The History of Email: From ARPANET to the Modern Inbox
Email began as a simple way for researchers to leave messages on networked computers. Decades later, it remains one of the few communication systems that works across companies, countries, and devices — and still underpins much of our digital life.
Invisible but essential
Email is so ordinary now that it’s almost invisible.
You open your inbox without thinking about the system behind it. Messages arrive from banks, friends, schools, governments, and companies. Receipts, security codes, newsletters, support replies — all of it flows through the same channel.
But email didn’t begin as a product.
It began as a side effect.
Researchers were trying to make computers talk to each other. The fact that humans could leave messages along the way turned out to be just as useful.
That small shift — from computers exchanging data to people exchanging messages over computer networks — changed everything.
Unlike many technologies from that era, email didn’t disappear when something newer came along. It adapted. It spread. And it quietly became part of the foundation of digital life.
Understanding how that happened explains why email still matters today — not just as a tool, but as a system built on ideas that are becoming rare on the modern internet.
From machines to people
In the late 1960s and early 1970s, computers were large, expensive machines used mostly by universities and research labs. Networks like ARPANET were built so those machines could share resources.
At first, communication wasn’t really the goal. Users could leave text files for others on the same computer — more like digital notes than messages.
The breakthrough came when someone realised those notes didn’t have to stay on one machine.
In 1971, Ray Tomlinson sent the first message from one computer to another across a network. To make that work, he needed a way to show both who the message was for and which computer they were on. He chose a symbol that wasn’t already heavily used: @.
That simple choice still shapes every email address today.
There was no product launch. No grand announcement. Just a practical solution that turned out to scale far beyond its original purpose.
Why email spread naturally
As networks expanded through universities and research institutions, email spread because it solved real problems.
It was faster than memos.
Cheaper than post.
And it didn’t require people to be online at the same time.
That last part mattered more than it seemed. Email didn’t demand both people be present at the same time. You could send a message, walk away, and the other person could read it hours later. No interruptions. No scheduling. No need to catch someone at the right moment.
That made it perfect for work across time zones, departments, and organisations.
By the time personal computers became common and the internet opened up to the public, email was already a proven system waiting to grow.
Webmail and the internet boom
The 1990s changed everything.
Email moved from specialist environments into everyday life. Internet providers began offering personal accounts, and web-based services like Hotmail made it possible to check email from any computer with a browser.
For many people, creating an email address was their first real step onto the internet.
An email address quickly became more than a way to send messages. It became:
• A login
• An identity
• A recovery method
• A permanent point of contact
Your inbox became the place where your digital life connected.
This is also when the trade-off between free, ad-funded services and paid providers began shaping how email works — a theme that still matters today when thinking about free vs paid email.
Spam, abuse, and the fight for trust
As email grew, so did abuse.
Unsolicited marketing became spam. Spam turned into scams. Scams evolved into phishing and malware. The same openness that made email powerful also made it vulnerable.
Providers responded by building filtering systems to separate wanted mail from unwanted mail — part of why spam never really disappeared. This created a constant arms race: senders trying to get through, filters trying to block them.
Over time, much of the work needed to keep inboxes usable became invisible. Most people don’t see the systems quietly checking, scoring, and filtering messages before they ever appear.
Email didn’t become messy because it was badly designed.
It became messy because it became important.
Authentication and the hidden infrastructure
As abuse increased, the email ecosystem had to find ways to prove that messages were legitimate.
This is where systems like SPF, DKIM, and DMARC came in. They don’t make email private, and they don’t guarantee a message is safe. They simply help receiving servers judge whether a message claiming to be from a domain is likely to be genuine.
These checks happen behind the scenes, long before a message reaches your inbox. They’re part of the quiet infrastructure that keeps email working at global scale.
Most people never see this layer. But without it, trust in email would have collapsed years ago.
Messaging apps didn’t replace email — they changed its role
When instant messaging and collaboration apps appeared, many people assumed email would fade away.
Instead, its role changed.
Messaging apps took over quick conversations and real-time collaboration. Email became the place for communication that needs:
• Structure
• Clarity
• Records
• Accountability
Email isn’t always the fastest way to talk, but it’s still one of the most reliable ways to send information that needs to be kept, referenced, or shared across systems.
That’s why businesses, governments, and institutions still depend on it.
Privacy, identity, and control
As awareness of digital privacy grew, email came under a new kind of scrutiny.
People began asking harder questions:
Who runs my email?
What do they see?
What are they incentivised to do with my data?
Email also became deeply tied to identity. Lose access to your inbox, and you can lose access to everything connected to it.
That’s why some people now choose providers focused on encryption, tracking protection, or stronger account security. It’s also why using your own domain for email can matter — it separates your identity from any single company.
Email is no longer just a communication tool.
It’s part of how people maintain long-term control over their digital lives — something I explore more in how I think about email.
Why email survived when others didn’t
Many early internet tools disappeared. Email didn’t. Services like GeoCities vanished. Myspace faded from everyday use. Instant messengers like MSN Messenger and ICQ shut down or were replaced. Even once-dominant platforms such as AOL lost their central role.
Email, by contrast, never depended on a single company or app. It worked across providers, devices, and decades — which is why it’s still here.
It runs on open standards that let different providers and systems talk to each other — the same foundation that allows email authentication systems to work globally.
Another reason is flexibility. Email adapted to web browsers, then to smartphones, then to stronger security systems — all without breaking how older systems worked.
Most importantly, email fills a role that hasn’t gone away: a universal way to send messages that doesn’t require both people to be online at the same time, and works almost anywhere.
That combination is hard to replace.
Conclusion: old design principles that still work
Email came from a time when the internet was built around openness and shared standards. Those ideas helped it grow beyond its original purpose and stay useful through decades of change.
It isn’t perfect. It isn’t modern in the way new apps are. But it is resilient.
Underneath the spam filters, security checks, and login codes is a simple system for sending messages from one place to another — a system that still works across companies, countries, and devices.
That’s why email didn’t disappear.
It became infrastructure.
And like most infrastructure, you only really notice it when it stops working.
