Spam Emails: Types and Ways to Block Them

When the internet was taking its first meager steps in 1978, a marketing manager named Gary Thuerk pitched a new computer model to over 400 prospective buyers. He didn’t herd his clients into a massive auditorium to explain the product but sent out an unsolicited email that rewarded the company with nearly $13 million in sales.

Thuerk’s ploy sent out the first “bulk email,” or what we now derisively refer to as spam. This launched an era of explosively growing email attacks from around the globe. By 2003, spam made up roughly 80 percent of email traffic.

That year, the US passed the Controlling the Assault of Non-Solicited Pornography and Marketing (CAN-SPAM) Act. The act set standards determining which commercial messages were spam and allowed people to block others.

The CAN-SPAM Act remains in effect, but email spam is still as strong as twenty years ago.

What Are Spam Emails?

Spam emails are unsolicited emails sent to large numbers of recipients. The CAN-SPAM Act outlines seven rules for messages to avoid being tagged as spam. Sending mass emails without following these regulations can lead to hefty fines of roughly $50,000 for each violation.

The message’s content can be anything from a pet jacket sale to a call to action over unicorn extinctions. It isn’t just emailed; spam can also come from SMS, messenger apps, and social media.

what are spam emails

How is Spam Sent?

Botnets perform most spam attacks since the process is egregiously time-consuming to do manually. Hackers seize control of computers worldwide and control them from a single point. This network of computers gives spammers the processing power to crawl millions of websites for random email addresses and compile a distribution list.

Next, the botnet simultaneously sends the spam email to every collected email address. Spammer’s expectations are low because their messages are easy to snuff out. The attack succeeds if just a few out of a hundred thousand recipients fall for their trick.

Email providers and security programs are getting better at detecting incoming spam. However, in an endless cycle, this is causing spammers to develop new strategies to get around email filters.

Snowshoe Spam

Email filters measure the reputation of senders to determine who can reach your inbox. If an address has a history of sending mass emails, it’s more likely to get flagged for spam.

Snowshoe spamming gets around this feature by sending messages from multiple IP addresses. This is possible because the botnet has infected devices from many locations. So, an infected computer in Texas can send a couple hundred emails, while computers in London, Beijing, and Moscow send the rest. This method diffuses the harmful damage accrued from sending mass emails, like how a snowshoe disperses a person’s weight.

Blank Email Spam

Blank email attacks showcase the dangers of even opening up a suspicious email. These messages are empty and are primarily used for identifying active or high-priority targets. Botnets have tools for detecting when an email is opened, and it informs the spammer of more susceptible or less defended people.

Image Spam

Image spam avoids detection by formatting the text into an image. Spam filters work by flagging keywords in the text, but they can’t read pictures. Spammers create a graphic that includes their desired message that is only readable by human eyes.

New OCR (Optical Character Recognition) programs are coming out that automatically scan the text on images. However, these programs struggle to read custom fonts and handwriting and require a large amount of processing power from your device.

Why Do People Send Spam Emails?

Every website and their neighbor are asking for your email address these days. Legitimate businesses use machine learning to identify each person’s tastes and what they respond well to. Overall, this is a far more successful method for drumming up sales.

So, why do some people rely on spamming to get your attention?

Fighting Brand Loyalty

The biggest reason for spam marketing is that the spammers can’t compete with the more recognizable names. The Global Banking and Finance Review found that 71 percent of people prefer products from a brand they already know. Fighting against brand loyalty is expensive and time-consuming, and spammers would rather trick customers into interacting with them.

Spreading Malware

Clicking on unknown links from spam emails is an excellent way to ruin your computer and possibly damage your life. Phishing attacks are social engineering attacks designed to trick people into revealing personal or sensitive information.

Like spam, common phishing attacks have a low chance of success, so scammers send mass emails to increase their odds.

Economic Viability

Once you’ve collected an email list, sending spam emails costs next to nothing. You aren’t spending money analyzing individual customers or creating custom experiences for specific demographics. Instead, spam marketers embrace the low-cost, low-reward mindset.

The same is true from the cyber threats side of the issue. Scammers send mass emails because it’s the cheapest way to find easy marks.

How to Stop Spam Emails

All of the top email providers include spam filters. Yahoo looks for blocked IP addresses, negative reputations, and direct user reports. Gmail’s filter taps into the company’s database of dangerous sites and keywords to decide. Because Google collects so much data, its spam filter is highly effective.

However, these built-in protections aren’t enough to weed out all spam. If they were, you’d never see a spam email. Spammers know how service providers detect spam and design their emails to get around each provider’s security. Put simply; spammers know their enemy.

Using a third-party spam filter to patch up weak points in your provider’s defenses is best. Spammers won’t know precisely how you defend yourself and are less likely to choose a method that gets around the extra filter. There are free and paid options for this.

Free systems aren’t as customizable and should be saved for personal use. We strongly encourage business owners to equip devices with enterprise-level filters, as ransomware and cyber threats can cost millions to resolve.

Some other tips for staying safe are:

  • Consistently deleting spam messages that get through without opening them. This signals to spammers that you aren’t an active target and may remove you from their email list.
  • If you notice spam getting through, you can add words from the email subject line to your spam filter.
  • Use email masking to keep your primary address out of spammer’s reach. This is when you sign up for other services with an auto-generated email that forwards messages to your primary inbox.


Even if you avoid the first nine spam emails, falling for the tenth can still hurt you. Opening spam can lead to identity theft and financial fraud in the worst cases. Avoiding the risk and keeping spam out of your inbox altogether is best.

Spammers are good at hiding who’s sending you an email. It may be necessary to run an email lookup if you need to identify and block a specific source. Check out RecordsFinder’s collection of guides that teach you how to keep you and your business safe online!