaving the contents of an email visible to any unauthorized party that might intercept or otherwise gain access to the message.
In an attempt to make email more secure, many email clients offer one of two basic encryption capabilities:
Transport Layer Security encryption (or ‘TLS encryption’) and end-to-end encryption (or 'E2EE').
During TLS encryption, messages are encrypted during transit (from user to server or server to user), and the email service provider retains possession of the private key used to set up this encryption.
The email service provider can therefore see the unencrypted contents of the email. During end-to-end encryption (from user to user), messages can only be decrypted by the sender and recipient of the email.
How does Cloud flare help secure email?
Cloud flare Area 1 Email Security is a cloud-based email security solution that helps prevent a number of email threats, including phishing, malware, Business Email Compromise (BEC), and email supply chain attacks.
It uses robust machine learning models to identify risks before they reach user inboxes, and integrates with common cloud email providers to enhance existing detection and mitigation capabilities.
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