Email Security

The stakes have never been higher for email security. Remote work has expanded attack surfaces, while cyber criminals have grown more advanced social engineering tactics. Further escalated by AI-enabled cyber-attacks, the magnitude of email-based threats has reached unprecedented levels.

Proofpoint research reveals that 99% of organisations were targeted for account takeovers, with 62% experiencing at least one successful compromise. Meanwhile, business email compromise (BEC) attacks continue to surge, with Proofpoint detecting and blocking an average of 66 million BEC attempts per month throughout 2024. These numbers reflect a stark reality that every CISO and IT leader faces daily.

Email security is the framework of technologies, protocols, and policies designed to protect email communications from cyber threats while maintaining message confidentiality, integrity, and availability.

Modern email security platforms deploy multi-layered defence mechanisms that combine traditional signature-based detection with advanced behavioural analytics and machine learning (ML) algorithms. These systems prevent unauthorised access resulting in data breaches, detect and block malicious content, and ensure the privacy of sensitive information being transmitted.

Email remains the predominant attack vector for cyber criminals, who increasingly exploit it to spread malware and viruses, steal sensitive data, deploy ransomware and phishing attacks, and manipulate users into divulging confidential information. Advanced persistent threats now leverage generative AI to craft highly personalised spear-phishing campaigns that bypass traditional rule-based filters. Email security solutions are designed to protect against the ever-evolving spectrum of email-borne attack vectors, including human error.

Email attacks often start with actors gathering information about their targets through public sources or social engineering techniques. Modern attackers use AI to automate reconnaissance and build target profiles from social media, LinkedIn, and public repositories. Once they’ve gained the necessary data and insights, they craft convincing emails or launch technical exploits to access email accounts.

This intelligence gathering now feeds directly into AI-powered attack generation. Today, 82% of phishing emails incorporate AI-generated content, achieving 54% click-through rates versus 12% for traditional phishing. Beyond text, attackers deploy deepfake voice technology to impersonate executives—30% of organisations fell victim to these AI-enhanced voice scams in 2024.

Credential theft drives most email account takeovers. Once an attacker gains access, they use the compromised email account to launch further attacks, exfiltrate sensitive data, or impersonate the account owner to commit fraud. Contemporary attacks employ polymorphic techniques that continuously modify email content and URLs to evade signature-based detection systems.

Email security is important because it has become a business-critical imperative as cyber threats reach unprecedented scale and sophistication. Email is widely known as the number-one threat vector for cyber-attacks. Meanwhile, cyber criminals are increasingly tweaking their tactics and techniques to exploit email vulnerabilities, with AI-powered attacks affecting about seven in eight organisations in the past year.

Modern email security delivers proven ROI through both cost savings and operational efficiency. Key benefits include:

• Delivers substantial cost savings and ROI: Organisations implementing comprehensive email security solutions achieve significant financial returns, with case studies showing annual savings of $243,000 through vendor consolidation and reduced incident response costs. The global email security market’s projected growth from $5.17 billion in 2024 to $13.22 billion by 2032 reflects the proven value organisations receive from these investments.
• Protects against phishing and spoofing attacks: Email security systems detect and resolve email threats such as phishing and spoofing, leading to devastating breaches and the risk of malware or other harmful computer viruses.
• Minimises attacker dwell time: Advanced platforms reduce the time attackers remain undetected in systems, limiting their ability to escalate privileges, move laterally, or exfiltrate sensitive data. Shorter dwell times result in lower incident costs, faster recovery times, and reduced regulatory exposure.
• Prevents data breaches: Advanced email encryption helps prevent costly data breaches. It safeguards confidential information such as credit card numbers, bank accounts, employee PII, trade secrets, and intellectual property.
• Enhances detection and user training: Human-centric security combines behavioural analytics with targeted training to improve phishing detection and user threat recognition.
• Strengthens compliance posture: Email security ensures regulatory compliance for data protection and breach notification, with reduced dwell time demonstrating effective controls to auditors.
• Real-time protection: Today’s leading solutions can provide real-time protection against zero-day exploits by providing anti-malware and anti-spam protection.
• Avoids compromised accounts and identity theft: Email encryption ensures that only the intended recipients can access the email content. In turn, this can help avoid compromised accounts and identity theft by preventing attackers from stealing login credentials and other personal data or installing malware.

People-centric protection has become the most critical component of email security strategy. Modern email security involves more than just using technologies to detect threats and safeguard data. “Human error contributed to 95% of data breaches in 2024, driven by insider threats, credential misuse, and user-driven errors,” reports James Coker at Infosecurity Magazine. Despite this reality, only 73% of employees are aware of their organisation’s email security policies, and just 52% follow them consistently.

Malicious intent lies at the core of all email attacks, regardless of their form or function. To help you stay informed and protected, here are some common types of email attacks:

• Phishing: Attackers use social engineering to impersonate trusted sources and trick individuals into clicking links or downloading attachments, often by tailoring emails to specific recipients using details scraped from public data. AI-enhanced spear phishing campaigns can modify content and sender details on the fly to evade detection and increase success rates. These attacks increasingly bypass legacy filters and blend into everyday communication, making vigilance essential.
• Ransomware: Malicious software that encrypts files or systems until a ransom is paid. Ransomware attacks generally begin with an email containing a malicious link or file attachment. Once opened, the ransomware is downloaded and executed, encrypting the user’s files and demanding payment for the decryption key.
• Malware: Software designed to infiltrate and damage computer systems without the user’s consent. Email is a common attack vector for distributing malware, typically through attachments or links. Once installed, malware can carry out a host of malicious activities like stealing data, monitoring user activity, or providing remote access to the attacker.
• Email spoofing: Attackers forge email addresses or mimic well-known brands to make their messages appear authentic, often as part of business email compromise or credential theft schemes. These brand impersonation tactics use convincing names, logos, and domain lookalikes to trick recipients into clicking malicious links, submitting sensitive data, or following fraudulent instructions. Together, they exploit both technical gaps and human trust, making them especially effective and difficult to spot.
• Man-in-the-Middle attacks (also known as Adversary-in-the-middle attacks): An attacker intercepts communication between two parties and can read, modify, or inject messages. This can involve intercepting emails in transit, enabling attackers to alter the content or redirect the communication. Man-in-the-middle attacks are frequently used to steal sensitive information, manipulate transactions, or distribute malware.
• Data exfiltration: A targeted type of email attack where an attacker steals sensitive data from an organisation’s email system. Data exfiltration often involves accessing email accounts to extract confidential information, such as intellectual property, financial data, or personal information. These threats can be challenging to detect, as cyber-attackers often use discreet methods to avoid triggering security alerts.
• Denial of service: Attackers crash email servers by sending a high volume of emails that the servers are eventually unable to handle. This type of cyber-attack can severely disrupt email communications, resulting in operational delays and preventing legitimate emails from being delivered. Denial of service attacks can be part of a larger attack strategy to distract cybersecurity teams while executing other fraudulent activities.
• Account takeover: Attackers access an individual’s email account and use it to send spam or phishing emails or access sensitive data. Account takeovers often stem from other threats like phishing attacks, credential stuffing, or exploiting weak passwords. Once an attacker gains access to an email account, they can impersonate the account owner, escalate privileges, spread malware, or steal sensitive information.
• Identity theft: An attacker steals an individual’s personal information, such as their name, address, or social security number, and uses it for fraudulent purposes. Email is a popular vector for identity theft activities, with attackers using phishing or social engineering tactics to deceive victims into divulging personal information. The stolen data can then be used to carry out financial fraud, open new accounts, or conduct other illegal activities.

Understanding these types of attacks empowers you to recognise and avoid them, keeping your email domains and data safe.

AI-enhanced email security flips the equation. Instead of waiting for known attack signatures, these platforms harness ML to analyse context, anomalies, and language patterns in real time. The result? Higher detection rates, more accurate alerting, and the ability to spot brand-new attack methods before users ever see them. AI-driven solutions adapt and learn continuously, helping organisations keep pace with threats that evolve hour by hour.

Human-centric security recognises that people are both the greatest vulnerability and strongest defence in cybersecurity. This approach integrates user-friendly tools with existing workflows, provides contextual guidance, and delivers targeted training against threats like phishing. Rather than treating employees as risks, it empowers them as active defenders.

Effective human-centric email security requires coordinated action across organisational roles:

• Employees serve as the frontline sensors, equipped with behavioural training to recognise and report advanced threats that bypass technical filters.
• CISOs provide strategic oversight, aligning human risk management with business objectives while establishing metrics that track behavioural improvements alongside traditional security indicators.
• IT directors implement role-based security experiences, deploying contextual nudges and just-in-time training modules that integrate directly into daily workflows without disrupting productivity.
• Security engineers build the technical infrastructure that supports analytics and creates adaptive systems that learn from user interactions and provide real-time feedback to strengthen decision-making across all organisational levels.

“Human risk is difficult to tackle as we all work across email, collaboration apps, the cloud, and the web, creating threat risk, identity sprawl, and data exposure in new ways,” notes Sumit Dhawan, CEO of Proofpoint. “Proofpoint pioneered human-centric security, and now we’re redefining it by bringing together previously disparate processes and technologies into one unified platform to protect new digital channels, reduce risk for organisations, and better guide users in real-time, every day,” Dhawan adds.

Even advanced technical defences fail when users make uninformed decisions. Employees who understand why security practices matter—not just what to do—become the organisation’s strongest defence against email threats.

Today’s email security leverages AI technologies like natural language processing, behavioural analysis, and computer vision to detect threats that bypass traditional filters. Machine learning builds user profiles and instantly flags emails that break normal patterns, processing millions of messages per second while continuously improving.

The key is balancing automation with human oversight. Automated systems quarantine obvious threats and block malicious URLs in milliseconds, but elaborate attacks require human analysts for final decisions.

Proofpoint’s AI-powered detection demonstrates scale and accuracy, processing trillions of threat intelligence data points to minimise false positives and manual workload for security teams.

This blend of machine-speed processing and human strategic oversight transforms email security from reactive defence to proactive threat hunting, keeping pace with evolving attacks.

Email security implementation demands different approaches for CISOs, IT directors, and engineers, each facing role-specific challenges and priorities.

CISOs: Strategic Leadership and Risk Communication

Your primary challenge involves translating technical email security metrics into business language that resonates with board members and executive leadership. SEC cybersecurity rules now require material incident disclosure within four business days, making email security failures a direct compliance risk with board-level implications.

According to Patrick Joyce, global resident CISO at Proofpoint, “As GenAI adoption accelerates both opportunity and threat, CISOs are being asked to do more with less, navigate unprecedented complexity, and still safeguard what matters most. It’s clear that the role of the CISO has never been more pivotal—or more pressured.”

Frame your email security investments as risk mitigation tools that protect against regulatory penalties, litigation costs, and brand damage. Board reporting should emphasise trend analysis rather than point-in-time metrics. Show how email threat volumes are changing over time and how your defences are adapting accordingly. This demonstrates proactive risk management rather than reactive incident response.

IT Directors: Operational Excellence and Vendor Management

Your focus centres on system integration and operational efficiency across multiple security platforms. Email security cannot operate in isolation from your broader security stack. Vendor consolidation represents a significant opportunity, with organisations using integrated email security platforms reporting up to $243,000 in annual savings through reduced complexity and streamlined incident response processes.

New platforms require comprehensive staff training and change management. Teams need clear escalation procedures and response playbooks covering both automated and manual interventions.

Engineers: Technical Optimisation and Alert Management

Alert fatigue poses one of the biggest challenges in email security operations. Current AI-powered platforms process millions of emails daily while generating manageable alert volumes for human analysts. Focus on tuning detection sensitivity to minimise false positives while maintaining comprehensive threat coverage.

Email security platforms must integrate with multiple detection systems, adding complexity. Standardise alerts and response procedures across platforms to reduce analyst cognitive load. Use automated playbooks for routine threats while escalating complex cases to human analysts.

Email attachments remain a prime attack vector for threat actors who disguise malware as legitimate documents, compressed folders, HTML files, or executables. Once opened, these malicious attachments deliver viruses, ransomware, spyware, and other malware designed to exfiltrate data or compromise systems.

Recent examples include the March 2024 Agent Tesla campaign, where attackers disguised malware as bank payment notices in archive file attachments, successfully bypassing antivirus defences to steal sensitive data and keystrokes from victims.

Similarly, the StrelaStealer attacks of 2024 affected over 100 organisations across the EU and the United States through convincing spam emails with attachments that delivered credential-stealing malware, targeting finance, government, and manufacturing sectors by simply changing file formats to evade detection.

Email security demands a methodical approach combining technology, training, and continuous testing. Basic spam filters no longer suffice—today’s threats require comprehensive, adaptive defences.

Step 1: Implement Zero Trust Email Architecture

Start with the assumption that no email can be trusted by default. Every message requires verification before it reaches the user’s inbox. Configure SPF, DKIM, and DMARC authentication protocols to reject emails that fail verification checks.

Segment email infrastructure by user role and data sensitivity, with extra protection for high-value targets like executives and finance teams. This containment approach minimises breach impact.

Step 2: Deploy AI-Powered Threat Detection

Current email security platforms use machine learning to analyse behavioural patterns and content anomalies in real time, processing millions of emails daily while catching threats that signature-based filters miss.

Deploy sandboxing for suspicious attachments and URL rewriting for links. With AI engines detonate potential malware in safe environments before delivery, stopping zero-day exploits and polymorphic threats.

Step 3: Enforce Multifactor Authentication

Require MFA for all email access, especially privileged accounts. Combine something users know with something they have or something they are. Even compromised passwords become useless without additional verification factors.

Integrate email logins with your identity provider and single sign-on solution. Conditional access rules can require device compliance or location verification for remote access attempts.

Step 4: Establish Continuous Security Testing

Run regular phishing simulations that mirror current attack trends using personalised, role-based scenarios. Track click-through and credential submission rates to identify high-risk individuals.

Conduct quarterly red team exercises, testing your entire email security stack. Professional attackers using real-world techniques expose gaps that automated testing misses, maintaining defensive readiness.

Step 5: Enable Real-Time Threat Intelligence and Data Loss Prevention (DLP)

Activate continuous email monitoring using live threat intelligence feeds and automated threat hunting. These tools baseline user behaviour, flagging anomalies and suspicious patterns for immediate investigation, while also scanning all outbound emails for sensitive content like financial or confidential data.

Set up DLP policies and approval workflows so risky messages can be blocked, encrypted, or escalated. This ensures your organisation catches both inbound threats and potential data leaks as they occur.

Step 6: Establish Frictionless Reporting

Deploy one-click reporting mechanisms that let users flag suspicious emails directly from their inboxes. Simplified reporting boosts employee participation and enables faster threat containment.

Create feedback loops informing users about report outcomes. This reinforcement sustains vigilance and builds organisational security awareness.

Organisations following this systematic approach see significant improvements in threat detection speed and security posture. Success requires combining automated defences with human intelligence while maintaining operational efficiency.

Organisations can strengthen email security by embedding human-based principles into existing protocols through three key strategies:

• Behavioural analytics: AI-driven systems like Proofpoint Nexus® monitor email interactions—such as login patterns, attachment handling, and communication anomalies—to identify risky behaviours. These tools prioritise high-risk users (e.g., executives or finance teams) for targeted interventions, reducing incident rates by up to 80%.
• Adaptive training: Personalised phishing simulations and micro-learning modules improve threat recognition. Training programs adapting to user roles, regional threat trends, and past vulnerabilities see faster behavioural change than generic courses. Real-time feedback loops, such as in-the-moment alerts when users hover over suspicious links, reinforce secure decision-making.
• Frictionless reporting: Simplified reporting mechanisms, like one-click options to flag suspicious emails directly from inboxes, increase employee participation in threat detection. Organisations using such systems report a significant rise in incident reporting, enabling faster threat containment.

Security platforms like those offered by Proofpoint exemplify this approach, combining behavioural analytics with role-based training to address both technical and human vulnerabilities. By aligning security measures with natural workflows and cognitive biases—rather than relying solely on technical controls—organisations reduce reliance on user perfection while fostering a proactive security culture.

Proofpoint leads the field in email security by combining robust AI-enhanced detection with people-centric protection that consistently turns metrics into outcomes. Our platform scans trillions of emails and messages daily, achieving a 99.99% detection rate and removing weaponized emails post-delivery—before anyone can click or engage. This approach delivers unmatched visibility into the human attack surface and streamlines threat remediation, helping customers reduce incident response costs and manual workload.

Independent analyst reports rank Proofpoint highest in four out of five critical email security use cases, highlighting our effectiveness in core protection, outbound controls, security integration, and operational efficiency. By combining advanced anomaly detection, adaptive controls, and intuitive reporting tools, organisations empower employees and security teams to stay ahead of evolving threats. The result is a security posture proven to mitigate risk, protect sensitive data, and maintain business continuity—even against complex, AI-powered attacks. To learn more about how to bolster your email security and protect against today’s threats, contact Proofpoint.