chat
expand_more

Spam Emails Are Getting Smarter: What Security Teams Need to Know

Combat spam emails with advanced filtering, user training, and multi-layered, AI-powered defenses.
April 14, 2025

Spam emails aren’t always dangerous, but they’ve evolved beyond annoying ads and inbox clutter. Today, many act as delivery mechanisms for phishing attacks, malware, and other advanced email attacks.

For organizations worldwide, spam emails have become security threats with serious consequences, including:

  • Financial losses from successful phishing attempts

  • Productivity drain as employees navigate deceptive messages

  • IT resource strain from investigation, training, and remediation

  • Risk of data breaches and compliance violations

Modern spam emails use social engineering, AI-generated content, and context-aware messaging to bypass traditional filters. In other words, these aren't obvious scams; they're carefully crafted AI-enabled cyberattacks designed to compromise security.

As spam tactics evolve, basic email filtering no longer offers enough protection. Defending against these threats requires a layered strategy that combines advanced detection with user awareness.

What Are Spam Emails?

Spam emails are unsolicited electronic messages sent in bulk, often for commercial or deceptive purposes. While some spam emails are merely annoying, others can pose serious risks to your employees and organization.

For example, a spam email posing as Amazon customer service can trick employees into sharing sensitive information or clicking a malicious link.

Spam emails come in many forms, each with their own risks. Some common types include:

  • Commercial Advertising: Promotions for products or services you didn’t request

  • Scam-Based Spam Emails: Fraudulent offers like fake lottery wins, inheritance claims, or advance-fee scams

  • Malware Delivery: Messages containing malicious attachments or links

  • Phishing Attempts: Emails impersonating trusted entities to steal credentials or sensitive data

Most spam emails share common red flags, such as:

  • Generic greetings instead of your name

  • Poor grammar and spelling errors

  • Sense of urgency or too-good-to-be-true offers

  • Requests for personal information

  • Suspicious sender addresses

  • Unusual formatting or excessive capitalization

Recognizing these signals is the first step toward reducing exposure and improving your organization’s email security posture.

Spam Emails vs. Scam Emails vs. Phishing

  • Spam emails refer to any unsolicited bulk email, regardless of content.
  • Scam emails are designed to defraud you. Many scam emails are also spam, but their defining feature is the intent to steal.
  • Phishing emails are specialized scams focused on tricking you into revealing sensitive information.

The True Cost of Spam Emails

Spam emails can drain time, resources, and trust. The real costs show up across multiple areas:

Employee Productivity Loss

Employees lose at least two business days per year sorting out external emails. Individually, that may seem manageable. However, scaled across departments, it translates to hundreds or even thousands of lost work hours annually.

This means even seemingly harmless spam emails can waste your employees’ time and create cognitive fatigue, which can divert attention from higher-value tasks and increase the risk of human error.

Operational Burden on IT and Infrastructure

Spam emails place a growing strain on both IT teams and technical infrastructure. Security staff must continuously monitor inbox activity, fine-tune filters, and investigate suspicious messages. These activities consume valuable time and budget.

Meanwhile, the high volume of email traffic increases demand on storage, bandwidth, and computing resources.

Security Breach Expenses

Spam emails can serve as vectors for phishing attacks and malware distribution, leading to potentially costly security breaches.

The global average cost of a data breach reached $4.88 million in 2024. Notably, breaches involving data stored across multiple environments, including public and private clouds, incurred higher costs, averaging over $5 million.

How to Build an Enterprise-Grade Spam Email Defense Strategy

Modern solutions have advanced far beyond simple keyword filters. Using multiple protection layers powered by advanced technologies and educating your employees can help defend your organization against spam emails.

1. Assess Your Organization’s Vulnerability

Assessing your organization’s vulnerability will tell you where you need to bolster your defense strategy.

First, identify all email entry points and map how messages flow across teams. Email entry points include shared inboxes, third-party platforms, and remote endpoints, among others.

Second, audit your existing security policies and compare them to current industry standards. Look for outdated controls, missing enforcement mechanisms, or inconsistent coverage across departments.

Third, pinpoint which types of data attackers would target and determine where that data lives and who has access, utilizing RBAC analytics to monitor access control. High-risk teams like finance, human resources (HR), and legal often sit at the top of the threat surface because they have access to files containing financial records, customer data, and executive communications. Understanding these risks is critical for protecting email data and securing your organization.

Finally, review your organization’s spam-related incident history. Catalog past breaches, phishing attempts, and remediation efforts. Evaluate how well current controls meet regulatory requirements like HIPAA and GDPR.

This risk-focused assessment sets the foundation for a smarter, more targeted defense strategy.

2. Use Enterprise-Grade Detection Technologies

Today’s enterprise-grade detection technologies stop threats before they reach end-users using advanced technologies like AI-powered content filtering and behavioral analysis.

For example, Abnormal uses behavioral AI to baseline normal communication patterns for every user and detect anomalies that traditional filters miss.

AI-powered detection models can analyze large volumes of legitimate and malicious emails to build an understanding of what normal communication looks like. From there, they can identify statistical anomalies, flag suspicious behavior, and adapt to new attack techniques in real time. Some platforms can even analyze images to detect visual phishing attempts that mimic brand logos or UI elements.

Google’s Gmail, for instance, uses TensorFlow-based machine learning to block more than 100 million additional spam messages every day.

But content alone doesn’t tell the whole story.

While content filtering inspects an email’s language, links, attachments, and formatting, behavioral analysis focuses on how the email acts to identify the following:

  • Unusual sending volumes

  • Unexpected attachment types

  • Irregular timing

  • Authentication mismatches

The most effective solutions combine both methods to maximize protection and minimize false positives.

Organizations are investing in AI-driven email security solutions to counter evolving threats.

In addition to a combination of both methods, make sure that the solution you choose integrates seamlessly with existing security infrastructure through:

  1. SIEM Integration: Feeding threat data to Security Information and Event Management systems

  2. Identity and Access Management: Enabling user-specific protections based on role

  3. API Availability: Enabling custom integrations with proprietary systems, perhaps through a hosted API gateway

  4. Threat Intelligence Sharing: Contributing to and consuming threat intelligence feeds

  5. Directory Service Integration: Connecting to Active Directory for policy application

Choose solutions that deliver actionable intelligence and inspect encrypted traffic. After all, a modern spam defense isn’t just about what gets blocked, but how quickly you can respond when something gets through.

3. Implement a Multi-Layered Defense Approach

A strong defense strategy requires multiple layers of protection, each designed to reduce risk at a different point in the email lifecycle. The four layers every enterprise should implement include: perimeter protection, server-level protection, endpoint protection, and user training and awareness.

At the perimeter level, stop threats before they enter your environment by focusing on sender validation and attachment scanning:

  • Block messages from known malicious domains

  • Quarantine suspicious attachments and scan for malware

  • Analyze embedded URLs and look for content patterns associated with phishing

  • Enforce email authentication protocols—like Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting & Conformance (DMARC)—to verify sender identity and prevent spoofing

At the server level, control how messages are processed and filtered internally:

  • Enable rate limiting to slow down bulk senders.

  • Use greylisting to delay or reject emails from unknown sources.

  • Apply sender reputation filtering and custom content rules.

  • Enforce TLS encryption to protect messages in transit.

At the endpoint level, harden user devices and email clients to reduce the blast radius of any threat that slips through:

  • Keep anti-malware solutions updated across all endpoints.

  • Configure email clients to block external content by default.

  • Deploy data loss prevention (DLP) tools to flag sensitive information.

  • Use browser security extensions to help detect phishing pages.

At the user level, reinforce all of the above with consistent training and clear procedures:

  • Provide ongoing security awareness sessions.

  • Run simulated phishing campaigns and offer real-time feedback.

  • Make reporting easy and encourage it through regular reinforcement.

  • Align training content with evolving threat tactics and department-specific risks.

Even with advanced detection technologies in place, some threats will still make it through. That’s why effective spam defense requires a layered approach—one that addresses risk across every stage of the email lifecycle, from initial delivery to user interaction.

4. Build and Optimize a Security Awareness Program

Even the best technical defenses benefit from informed, security-conscious employees. A well-designed security awareness program equips teams to spot threats early, respond effectively, and strengthen the organization’s overall resilience.

Start by tailoring training to different roles. Targeted, relevant content drives better engagement and stronger outcomes:

  • Executives: Focus on business email compromise (BEC) and impersonation threats.

  • Finance Teams: Emphasize payment verification workflows and invoice fraud detection.

  • IT and Security Teams: Dive deeper into technical phishing indicators and emerging tactics.

  • General Employees: Build foundational skills in identifying suspicious messages and reporting them confidently.

Then, use simulated phishing campaigns to reinforce those lessons in real time:

  • Establish a baseline with initial testing.

  • Gradually increase difficulty to match evolving threat tactics.

  • Vary attack types to keep users alert and adaptable.

  • Offer immediate, constructive feedback to reinforce learning.

Finally, create a supportive environment where employees feel confident reporting potential threats. Emphasize education over punishment and make the reporting process clear and accessible.

5. Monitor and Tune Your Spam Defense Posture

Spam defense isn’t a one-and-done effort. Threats evolve quickly, so your strategy needs to evolve with them. Continuous monitoring and regular optimization keep your defenses aligned with both attacker tactics and organizational priorities.

First, monitor key metrics over time to measure impact:

  • Click rates and reporting rates from simulations

  • Time-to-report for both simulated and real incidents

  • Employee confidence levels and knowledge retention

  • Volume of spam reaching end users

  • Volume of user-reported threats and improvements in response time

These metrics provide a baseline for improvement. Use them to identify areas you need to improve, like content filters, employee training, or reporting workflows.

Then, conduct a quarterly review cycle to drive consistent improvements:

  1. Analyze performance metrics across all defense layers.

  2. Identify gaps or high-risk patterns (e.g., rising false negatives, low reporting engagement).

  3. Update technical controls to filter rules, detection thresholds, or integrations.

  4. Refresh user training based on recent threats or simulation results.

  5. Reallocate resources based on team capacity and risk exposure.

Perfect coverage isn’t the goal. Progress is. Even small refinements, applied consistently, strengthen your ability to detect, respond to, and recover from spam-based threats.

6. Create an Incident Response Protocol for Spam Email-Related Breaches

Your layered defenses will deter most spam emails, but not all of them. Some will still reach your employees. A well-defined incident response protocol can help reduce impact, contain malicious activity quickly, and strengthen your security posture going forward.

First, detect and validate the threat. Look for warning signs that often precede or accompany spam-related incidents:

  • Spikes in email volume from similar senders

  • Multiple reports of identical suspicious messages

  • Unusual file types or attachment names

  • Spam clusters targeting specific departments

  • Increases in login attempts tied to recent phishing campaigns

  • Look-alike domains mimicking trusted sources

Confirm the threat by analyzing message headers, payloads, and authentication details. Correlate with SIEM data or user reports where possible.

Then, contain and isolate the threat to begin analysis. When an incident is confirmed:

  • Quarantine the offending messages across all affected mailboxes.

  • Block associated domains and IP addresses at the perimeter.

  • Reset credentials for any users who may have engaged with the message.

  • Isolate compromised endpoints to prevent lateral movement.

  • Preserve message data for forensic review.

  • Document the timeline to support analysis and reporting.

Analyze message headers, inspect payloads in a sandbox environment, and collaborate across teams to coordinate next steps and validate findings.

Lastly, use each incident to improve. After containment, conduct a post-incident review:

  • Identify what went undetected or delayed response.

  • Refine filtering rules or detection models based on new indicators.

  • Strengthen email authentication configurations (SPF, DKIM, DMARC).

  • Deliver targeted retraining to affected users or departments.

  • Share indicators of compromise (IOCs) internally and with trusted partners.

Organizations with defined incident response plans consistently limit the scope and cost of spam-driven breaches.

When incidents occur, Abnormal provides enriched detection data, including sender risk scores, behavioral anomalies, and attack timelines, to support faster triage and forensic analysis.

Building a Resilient Anti-Spam Email Strategy

Protecting your organization from spam-based threats requires a layered, adaptable defense strategy that combines advanced technology with empowered users and well-orchestrated response plans.

Resilient organizations focus on the fundamentals:

  • Deploying advanced filtering powered by AI and machine learning

  • Implementing and enforcing SPF, DKIM, and DMARC authentication protocols

  • Investing in targeted, role-specific security awareness training

  • Aligning defenses with zero-trust principles

  • Continuously monitoring performance and adapting based on threat intelligence

For long-term impact, prioritize high-leverage actions, such as strengthening authentication, fine-tuning detection systems, reinforcing training, formalizing incident response, and committing to ongoing optimization.

Each layer adds resilience. Together, they turn email from a common attack vector into a defensible frontline.

Ready to strengthen your anti-spam defenses? See how Abnormal can help by scheduling a demo today!

Schedule a Demo

See Abnormal in Action

Get a Demo

Get the Latest Email Security Insights

Subscribe to our newsletter to receive updates on the latest attacks and new trends in the email threat landscape.

Discover How It All Works

See How Abnormal AI Protects Humans

Related Posts

B Flux Panel Ecommerce Checkout Hijacking via Phishing
FluxPanel turns legitimate ecommerce checkouts into live data theft operations. Learn how this dark web tool works, the role phishing plays, and how to stop attacks at their source.
Read More
B Fin Serv Attack Trends Blog
Email attacks on financial services rose 25% year-over-year. Learn why FinServ is a top target and how threat actors exploit trust to deceive employees.
Read More
B Flask Phishing Kit
Learn how threat actors used Flask, a popular Python framework, to build a versatile phishing kit for evasive campaigns that bypass traditional defenses.
Read More
B-Trust Trap Social Engineering Blog
The psychology of the modern work environment has become a roadmap for attackers—and a blind spot for traditional email security.
Read More
B VEC Employee Engagement Threat Report Blog 1
New research reveals that employees engage with 44% of read vendor email compromise attacks. See which industries and roles are most vulnerable to this threat.
Read More
B 1500x1500 MKT889c Forrester Wave
Abnormal AI received the highest scores possible in the Innovation and Roadmap criteria, the top score in the Strategy category, and above-average customer feedback.
Read More