The Origins of ARPANET and the Seed of Modern Email

When the Internet fit in a room

In the late 1960s, during the Cold War, a group of researchers from the Advanced Research Projects Agency of the U.S. Department of Defense (ARPA) sought a way to connect computers between universities to share scientific information.

In 1969, ARPANET was born, an experimental network that connected four nodes: UCLA, Stanford, Santa Barbara, and Utah. The first data transmission was as symbolic as it was fragile: the message was supposed to be “LOGIN”, but the network crashed after the first two letters. Only “LO” arrived.
It was the first error… and the first step toward the Internet.

The Birth of ARPANET

ARPANET was designed as a decentralized network, capable of maintaining communication even if one of its nodes went down. Its initial goal was technical and military, but it quickly became a laboratory of ideas about how to exchange information between people through machines.

The system used the NCP (Network Control Protocol), a precursor to today’s TCP/IP, and already implemented concepts like routing, data packets, and intermediate servers. It was the seed of what we now call the Internet.

Ray Tomlinson and the First Email

In 1971, an engineer named Ray Tomlinson, working at BBN (the company contracted by ARPA), devised a way to send messages between users of different computers within the network. To distinguish user and machine, he chose a symbol that already existed on keyboards but wasn’t used in proper names: the @ (at).

His first message, sent between two DEC computers connected side by side, was probably something trivial —“QWERTYUIOP” according to him—, but it changed the history of human communication.

Email had been born.

From Machine Communication to Person-to-Person Email

During the 1970s and 1980s, email became the most used application on ARPANET.

The first concepts of inbox, distribution lists, and automatic replies were born, and the protocols we still use today were standardized:

• SMTP (Simple Mail Transfer Protocol) – 1982
• POP (Post Office Protocol) – 1984
• IMAP (Internet Message Access Protocol) – 1988

Email went from being an engineer’s tool to becoming the universal language of digital communication.

From Spam Chaos to Sender Authentication

Email’s success brought with it its great weakness: the absence of native authentication. The SMTP protocol didn’t verify if the person sending a message was really who they claimed to be, which opened the door to spam, spoofing, and phishing.

To mitigate these problems, standards emerged:

• SPF (Sender Policy Framework) – to validate authorized servers.
• DKIM (DomainKeys Identified Mail) – to digitally sign messages.
• DMARC (Domain-based Message Authentication, Reporting and Conformance) – to establish validation policies.

Even so, email still couldn’t offer verifiable legal proof of sending, delivery, or content.

From the First “@” to Certified Email

Fifty years after that experiment on ARPANET, email has evolved to become a universal communication system, but also a channel where digital trust is fundamental.

That’s where the concept of certified email was born, which transforms traditional email into a communication with probative validity, capable of proving:

• What was sent.
• Who it was sent to.
• When it was made available.
• And that the content remained intact.

If ARPANET was the first attempt to guarantee the technical continuity of messages, certified email today represents the guarantee of their authenticity and legal validity.

What started as an experiment to connect machines ended up connecting people.
Today, certified email also connects trust, evidence, and digital security.

Conclusion

From military laboratories to digital trust systems, the history of email is also the history of how we learned to trust the messages we exchange.

The @ symbol united names and machines; electronic certification now unites technology and legal certainty.

In each evolution —from ARPANET to eEvidence— there is the same purpose: that information arrives, is preserved, and can be proven.