What is Spam Email - Types & How to Prevent Spam Emails?
- by Brittany Day
If you are an email user, chances are you’ve experienced the aggravation and decreased productivity associated with spam email. But are you aware that spam email that reaches your inbox can have potentially serious consequences for you and your business?
What is Spam Email?
Spam email, or junk email, refers to unsolicited messages sent in bulk. This notorious email threat got its name from Spam lunch meat, which has a reputation of being ubiquitous, repetitive and unavoidable. According to Statista, spam messages accounted for an alarming 56% of email traffic in March 2019. Although statistics show that spammers only receive one reply for every 12,500,000 emails sent, spam email remains a profitable business model due to the astronomically large number of phony messages sent per day.
The majority of spam email is commercial in nature, and since the expense of a phony message is borne mainly by the recipient, spam can be viewed as postage due advertising.
Regardless of its purpose or origin, spam email should be recognized as a serious threat. Aside from the fact that it is extremely annoying, spam may contain malicious links or attachments and is often a vector for other serious attacks like phishing and malware.
History of Spam Email
Although the first spam email was sent in 1978 to several hundred users on ARPANET, email spam emerged as a serious problem in the 1990s when commercial use of the Internet became possible. As the Internet gained popularity, spam email became increasingly unavoidable and profitable for attackers. Since the early 1990s, the prominence of spam email steadily grew until 2014, at which point it was estimated that spam email accounted for roughly 90% of all email messages sent.
In 1996, anti-spam activists recognized the serious problem that spam email had become, and began taking action to combat it. That year Dave Rand and Paul Vixie, two well-known software engineers, founded the Mail Abuse Prevention System (MAPS). The organization’s mission was to pioneer anti-spam techniques. MAPS collected a list of malicious IP addresses, which became known as the Real-time Blackhole List (RBL), and used this list to block unwanted emails.
In 2001, the SpamAssassin spam-filtering platform was first uploaded to SourceForge by creator Justin Mason. At the time, spam email was becoming increasingly problematic and no real tools existed to effectively combat it. The open-source project, which analyzes and scores emails based on how strongly they resemble either spam or non-spam, experienced rapid growth and evolution in its early years. In 2004, SpamAssassin become an Apache Software Foundation project. Eighteen years later, SpamAssassin is still an extremely popular spam filtration platform, and the framework is a key element of many email security solutions.
Spammers’ Methods - Types of Spam Email
Crafting a spam email campaign is relatively easy and straightforward, and research shows that spam earns senders approximately $7,000 per day. Criminals typically utilize similar methods to bombard users with unsolicited email, which include:
- Email address harvesting: In order to send out unsolicited emails, spammers must first collect the email addresses of the intended recipients. It is common for them to purchase or trade lists of email addresses from other spammers. In some cases, spammers utilize special software known as "harvesting bots" or "harvesters", which scour the Internet to obtain email addresses from public data. Attackers will sometimes launch directory harvest attacks, in which valid email addresses at a specific domain are found by guessing the email address using common usernames in email addresses at that domain. A final tactic that spammers employ for email address harvesting is offering a product or a service free of charge as long as the user provides a valid email address. Attackers then use these addresses as spam targets for future campaigns.
- Obfuscating message content: To defeat spam filters that operate by searching for patterns in the subjects or bodies of messages, spammers will often intentionally misspell commonly filtered words or insert other characters to make it more difficult for filter software to identify their messages. These changes are often small and subtle, making spammers’ messages readable to humans but unlikely to be recognized by computer programs.
- Defeating Bayesian filters: Bayesian filtering, which works by correlating the use of tokens (which are typically words), with spam and non-spam emails and then using Bayes' theorem to calculate the probability that an email is or is not spam, has become a popular spam-filtering technique. Naturally, attackers have developed methods to weaken this type of spam filtering. To defeat Bayesian filters, some spammers now include irrelevant, random words to manipulate word probabilities in a technique known as Bayesian poisoning.
- Spam-support services: Various online activities and business practices, known as spam-support services, are believed to support spammers’ efforts and allow their operations to continue. Spam-support services include processing orders for goods advertised in spam, hosting Web sites or DNS records referenced in spam messages, bulk-friendly hosting, DNS blacklists and the production of spamware.
How to Recognize Spam Email:
While it is blatantly obvious that certain emails are spam, some spammers craft highly deceptive messages that are difficult to differentiate from legitimate emails. Here are some best practices for identifying spam email that users should engage in to avoid falling from spammers’ dangerous scams:
- Look for unknown, suspicious or spoofed email addresses. Pay attention to the sender’s email address, especially if a message seems strange or suspicious. Attackers often use spoofed email addresses to deceive recipients.
- Be wary of unfamiliar links or strange attachments. Refrain from clicking on links or downloading files in emails unless you trust the source. Malware, viruses, and other types of malicious material can be easily downloaded through malicious attachments or links.
- Look for misspelled words or added characters within the subject or body of an email. Spammers often intentionally misspell words or insert additional characters within their messages to evade spam filtration software. Be cautious of emails that contain spelling and/or grammatical errors.
- Think before you respond: watch for offers or opportunities that seem too good to be true. If the content in an email seems too good to be true, it likely is! Such emails are often phishing scams trying to steal credentials or other sensitive information. Remember to never give out personal information such as passwords, social security numbers, or credit card numbers via email. Legitimate businesses will never ask for it, and sharing sensitive data can result in significant losses and, in some cases, identity theft.
If you suspect that a message is phony, don’t forget that replying to spam or attempting to “unsubscribe” comes with its own set of risks! Play it safe and don’t reply at all if you are unsure about an email.
How to Prevent Spam Email from Reaching the Inbox:
While spam filtration technology is an important element of any spam protection strategy, this software is most effective when it is implemented as part of a comprehensive, multi-layered cloud email security solution.
Defense in depth in critical in effectively securing email accounts. No single layer of technology is sufficient in protecting against spam email and other email threats. Look for a comprehensive cloud email security solution with multiple layers of protection which work harmoniously to prevent spam and other types of malicious emails from reaching the inbox.
How Guardian Digital Can Help:
Guardian Digital EnGarde Cloud Email Security, the premier open-source cloud email security solution, provides complete, highly effective protection against spam email and the other dangerous attack variations that constitute today’s email threat landscape. Benefits of securing your business email with EnGarde include:
- Fully-managed, end-to-end control of your email, preventing malicious messages from reaching the inbox
- Multi-layered architecture, where individual layers of security work in concert to provide comprehensive, resilient protection
- Secure endpoint encryption using strong cryptography
- Multiple leading antivirus engines and spam filtration technologies, including the Apache SpamAssassin scoring framework
- Tighter security, adaptive implementation and eliminated risk of vendor lock-in through the use of a transparent, collaborative development approach
- Centrally managed cloud-based administration
- Unparalleled 24x7x365 customer support, conveniently providing you with the peace of mind to focus on aspects of running your business other than email security
Want to learn more about spam email and how to protect against it?
Do you have any questions about spam email and spam protection that haven’t been addressed in this article? If so, please contact us and we would love to answer them!
Stay tuned for our next Email Threats Explained blog post: What are Viruses?
- Effectively Securing Business Email Accounts: Are Employees the Weakest Link?
- Encryption: An Essential Yet Highly Controversial Component of Digital Security
- Business Email Security Redefined: Key Benefits of Securing Your Business Email with Guardian Digital
- 8 Business Email Security Best Practices
- Demystifying Email Encryption: Stop Sender Fraud
- Demystifying Phishing Attacks: How to Protect Yourself Now
- Demystifying Tax Fraud: How to Avoid Falling Victim to Deceptive, Costly Scams This Tax Season
- Coronavirus Phishing Scams are On the Rise - Is Your Business Email at Risk of Infection?
- Dave Wreski: Founder of Guardian Digital – Open Source Cloud Email Security
- New Ransomware Warnings: Is Your Business Safe from This Silent Threat?
- FBI: Existing Cloud Email Protection Inadequate Against Phishing, Ransomware
- Email Risk is Universal: Securing Business Email in Every Industry Sector
- How To Safely Navigate Office 365 While Working Remotely
- Tips and Advice for Staying Safe Online During COVID-19
- Why Your Business Needs Better Email Security
- Defending Against COVID Email Spoofing Attacks with DMARC
- You’ve Got Mail: How To Tell If It’s Fraud
- Open-Source Security Is Opening Eyes
- Think Like A Criminal: How To Write A Phishing Email
- The Four Biggest Email Threats Your Business Faces Today
- Everything On DocuSign Phishing Attacks in 3 Minutes
- Understanding Payload-Less Email Attacks in Under 3 Minutes
- Demystifying Fileless Malware in Less than 3 Minutes
- How to Protect Sensitive Data & Maintain Client Trust in Financial Services Industry
- Exchange Servers Are Vulnerable - Learn How To Secure Your Email Server Now
- Apache SpamAssassin Leads A Growing List of Open-Source Projects Taking Steps to Correct Instances of Racism and White Privilege
- Cyber Risk Is Greater than Ever in the Legal Industry
- Understanding Malicious URL Protection - And Why You Need It to Secure Your Email
- Email Security for SMBs Beyond COVID-19
- Email Risk Is BIG for SMBs - How To Protect Your Business Now
- Email Threats By The Numbers: How Big Is My Risk?
- The Modern Email Threat Landscape: Where Traditional Defenses Fall Short
- Why Email Security Is More Important Than Ever in This 'New Reality'
- The Threat of CEO Fraud Extends Beyond the C-Suite
- Top Email Security Trends Putting Your Business at Risk of Attack
- Think Like A Criminal: What You Need to Know About Social Engineering Attacks in 2020
- Managed Services: A Key Element of Effective Email Security that Even Modern Solutions Lack
- How To Secure Your Remote Workforce: Advice from Leading Security Experts
- FBI: The 2020 Presidential Election Is Under Attack by Email Scammers
- AT&T Security Researchers Identify a Correlation between Strong Cybersecurity and Business Success
- The Aftermath of a Cyberattack Pt. 1: Phishing Recovery Basics
- It Pays to be Prepared! Ransomware Preparedness & Recovery Basics
- Breaking Down Fileless Malware: Anatomy of an Attack
- Office 365 Email Is Vulnerable to Attack Without These Critical Supplementary Defenses in Place
- Your Current Approach to Email Security May Not Be Enough
- Ways to Prevent Email Account being compromised in a Breach
- Celebrating 20 Years of Revolutionizing Digital Security
- IBM Closes its $34 Billion Acquisition of Red Hat
- Interview with Security Expert and Author Ira Winkler
- What is Phishing Email? How to prevent Phishing email scams?
- Ways Our Business Email Exceed Your Expectations
- Spear Phishing Protection - Definition & How To Recognize Spear Phishing Email
- What is Whaling (Whaling Phishing)? & How to Prevent Whaling attacks?
- Ransomware Attack Explained - Best Practices For Ransomware Protection
- Business Email Compromise (BEC) - Definition & Prevention From BEC Attacks
- Wire Transfer Scams Involving Real Estate Transactions: How to Prevent Fraud with Effective Email Security
- Guardian Digital and Mautic: A Dynamic Open-Source Duo
- Email Malware - How to Recognize & Prevent Malware Email Attack
- An Open-Source Success Story: Apache SpamAssassin Celebrates 18 Years of Effectively Combating Spam Email
- What is Spam Email - Types & How to Prevent Spam Emails?
- Email Virus - Complete Guide to Email Viruses Plus Best Practices
- What Is A Zero-Day Attack & How To Prevent Zero Day Exploit?
- 2020: A New Decade of Digital Threats - Is Your Business Email Secure?
- Linux: An OS Capable of Effectively Meeting the US Government’s Security Needs Heading into 2020
- Email Security: Complete Guide on Email Protection & Types of Email Threats
- Guardian Digital Keeps its Customers Protected from Intel Design Flaw
- Security Spotlight: Open Source Email Security Solutions
- Top Six Advantages of Open Source Development/Products
- Python and Bash - Contenders for the most used scripting language
- Guardian Digital Outlines Top 4 Benefits of Choosing Cloud
- Unrivaled Protection Against Today’s Most Dangerous Threats
- Guard Your Email Accounts Against Today’s Most Dangerous Threats
- Security Highlights from Defcon 26
- Linux / Open Source FAQs: Common Myths / Misconceptions
- Email Security FAQs Answered by Guardian Digital
- Guardian Digital Mail Systems: Designed to be Secure Without Fail