Glossary of Email Security Terms

Whether you’re new to email security or expanding your knowledge, this glossary provides straightforward definitions of commonly used email security terminology. From phishing and encryption to compliance, it explains the threats your organization faces and the solutions that protect against them.

You’ll find terms covering email threats (phishing, business email compromise, malicious attachments), protection technologies (secure email gateways, DLP, encryption), security services (managed detection and response, account takeover protection), and compliance considerations for regulated industries.

In this glossary, you’ll learn:

• How different email threats work and what protection methods defend against them
• What key email security technologies are and why they matter for your organization
• Essential compliance and data protection concepts for regulated industries
• Common acronyms and terms used when evaluating email security platforms

Account Takeover Protection (ATP)

Account Takeover Protection (ATP) is a security technology that monitors user behavior patterns and login activity to detect anomalies such as unusual locations, impossible travel, or credential misuse. It can identify and block unauthorized access attempts before compromised email accounts can be exploited.

Business Email Compromise (BEC)

Business Email Compromise (BEC) is a highly targeted cyberattack where criminals impersonate executives, trusted vendors, or business partners and manipulate employees into authorizing fraudulent wire transfers, sharing login credentials, or disclosing sensitive company information.

Cloud Email Security

A remotely managed approach where cloud email security protects organizations from phishing, malware, spam, and account compromise without requiring on-premises hardware or complex infrastructure changes.

Data Loss Prevention (DLP)

Technology that monitors outbound email and identifies sensitive information like financial records, health data, or confidential documents to prevent data loss by blocking or encrypting messages before they leave the organization.

Email Archiving

The automated process of capturing and securely storing email communications in a searchable repository ensures organizations can meet compliance requirements, respond to legal discovery requests, and maintain long-term business records through email archiving systems.

Email Compliance

Policies, controls, and tools that help organizations meet regulatory and legal requirements, such as HIPAA, GDPR, or SEC regulations, by ensuring proper handling, retention, and protection of email communications across the business.

This table summarizes key email regulations, their target organizations, and the severe penalties for non-compliance:

Regulation	Applies To	Penalties for Non-Compliance
HIPAA (Health Insurance Portability and Accountability Act)	Healthcare providers, health plans, healthcare clearinghouses, and their business associates in the U.S.	Fines range from $100 to $50,000 per violation, up to $2 million per year for repeated violations; potential criminal charges
GDPR (General Data Protection Regulation)	Any organization that processes personal data of EU residents, regardless of where the organization is located	Fines up to €20 million or 4% of annual global revenue, whichever is higher
SEC Regulations (Securities and Exchange Commission)	Publicly traded companies, broker-dealers, investment advisors, and financial services firms in the U.S.	Fines, sanctions, trading suspensions, and potential criminal prosecution for willful violations
FINRA (Financial Industry Regulatory Authority)	Brokerage firms and registered representatives in the U.S.	Fines ranging from thousands to millions of dollars; suspension or revocation of licenses
SOX (Sarbanes-Oxley Act)	Publicly traded companies in the U.S. and their accounting firms	Fines up to $2 million; imprisonment up to 20 years for executives who knowingly destroy or falsify records

Disclaimer: Compliance requirements are subject to change. Always consult the official regulatory websites and legal counsel for the most current requirements applicable to your organization.

Email Encryption

The process of scrambling email content into unreadable code that only authorized recipients with the proper decryption key can access. Email encryption protects sensitive messages from interception during transmission and unauthorized access.

Email Filtering

The automated scanning and sorting of incoming and outgoing email to identify and block threats, spam, and policy violations, with email filtering rules applied in real-time before messages reach user inboxes or leave the organization.

Email Managed Detection and Response (EMDR)

A managed security service where experts continuously monitor email systems to identify suspicious activity, investigate potential threats like account compromise or targeted attacks, and help organizations respond to advanced email threats that bypass traditional filtering.

Email Security

The practice of protecting email systems, accounts, and communications from cyber threats, including phishing, malware, spoofing, business email compromise, and data leaks, through a combination of email security technologies and policies.

Email Security Platform

A unified solution that consolidates multiple email protection capabilities, including threat detection, encryption, data loss prevention, and compliance automation, so organizations can manage all aspects of email security from a single email security platform rather than deploying separate point solutions.

Email Threat Protection

Security controls that analyze incoming messages to detect and block email threats such as phishing attempts, malicious links and attachments, spoofing, and impersonation before they reach users’ inboxes.

Security Control	Detection Mechanism	Threats Blocked with Example
Phishing Detection	URL reputation scanning, NLP for suspicious phrasing, sender behavior analysis	Phishing with urgent fake login pages, e.g., “bank-login[.]secure-site[.]com” emails blocked pre-inbox
Malicious Attachment/Link Scanning	Sandbox detonation, signature hashing, heuristic analysis	Ransomware .exe in ZIPs (e.g., Emotet) or drive-by links quarantined after failed sandbox execution
Spoofing Prevention	SPF/DKIM/DMARC domain authentication	Domain spoofing, like fake “support@yourbank.com,” is rejected on DMARC failure
Impersonation Detection	ML on executive patterns, anomaly in display names	BEC CEO fraud from “ceo@company[.]org” flagged for style/recipient mismatches

Inbound Email Security

Security controls that analyze incoming messages before they reach user inboxes, screening for phishing attempts, malicious attachments, malware, spam, and spoofed senders to block external threats from entering the organization.

Managed Security Service Provider (MSSP)

A third-party company that delivers outsourced security monitoring, threat detection, and incident response services to organizations, with many MSSPs offering specialized email security management as part of their protection portfolio.

Managed Service Provider (MSP)

A third-party company that remotely manages and monitors IT infrastructure and security services for client organizations, with many MSPs offering email security deployment, configuration, and ongoing support as part of their managed services portfolio.

Malicious Attachment Protection

Security capability that analyzes email attachments using sandboxing, signature detection, and behavioral analysis to identify and block malicious attachments containing malware, ransomware, viruses, or other harmful code before they reach users’ inboxes.

Microsoft 365 Email Security

Additional security layers that complement native Microsoft 365 protections by adding advanced threat detection, enhanced encryption, and data loss prevention capabilities to strengthen email security beyond built-in Microsoft defenses.

Outbound Email Security

Protection that monitors and scans outgoing messages to detect and prevent data leaks, policy violations, and unauthorized sharing of sensitive information before outbound email leaves the organization.

Patented One-Click Encryption

An encryption method that allows users to secure sensitive email with a single click, eliminating complex steps like certificate management or recipient portals and enabling patented one-click encryption without requiring technical expertise or changes to normal email workflows.

Phishing Protection

Security technology that analyzes incoming emails for signs of phishing attacks, such as spoofed sender addresses, malicious links, or social engineering tactics, and blocks fraudulent messages designed to steal credentials, financial information, or sensitive data.

Ransomware Protection

Email security controls that detect and block malicious attachments, links, and messages designed to deliver ransomware, preventing these attacks from reaching users’ inboxes and encrypting critical business data.

Secure Email Gateway (SEG)

A security layer positioned between the email server and the internet that filters inbound and outbound email traffic, blocking spam, malware, phishing attempts, and other email-borne threats before they reach users or leave the organization.

Secure Email for Healthcare

A security layer positioned between the email server and the internet that filters inbound and outbound email traffic, blocking spam, malware, phishing attempts, and other email-borne threats before they reach users or leave the organization.

Secure Email for Legal

Email security and encryption solutions tailored to protect attorney-client communications, case files, and confidential legal documents, helping law firms and legal departments maintain privilege and meet professional responsibility requirements for secure email for legal practices.

Security Awareness Training

Employee education programs that teach staff to identify and report phishing emails, social engineering tactics, suspicious links, and other email-based threats, helping reduce human error as a security risk through ongoing security awareness training.

Spam Filtering

The automated process of identifying and blocking unwanted or unsolicited email messages based on content patterns, sender reputation, and known spam signatures, preventing these messages from reaching users’ inboxes.

SaaS Email Security

Cloud-based email protection delivered as software-as-a-service, enabling organizations to deploy and manage security capabilities through SaaS email security platforms without requiring on-premises hardware or complex infrastructure.

Feature	Email Analyzer	URL Defanger	SPF Checker
Primary Purpose	Analyzes full email headers for routing & delivery insights	Defangs suspicious URLs for safe threat sharing	Validates SPF records for domain authentication
Key Analysis	Message ID, journey, destination, return path, routing issues	URL structure (bypasses spam/reputation filters)	Syntax, policy, risks, allowed IPs, MX records
Security Value	Detects internal delivery problems & anomalies	Enables secure investigation without blocking	Prevents spoofing & unauthorized mail servers
Ideal Use Case	Troubleshooting bounced/failed emails	Sharing malicious links with security teams	Pre-deployment domain config checks

Zero-Trust Email Security

A security approach that assumes no email, sender, or user is trustworthy by default and requires continuous verification of every message and access attempt through zero-trust email security policies, behavioral analysis, and authentication checks before allowing delivery or access.