Today’s Top Email Security Threats—And How to Fight Back

In today’s digital world, email marketing stands out as a powerful and cost-effective channel. It helps businesses foster customer relationships, deliver targeted messages, boost brand recognition, drive website traffic, and ultimately, increase sales. However, the reliance on customer data also makes email marketing a prime target for cybercriminals. 

As we approach the holiday season, with its surge in online activity and email volume, email security should be even more top-of-mind for marketers. Cybercriminals often ramp up their efforts during this period, looking to exploit vulnerabilities and capitalize on increased consumer engagement. 

This blog post will shed light on these threats and equip you with the tools to fight back. 

Is email even secure? 

Despite its (young) age and minimal changes to its core protocol, SMTP (the language spoken by email servers) remains the backbone of email communication, handling over 350 billion emails daily. Its widespread adoption and ease of use make it a trusted method for sharing messages and files. However, this openness also leaves it vulnerable to abuse. 

Just as websites must handle incoming traffic, email servers have to deal with a lot of incoming messages. Not to mention that email security threats depend on human interaction—we are often the targets! So, it’s understandable that mailbox providers actively filter out potentially malicious content. 

This has also led to the development of various defense mechanisms, including anti-spam algorithms that can sometimes misclassify legitimate promotional emails. By understanding the threats discussed here, you can refine your email marketing strategy. You’ll learn to navigate the complexities of email security, ensuring your bulk emails reach their intended recipients and that you appear as a legitimate marketer to mailbox providers, not a cybercriminal. 

Protecting against email list poisoning 

Let’s start with a threat that often flies under the radar of most marketers: list poisoning. It’s a sneaky tactic where malicious actors—competitors, disgruntled individuals, or even cybercriminals—inject invalid or fake email addresses into your legitimate mailing list. They might do this manually through sign-up forms or unleash automated scripts to flood your list with bogus addresses. 

Their goal? To sabotage your email marketing efforts. By inflating your list with invalid addresses, they trigger higher bounce rates and spam complaints. This can land your emails in the spam folder or even get you blocked by mailbox providers (MBPs). The fallout? Significant operational headaches and difficulty gauging the true effectiveness of your campaigns. 

We all know email marketers constantly strive to reach as many people as possible. But list poisoning throws a wrench in those efforts. Identifying and cleaning up a poisoned list can be challenging, and the damage, if not addressed quickly, can linger. 

So, how do you fight back? Fortify your sign-up forms with CAPTCHAs or honeypots—hidden fields that only bots will fill out. Validate every email address entered, ensuring it’s real and won’t harm your sender reputation. 

Most importantly, adopt best practices like double opt-in. This ensures that only genuinely interested subscribers receive your future emails, keeping your list healthy and engaged. 

Risk of email data breaches  

Email marketers, by the nature of their work, collect and store vast amounts of personal data. Cybercriminals actively target email marketers’ accounts to gain access to valuable mailing lists. Once in, they can wreak havoc by sending malicious emails on behalf of the company. This not only results in a loss of control over communications but can also severely tarnish the brand’s image. 

Reports reveal that 88 percent of data breaches start as an employee mistake. Even more alarming is that 37 percent of these breaches occur due to employees mistakenly sending sensitive data to the wrong recipient. This highlights the critical need for comprehensive employee training and heightened security awareness. 

Companies must proactively prepare for potential breaches. This involves establishing dedicated incident response teams, developing clear procedures, and conducting regular drills to ensure a swift and effective response in the event of a breach. 

Implementing robust security measures is equally essential. Employ role-based access controls to limit who can access sensitive data, and mandate multi-factor authentication (MFA) to add an extra layer of security to accounts. Additionally, managing vendor risks through thorough assessments and contractual safeguards further strengthens your breach preparedness. 

Phishing attacks and spoofing 

Did you know that 91 percent of cyberattacks begin with phishing emails? These deceptive messages trick users into revealing sensitive information or clicking on malicious links, paving the way for data breaches and compromised accounts. 

Phishing attacks can take various forms. Spear phishing, for instance, targets specific individuals or organizations with highly personalized and convincing content. On the other hand, attackers may cast a wider net, sending mass emails with more generic content to a large number of recipients. Some phishing attacks include fake alerts or notifications from well-known companies, urging recipients to click on malicious links or attachments. 

These strategies exploit our trust and prey on our inability to distinguish legitimate messages from fraudulent ones. Beyond an email’s “From” address, we often rely on visual cues within the email, which are easily forged. AI, particularly generative AI tools, allows attackers to create highly convincing phishing emails. These messages can mimic the tone, style, and vocabulary of trusted individuals or organizations, eliminating common errors that might give away a scam. 

If a brand hasn’t secured its domains with proper email authentication protocols, it becomes vulnerable to domain spoofing—where attackers falsify the sender’s identity. To protect your brand from domain misuse in phishing attacks, it’s crucial to implement robust email authentication protocols like SPF, DKIM, and DMARC. Without these measures, your legitimate emails may be rejected or filtered as spam. 

Malware and ransomware 

Emails serve as a primary weapon for distributing malware, including viruses and ransomware. A staggering 94 percent of malware infiltrates systems through email, often disguised as harmless attachments or links that unsuspecting users click. 

This is why we advise against using URL shortening services. These tools can obscure malicious links, making it easier for attackers to spread malware and potentially trigger spam filters in mailbox providers. 

Compromised email systems become breeding grounds for malware distribution, and lead to devastating data breaches, shattered customer trust, and hefty financial losses. Hackers can inject malicious code into email templates, transforming innocent marketing campaigns into vehicles for widespread infection. Ransomware attacks, where cybercriminals encrypt your data and demand payment for its release, are increasingly targeting email lists and CRM systems. 

Since many malware and ransomware attacks masquerade as legitimate brands, preventing spoofing attempts is critical. Ensure that only your authorized servers send your emails. 

Maintaining the integrity of your outgoing emails is how you stay safe in the game against these cyber criminals. Validity Sender Certification offers 24/7 monitoring, backed by a dedicated compliance team that actively scans your email programs for threats that could jeopardize your deliverability. 

Scams, spam, and affiliate marketing 

The internet is bursting with scams. We hesitate before sharing personal or financial details on unfamiliar websites, and for good reason. Email often serves as the launching pad for these scams, from the more obvious phishing attempts mimicking a brand’s identity to more subtle tactics like the Business Email Compromise (BEC) scam, which targets businesses by impersonating executives or vendors. Even tech giants like Meta and Google have fallen prey, losing millions. 

These scams have fueled the development of content-based filtering and spam reporting technologies. Speaking of spam, let’s define it: Spam is any unsolicited email.

Consent is key. If subscribers aren’t clear on what they’re signing up for, even legitimate marketing emails can trigger spam complaints, impacting your deliverability and reputation. 

While legitimate, affiliate email marketing occupies a gray area. Some affiliates resort to deceptive tactics like spoofing domains or misrepresenting the brand, leading to increased spam complaints and damaging the brand’s reputation. Google emphasizes the importance of responsible affiliate marketing practices in its bulk sender policy, along with the need for transparency, consent, and adherence to best practices. 

Beyond the threats 

The bottom line: Email threats like list poisoning, data breaches, phishing, spoofing, malware, and ransomware erode trust and damage your brand’s reputation. Customers expect a safe and secure experience, and falling victim to these threats leads to disengagement and churn. 

To maintain a strong sender reputation, prioritize email marketing best practices. Send relevant content only to subscribers who have explicitly opted in. Ignoring these principles will severely impact your email deliverability. 

If you’re unsure about your email security or need help navigating deliverability challenges, explore Validity’s email solutions. Our tools and expertise can help you protect your brand and achieve email marketing success.

Or, contact our Professional Services team today to turn data into actionable strategies.