The Business Email Security Blog

What is Spam? A Brief History of Unwanted Email

As one of the most common means of communication today, our email inbox is a target to many online advertisers and scammers. From shady offers of lifestyle products to fake notifications of inheritance, our junk folders are filled with dozens of unwanted emails every day.

It is estimated that 85% of all email is spam. According to Statista, 88.88 billion out of 105.67 billion of emails sent daily in September 2021 were spam. The total number of emails reached a record high in July, 2021 with 336.41 billion daily email on average. The percent of spam emails was also around 85% and this has been a consistent trend for months and years.

While modern email filters use advanced technologies to direct unsolicited emails to our junk folders, a lot of them still ends up in our inbox. Most of these emails can be easily identified as spam, but there are those that are more sophisticated and can easily trick online users into clicking phishing links and sharing sensitive data.

To help you recognize spam email and protect from potential threat, this article will look into the brief history of spam and provide online safety best practices.

What is Spam?

Spam is most frequently associated with email but can also be sent via social media and text messages. By definition, it is any type of digital communication that is unwanted or unsolicited regardless of the channel through which it is sent. Spam emails and messages are often sent in bulk, usually with a purpose to promote goods or services of dubious origin and quality.

Besides these relatively harmless but highly annoying ads, there are different types of scam emails looking to trick you into revealing your personal data to hackers. Due to their increasingly sophisticated nature, scam emails may not always be easy to identify, and this is why they are serious threats in the online world.

The Origin of the Term

An interesting fact about today’s use of the word spam in the context of emails is that it stems from the Monty Python’s Flying Circus TV series. In one of the episodes, the word was used to describe the ubiquity of canned meat products known as SPAM on the menu. Although the show was released in 1972, it was not until 1993 that the word was first used to refer to an unsolicited email.

The First Spam Email

The history of spam emails can be tracked to 1978, when the first commercial ad was sent to 400 users of ARPANET. At the time, the total number of users on the network was 2,600, meaning that this email reached 15% of the global online population.

The email was sent by Digital Equipment Corp. marketer Gary Thuerk, who saw this as an opportunity to promote his company’s computer products. All ARPANET users at the time were listed in a physical directory and Thuerk’s team used that as a source list. Although there were some responses, the impression was mainly negative, and the email was found to violate Arpanet’s Acceptable Use Policy.

Spam became a real problem in the 1990s and 2000s, when all email servers became open relay, meaning that messages could be sent to any recipient from any sender. The volume of web content grew, and link farms started being used for web search results manipulation. This is also the time when spam filters were first developed.

In 2003, CAN-SPAM Act (Controlling the Assault of Non-Solicited Pornography and Marketing Act of 2003) was passed in the U.S. with an aim to regulate commercial email sending practices.

Types of Spam Today

When we talk about spam today, we typically refer to one of the four most common types:

  1. Unsolicited ads. The most widespread type of spam are unsolicited ads for different products and services, usually promoting better lifestyle through weight loss pills, medications, etc.
  2. Phishing and spoofing emails. The goal of these emails is to trick online users into sharing their personal data. Both types of emails try to impersonate someone you know (a friend, your bank, etc) inviting you to share your password, credit card details, and other sensitive information.
  3. Hoaxes and scams. These are probably the easiest to identify as there are certain types of scams that have been around for years. One of the most common examples is an email coming from an African prince looking to give away his fortune.
  4. Adult content spam. With limited space to advertise in mainstream online media, adult content providers often turn to spam to promote their products and services. These usually include erotic content or products that people may feel uncomfortable buying in person.

How Spam Filters Work

From the standpoint of our mailing systems, spam is characterized by several properties that indicate their nature. In recent years, spam filtering technologies have been significantly improved and often rely on machine learning to decipher the message and its intent.

Typically, the first thing that spam filters look into is the message header, as it may contain various trigger words. Furthermore, it also contains mail server info which the filter will evaluate as safe or illegitimate. The reputation of the source from which the message is sent is another indicator of a potentially harmful email.

There is a complex mechanism working on the back end of email communications, but they are not always able to filter out all our unwanted messages. One of the reasons for this is the fact that spammers are using more sophisticated systems to mask their messages and break through the known filtering mechanisms.

Spam Email Protection Best Practices

Eliminating spam completely is hardly possible, but there are ways to make sure you do not get scammed. You can stay safe by practicing the following:

  • Never give out personal information to unknown email contacts
  • Never click links in emails sent by unknown persons or in a suspicious format
  • Never respond to emails you are not sure where they originate from
  • Use anti-virus software to protect from possible threats in links and attachments

While end users can protect from spam by strengthening their filters or simply deleting emails from suspicious senders, website owners must find other ways to fight spam. There are multiple systems that can help them keep their website safe and ensure great experience. These include:

  • Always use the latest version of your Content Management System (CMS)
  • Regularly update plugins
  • Use strong SMTP-level protection
  • Limit the login attempts to your website
  • Use plugins to prevent bot submissions on forms
  • Limit and block IP addresses
  • Set up email filters in cPanel

Read our blog for additional tips on how to secure your email server from spam.


The ubiquity of spam emails makes it a global problem that everyone online must learn to live with. Most Internet users are able to identify and ignore spam messages, but the threat is constantly evolving and we must keep getting informed about it to make sure it does not impact our lives or online privacy. By following the tips outlined above, you can protect yourself and your website from this type of threat.

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