Best Email Encryption Tools

AppRiver is an email security vendor now operating under OpenText Cybersecurity after its acquisition by Zix and then OpenText. In the email-security scope, it is known for cloud-delivered filtering, phishing and malware blocking, and encrypted message delivery for organizations that want to protect Microsoft 365 and other email environments without deploying on-premises appliances. Its portfolio also includes adjacent compliance functions such as archiving and continuity, but the core buyer is typically a small-to-mid-sized business or managed service provider looking for managed email protection and encryption.

Enable secure and compliant email communication without adding friction. Make it easy for your teams, customers, and partners to work securely and prevent data leaks using encrypted email and simplified DLP policies.

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LuxSci is a secure healthcare communications vendor whose email security offerings center on HIPAA-compliant message protection, policy-based encryption, and compliant delivery for organizations handling PHI. In the email-security scope, it is best known for secure high-volume transactional email, gateway-based encryption for Microsoft 365 and Google Workspace, and secure email hosting with auditability. It is aimed at healthcare providers, payers, digital health companies, and other regulated organizations that need encrypted email without sacrificing delivery at scale.

Mailprotector designs, builds, and supports products that help organizations secure and optimize email.

OpenText Core EDR provides endpoint detection and response integrated with SIEM, SOAR, and vulnerability assessment in a single cloud platform. It deploys a lightweight agent for telemetry collection on endpoints including laptops, servers, and mobile devices, capturing process execution, file changes, network connections, and registry modifications. Built for MSPs managing SMB clients, it uses pre-configured policies, automated playbooks for containment like device isolation and process termination, and CVE-based vulnerability scanning. Global threat intelligence and syslog/API integrations with IT, security, and PSA systems enable multi-client visibility and response without additional vendors.

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Proofpoint is a human-centric cybersecurity platform focused on protecting organizations from email-based and identity-driven attacks such as phishing, business email compromise (BEC), and social engineering. It secures inbound and outbound communications using advanced threat detection, AI-driven impersonation analysis, URL and attachment sandboxing, and behavioral risk signals. Beyond email protection, it extends into data loss prevention (DLP), insider threat detection, and security awareness training to reduce human risk across the organization. The platform integrates across email, cloud applications, and collaboration tools to protect sensitive data and stop attacks targeting users.

Retarus Secure Email Platform is a cloud-based secure email gateway focused on protecting business email traffic from spam, phishing, malware, BEC, spoofing, and malicious links. It is positioned as a modular email security service for organizations that want gateway-based filtering with data-sovereignty controls and support for complex email infrastructures. Retarus also extends into adjacent areas such as email continuity and transactional email delivery, but its Email Security scope centers on inbound and outbound protection and remediation for enterprise mail environments.

Trustwave MailMarshal is an email security gateway focused on filtering inbound and outbound mail for phishing, malware, spam, ransomware, business email compromise, and data leakage. It is positioned for organizations that want layered controls, policy enforcement, and deployment flexibility across on-premises, cloud, hybrid, and Microsoft 365 environments. Trustwave and LevelBlue describe it as a long-established product used by enterprises, government organizations, and service providers that need centralized email threat filtering and auditability rather than a lightweight inbox add-on.