Introduction to email

What is email?

Electronic mail (also known as email or e-mail) is one of the most commonly used services on the Internet, allowing people to send messages to one or more recipients. Email was invented by Ray Tomlinson in 1972.

Why use email?

The operating principle behind email is relatively simple, which has quickly made it the most popular service used on the Internet.

As with a traditional postal service, for your message to reach your recipient, all you need to know is their address. Its two main advantages over "paper mail" are the speed at which the email is sent (practically instantaneous) and the lower cost (included with the cost of an Internet connection).

What's more, email can be used to instantaneously send a message to several people at once.

Email addresses

Email addresses (both for senders and recipients) are two strings separated by the character "@" (the "at sign"):

The right-hand part describes the domain name involved, and the left-hand part refers to the user who belongs to that domain. One or more mail servers (MX records in the Domain Name System) correspond to each domain.

An email address can be up to 255 characters long and can include the following characters:

  • Lowercase letters from a to z;
  • Digits
  • The characters ".","_" and "-" (full stop, underscore, and hyphen)

In practice, an email address often looks something like this:

Ask a question
CCM is a leading international tech website. Our content is written in collaboration with IT experts, under the direction of Jean-François Pillou, founder of CCM reaches more than 50 million unique visitors per month and is available in 11 languages.


This document, titled « Introduction to email », is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM (