Email Security

What Is Email Security?

Email remains the #1 attack vector for cybercriminals. Over 90% of cyberattacks begin with a phishing email. Email security encompasses the tools, technologies, and practices that protect organizations from email-borne threats and prevent sensitive data from leaving via email.

Email Threat Landscape

| Threat | Description | Impact | |---|---|---| | Phishing | Deceptive emails that trick users into revealing credentials or clicking malicious links | Credential theft, malware delivery | | Business Email Compromise (BEC) | Impersonation of executives or vendors to request fraudulent payments | Financial fraud (avg. $125K per incident) | | Malware/Ransomware | Malicious attachments or links that deliver malware | System compromise, data encryption | | Account Takeover | Compromised email accounts used for internal phishing | Lateral movement, data theft | | Data Exfiltration | Sensitive data sent to unauthorized external recipients | Data breach, compliance violations |

Email Security Architecture

Modern email security uses multiple layers:

1. Secure Email Gateway (SEG)

Traditional approach: inspect all inbound/outbound email at the gateway. Scan attachments, check URLs, filter spam. Deployed as MX record or inline with Microsoft 365/Google Workspace.

2. API-Based / Cloud Email Security

Modern approach: integrate directly with Microsoft 365 or Google Workspace via API. Analyze emails post-delivery using AI/NLP to detect sophisticated threats that bypass gateways. Can remediate threats already in mailboxes.

3. Security Awareness Training

Human layer: train employees to recognize and report phishing attempts.

SEG vs. API-Based Email Security

| Aspect | SEG | API-Based | |---|---|---| | Deployment | MX record change | API connection | | Analysis timing | Pre-delivery | Post-delivery (with clawback) | | Internal email visibility | Limited | Yes | | AI/NLP detection | Some | Core strength | | Legacy support | Better | Cloud email only |

Many organizations now use both: a gateway for basic filtering plus an API-based solution for advanced threat detection.

Leading Email Security Vendors

Major providers include Proofpoint, Mimecast, Abnormal Security, Microsoft Defender for Office 365, Barracuda Email Security, Cisco Secure Email, Ironscales, Tessian, and Trend Micro Email Security.