Email Security: 19 Tools compared

Abnormal AI, known as Abnormal Security until April 2025, is an AI-native email security platform that uses behavioral AI to detect and block socially-engineered email attacks that bypass traditional email security gateways. Rather than relying on signatures, threat feeds, or URL scanning, Abnormal builds behavioral profiles of every identity in the organization and detects anomalies in communication patterns, writing style, and email metadata. This approach is particularly effective against business email compromise, vendor fraud, and account takeover attacks that contain no malicious payloads for traditional tools to catch.

Cisco Secure Email (formerly Cisco Email Security Appliance / IronPort) is an enterprise email security gateway that provides protection against phishing, malware, ransomware, and business email compromise. As part of Cisco's broader security portfolio, it integrates with Cisco SecureX, Talos threat intelligence, and Cisco's network security products to provide cross-domain threat visibility. Cisco Secure Email is available as a cloud-hosted service or on-premises appliance and is particularly strong in organizations that have standardized on Cisco networking and security infrastructure.

Egress provides intelligent email security that combines adaptive encryption with AI-powered risk detection. Rather than applying blanket encryption rules, Egress analyzes each email's content, recipients, and context to dynamically determine the right level of protection. From automatic TLS to full end-to-end encryption. Now part of KnowBe4, Egress signs BAAs for HIPAA compliance and is widely used in healthcare, legal, and financial services.

LuxSci provides HIPAA-compliant email hosting and encryption as a combined service, eliminating the need for separate email and encryption vendors. It offers multiple encryption methods. TLS, portal pickup, PGP, and S/MIME. With policy-based automation that selects the right method per message. LuxSci signs BAAs and provides dedicated infrastructure for healthcare organizations that need both email hosting and encryption under one HIPAA-compliant umbrella.

Microsoft Defender for Office 365 is Microsoft's native email security solution that provides protection against phishing, malware, and business email compromise for Microsoft 365 environments. It integrates deeply with the Microsoft security ecosystem including Microsoft Sentinel, Defender XDR, and Entra ID to provide cross-domain threat detection and automated investigation. For organizations heavily invested in Microsoft 365, Defender for Office 365 offers strong protection without requiring a third-party email security gateway.

Paubox is a HIPAA-compliant email encryption platform purpose-built for healthcare organizations. It encrypts every outbound email by default using TLS with automatic fallback to a secure portal, so recipients read messages in their normal inbox without passwords or portals. Paubox is HITRUST CSF certified and signs BAAs, making it the go-to choice for hospitals, health systems, and medical practices that need frictionless HIPAA-compliant email.

Proton Mail Business provides zero-access end-to-end encrypted email hosted in Switzerland under some of the world's strongest privacy laws. Messages are encrypted on-device before reaching Proton's servers, meaning even Proton cannot read your email. For HIPAA-covered entities, Proton signs BAAs on its Business and Enterprise plans. The platform includes a full suite of privacy tools including Proton Calendar, Drive, and VPN.

Trend Micro Email Security is a cloud-hosted email gateway that protects against phishing, BEC, ransomware, and advanced malware targeting email channels. Part of Trend Micro's broader Vision One platform, it leverages Trend Micro's extensive global threat intelligence network and integrates with XDR capabilities for cross-layer detection. Its Writing Style DNA technology uses AI to detect BEC attacks by analyzing the writing patterns of executives and flagging emails that deviate from established styles.

veriBIMI is a brokerage and professional service for brands implementing BIMI. The services page lists a DMARC and email infrastructure audit covering DMARC, SPF and DKIM configuration, preparation of the W3C SVG Tiny P/S logo file via the related makeBIMI tool, Verified Mark Certificate brokerage including trademark verification, Common Mark Certificate brokerage for brands without registered trademarks, and DNS deployment of the certificate. The site states it works with Entrust or DigiCert as the issuing certificate authority and that its managed process targets three to four weeks against an unassisted average of six to twelve weeks. Published fees are EUR 299 for the audit, EUR 799 plus CA fee for the CMC package and EUR 1,499 plus CA fee for the VMC package. The founder page names Simon Baertschi as builder of makeBIMI and veriBIMI. The privacy policy places infrastructure in Geneva, Switzerland and disputes in the Canton of Geneva, and the footer names Infomaniak Network SA as host; no legal entity name, registration number or address is published.

Zix, now part of OpenText, is one of the longest-established email encryption platforms with a massive install base across healthcare, finance, and government. Zix provides policy-based encryption that automatically secures emails containing sensitive data, using TLS and a secure portal fallback. Its ZixDirectory enables direct encrypted delivery between Zix customers without portal friction. Zix signs BAAs and meets HIPAA, PCI DSS, and SOX requirements.