Ray Tomlinson: the father of @ and the engineering of the first email

The architect of modern email

The development of email is one of the most influential milestones in Internet history. And at the center of that advance is Ray Tomlinson, an engineer at BBN Technologies, credited with creating the first email system between networked machines.

Before Tomlinson, there were rudimentary messaging mechanisms within the same computer. His innovation consisted of allowing sending messages between users working on different machines, connected through ARPANET, the precursor to the Internet. This conceptual leap transformed technical communication into a form of global human interaction.

For this system to be possible, it was necessary to define a clear structure to identify each user on each machine. Tomlinson solved this challenge with a brilliant and seemingly simple choice: the @ symbol.

The @: a decision that changed history

Tomlinson needed a character that didn’t usually appear in usernames and that, at the same time, intuitively indicated the relationship between the person and the system to which they belonged.

He chose the at symbol for an elegant reason: the message was addressed to a user at a specific server.

Thus was born the user@machine syntax, which later became user@domain. The @ met all requirements: it was uncommon, clear, and semantically coherent. The structure Tomlinson designed endures today unchanged, used billions of times a day worldwide.

His contribution defined not only a technical standard, but the basic grammar of digital identity.

A brilliant system… but without probative evidence

Tomlinson’s design gave the world a communication system that was fast, interoperable, and universal. Over time, email became the first great asynchronous channel in history, fundamental for businesses, administrations, and users from all countries.

But there was a structural limit: email, as it was created, did not include mechanisms for legal proof.

The Simple Mail Transfer Protocol (SMTP RFC 5321), the protocol that defines and regulates email, allows sending, forwarding, and receiving messages. However, it was not conceived to:

• legally accredit the content sent,
• verifiably demonstrate delivery,
• indisputably establish the date and time of transmission,
• or identify the parties involved with guarantees.

That is: Tomlinson created communication, but not evidence of communication.

From delivery to proof: the natural evolution of email

Decades later, the massive digitalization of procedures, contracts, and legal processes made a need evident: endowing email with legal security without altering its original simplicity.

This evolution came through Electronic Registered Delivery Services (ERDS), such as those implemented by eEvidence. Their function is clear: convert conventional email into a certifiable medium, capable of generating verifiable proof of sending, content, and delivery.

While Tomlinson gave us the method to send messages across the network, modern email certification provides:

• cryptographic fingerprints to guarantee integrity,
• timestamps to establish when,
• verifiable technical records of the message’s journey,
• and an evidence document that cannot be altered.

Thus, the original email architecture receives the missing piece to be fully reliable in business and legal environments: irrefutable proof.

Ray Tomlinson laid the foundations of modern digital communication with an idea that seemed simple, but changed the world: sending messages between machines using a universal identifier based on @.

Today, more than half a century later, that idea remains intact.

The natural evolution of email —the incorporation of certification mechanisms and legal evidence— does not replace Tomlinson’s creation, but perfects it. On that light and interoperable architecture, a layer of trust, traceability, and legal validity has been built, essential in the digital age.

Tomlinson’s legacy not only endures: it has been reinforced.

Email is no longer just communication. It is verifiable communication.