Messages on one machine
Electronic mail began as a convenience on shared computers. In the early 1960s, universities and research labs used time-sharing systems, in which many people logged in to a single large machine from separate terminals. Users wanted a way to leave notes for each other without printing or walking down the hall.
One early example, often cited, was a mail command on MIT’s Compatible Time-Sharing System in the mid-1960s. It let a user append a message to a file belonging to another user. Other time-sharing systems of the period developed similar tools, so there is no clean “first email” in a single place. Such systems only worked within one computer.
Mail between computers
The step that made email a networked service came with the ARPANET, the research network that began operating at the end of the 1960s. Programmers wanted a way to send messages between machines at different sites, not just between users of the same machine.
Around 1971, Ray Tomlinson, an engineer working on the network, adapted existing local mail software to send messages across it. He is widely credited with choosing the @ symbol to separate the user’s name from the name of the machine, a convention that survived to the present day. Details of the exact date and of earlier ideas are sometimes debated, but the general decade and his role are well established.
Email quickly became one of the most popular uses of the network. Researchers added features such as replying, forwarding, and lists of messages, and discussion groups appeared in which a message to one address reached many people.
Standards and growth
Because many networks and computer types existed, agreement on formats mattered. During the 1970s, a series of informal documents described message headers and how mail should be transferred. By the early 1980s, the Simple Mail Transfer Protocol, known as SMTP, was published and became the basis for sending mail between servers. It is still used today, although much extended.
Other protocols dealt with how users retrieved mail. Two common types are POP, which downloads messages to one computer, and IMAP, which leaves them on a server so that several devices can see the same mailbox. This distinction became more important with the spread of phones and tablets.
Networks beyond the ARPANET, including academic and commercial ones, built gateways so that messages could pass between them. The addressing system based on domain names, introduced in the 1980s, made addresses easier to manage across the growing internet.
Mail for everyone
In the 1980s, mail was mostly used by researchers, students and technical staff, along with users of company systems. Commercial online services and bulletin board systems offered local or private mail to subscribers, usually with limited connection to the wider world. As the internet opened to the public in the 1990s, internet service providers began issuing addresses to households.
Graphical programs made mail friendlier. Instead of typing commands, users saw lists of messages, folders and attachments. Standards such as MIME allowed attachments like pictures and documents to travel in messages, which had originally been plain text.
Then web-based mail appeared in the mid-1990s. A user could open an account in a browser, with no software to install, and read it from any computer. Free services with large storage allowances spread widely, and this changed how people thought about keeping messages: instead of deleting, many began to archive and search.
Email at work
Businesses adopted mail for internal memos and communication with customers, and it gradually reshaped the office. Messages replaced many printed memos and phone calls, and also created new habits such as copying colleagues and checking an inbox constantly. The effect of mail on office life is discussed further in the topic of workplace email, and it fed into broader changes described under office automation. Whether it saved time overall is debated, since it lowered the cost of sending messages and increased the number received.
Spam, security and trust
The openness that helped mail spread also made it a target. Unsolicited bulk messages, known as spam, appeared in volume from the 1990s and remain a persistent problem. Fraud attempts that imitate banks or colleagues, known as phishing, rely on the fact that the original mail protocols did not verify senders.
Over time, providers introduced filters, sender-verification methods and encryption between servers. These measures reduce abuse but do not remove it, and their adoption varies. Privacy is a further concern: ordinary mail is not necessarily private end to end, and messages stored on servers may be accessible to the provider or subject to legal requests, which links to broader questions of data protection.
Competition and change
Email now shares attention with messaging apps, workplace chat tools and social media, which handle many short or informal exchanges. Even so, email remains widely used for accounts, receipts, formal communication and as a basic identity on many online services. Its core design, a message addressed to a name at a domain, has stayed recognizable for more than fifty years, which is unusual in computing.
Why the history matters
Email shows how a simple utility can grow into infrastructure. It began as a tool for people sharing a machine, spread with the networks that connected those machines, and benefited from open standards that anyone could implement. Its weaknesses, especially spam and weak sender verification, also show the costs of building a system for a small trusted community and later opening it to everyone.