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25 email facts worth knowing 

email facts
By Drazen Vujovic. Reviewed by: James Rose. Last Updated June 17, 2024

You’re probably not too crazy about email, but let’s face it — you, me, and everyone who does any kind of work couldn’t live without it. Though we have many other ways to send messages, email remains by far the most widespread communication channel.

This isn’t just an opinion, but a well-documented fact (as you’ll see down below). We’ve prepared some very interesting email facts for you, so grab your popcorn and buckle up.

Historical facts

historical email

1. Email is probably older than you

Ray Tomlinson sent the first email in 1971. Yes, that was more than 50 years ago.

Tomlinson was a computer programmer working on ARPANET, the precursor to the modern Internet. The first email was a test message “QWERTYUIOP” sent between two of Tomlinson’s computers that were side by side.

2. Queen Elizabeth II sent an email in 1976

Speaking of the ARPANET system, we have to mention that Queen Elizabeth II sent an email message using this system in 1976. This made her the first head of state to do so.

3. The first commercial email client was MSMail 

Microsoft launched MSMail, the first commercial email client in 1988. Though revolutionary at the time, MSMail was replaced in the following decade by Microsoft Outlook.

4. Free email became the thing in the mid-1990s

Hotmail was a pioneer in the field of free email services. Launched by Sabeer Bhatia and Jack Smith in 1996, Hotmail offered free email accounts with web-based access, which soon helped the company reach well over 300 million users.

Yahoo followed Hotmail’s example and started offering free email services in 1997.

5. Email became a global phenomenon in the early 2000s

The number of email users breached the one billion threshold in the early 2000s. According to media reports, more than 1.2 billion people used it in 2005 — up from 505 million just five years earlier. 

The current state of email 

free email services

6. More than half of the world’s population uses email

There are well over 4.3 billion email users in the world today. More impressively, this number has been growing year-on-year ever since the introduction of email services. By the end of 2026, it is projected to reach more than 4.7 billion.

7. Business people receive a mind-bending number of messages daily

Reports show that the average business person gets more than 100 emails per day (121, to be exact). This figure is insane, but you should take it with a pinch of salt — it’s not the global average, but rather the US standard.

Related: How to reduce back-and-forth emails

8. Email users are very active

Users send over three million email messages every second. Given the total number of users, this means that 0.7% of them send a message every second.

9. Gmail dominates the market

Gmail is the powerhouse of the global email market — it serves 1.5 billion users. iCloud mail is the runner-up with 800 million clients, while Outlook (400 million), Yahoo (230 million), and Proton (50 million) complete the top five list.

10. Users have a lot to say in their messages

A typical email contains 434 words. This translates into 3.3 minutes of reading time. However, the analysis focuses on marketing emails exclusively, so the average across all industries might be different. 

Email security

email security

11. Spam messages are all over the place

Cybersecurity companies report that malicious actors send more than 3.4 billion spam messages every day. These mostly contain malicious links that trick recipients into visiting spoof websites or downloading malware.

Related: How secure is email? Hint: not secure enough

12. Phishing attacks jeopardize all types of organizations

Although they aren’t a new concept, phishing attacks are still extremely efficient. It looks like over 90% of organizations have fallen victim to phishing attacks in 2022. This represents a 29% increase year-on-year. 

13. The human element is to blame

Three-quarters of all security breaches include the human element. According to the Verizon Data Breach Investigations Report, this has to do with social engineering, privilege misuse, stolen credentials, and the lack of knowledge about malicious threats.

14. Phishing websites keep popping up

A brand new phishing site pops up every 20 seconds

15. Hackers often target accounting practices

Accounting firms are ranked the fifth most targeted sector for cybersecurity threats. That’s one of the main reasons why bookkeeping and accounting firms use modern client communication tools that put email to shame.

Interesting facts about email marketing

Gmail market domination

16. This channel has a high ROI

The average return on investment (ROI) in email marketing is 4,000%. Simply put, you can expect to earn $40 for every dollar invested in this marketing channel. With that said, it’s easy to see why marketers pay so much attention to email campaigns.

17. Campaigns get better with A/B testing

Email campaigns don’t allow you to just set it and forget it (at least not if you want to make them more efficient). Studies reveal that running A/B tests on your emails increases their ROI by a staggering 82%.

Related: How to streamline your workflow with automated email reminders

18. It’s one of the best marketing tools

Nearly 80% of marketers claim email is one of their top three most effective channels for marketing. This can hardly surprise anyone, bearing in mind the ROI we mentioned above. 

19. It’s even more important for B2B companies

Some types of businesses are particularly prone to email campaigns. For instance, a huge portion of B2B marketers (40%) say email marketing campaigns are a critical tactic to their success.

20. Mobile devices generate a lot of traffic

About 55% of traffic comes from Internet users who access the web on their smartphones. At the same time, nearly half of them prefer to receive communications from businesses via email.

Related: How to create an effective client onboarding email template

Email trivia

global email phenomenon

21. Too many people check emails too early

The average email user takes some time to warm up before checking messages. However, a whopping 26% of people check email before getting out of bed. Guess email marketers should take this into account when scheduling campaigns. 

22. Think twice before sending an email — it may be legally binding

An email can be considered a legally binding document in many countries, so long as it meets the standard requirements of a contract. This includes countries like Australia, the US, and the UK. 

Related: How to write a new client welcome email

23. Email addresses don’t recognize capital letters

Here’s something most people don’t know — email addresses aren’t case-sensitive. You can write it in capital letters or use lowercase letters and it will still mean the same thing.

24. An email from space

A couple of astronauts, members of the STS-43 Atlantis crew, sent an email from space in 1991. They sent the message to Marsha Ivins, a member of the Johnson Space Center, from the Macintosh Portable.  

This was their message: “Hello Earth! Greetings from the STS-43 Crew. This is the first AppleLink from space. Having a GREAT time, wish you were here,…send cryo and RCS! Hasta la vista, baby,…We’ll be back!”

Note: Some sources disagree about certain parts of the message, but these are the nuances that don’t affect its point.

25. Don’t send emails on Mondays (unless you have to)

A group of researchers who analyzed email errors and subject lines found out that Monday is the worst day for sending emails. Apparently, this is the day when people tend to make more typing errors than they usually do.

Let’s show some appreciation for emails

With that said, it’s clear that the background of electronic mail is much more fruitful and interesting than you might have thought. So the next time your inbox gets crowded with spam, newsletters, and work updates, take a moment to appreciate the incredible journey emails took to become your primary business communication tool.


Drazen Vujovic

Dražen Vujović is a journalist and content writer. More importantly, he is a father of two and a long-distance runner.