Mimecast Data Leak Prevention

Mimecast Data Leak Prevention is a cloud-managed email DLP service for organizations that need centralized control over sensitive outbound messages. It suits security and compliance teams governing Microsoft 365, Google Workspace, on-premises, or hybrid mail. The main trade-off is clear: it offers extensive email policy handling, but not endpoint, removable-media, cloud-app, or data-discovery controls.

Overview

Mimecast scans messages and attachments to detect accidental or malicious leakage. Its scope covers headers, subject lines, body text, HTML, attachments, text patterns, words, and inappropriate images. Policies can use keywords, dictionaries, file hashes, and pattern matching, giving administrators several ways to distinguish sensitive content from routine correspondence.

Management is centralized in a web console, with granular rules assigned to users or groups. That is a practical fit for organizations whose departments have different handling requirements. It also makes policy design the critical operational task: the service can enforce only the rules administrators create.

Key features

When a policy triggers, administrators can block the message, hold it for review, copy it to a group, deliver it through Secure Messaging, or append content such as a disclaimer. Those choices let teams balance protection with business continuity instead of blocking every flagged message. External recipients can receive sensitive information through the Secure Messaging portal, while policy-based TLS encryption protects email in transit.

Mimecast can remove hidden Microsoft Word metadata, including comments and tracked changes, before delivery. That is a focused safeguard against accidentally exposing document history. The product integrates with Microsoft Exchange and Office 365, and supports Microsoft 365, Google Workspace, on-premises, and hybrid email environments.

Its wider cloud platform includes risk scoring, incident workflows, phishing detection, malware scanning, attachment scanning, user-and-admin quarantine access, outbound filtering, impersonation protection, malware sandboxing, legal hold, eDiscovery, journal capture, search and export, case management, insider-risk workflows, and data-exfiltration detection. Mimecast also describes six data sources, email simulation, campaign automation, landing-page building, and training content. These capabilities broaden the surrounding email-security and awareness picture, but they do not turn the DLP component into endpoint or cloud-app data protection: endpoint controls, cloud-app controls, removable-media control, and data discovery are absent.

Mimecast says its policies can support PCI-DSS, HIPAA, and GLBA work. Its Trust Center lists ISO/IEC 27001:2022, ISO/IEC 27701:2019, SOC 2 Type 2, HIPAA, and other attestations. Customers can use a knowledge base, community, or support case for assistance.

Pricing

Mimecast uses paid, custom pricing, with no free plan or published numeric price and no stated billing term for this DLP product. Requesting a quote is therefore necessary before comparing total cost.

Mimecast’s plans page identifies Advanced as custom pricing, but does not publish a numeric price or billing term. The listed detector count is one for Professional, Enterprise, and Gov, so larger or more complex deployments should confirm capacity and any additional charges.

Platforms

Deployment is cloud-based through a cloud gateway. Supported mail environments include Microsoft 365, Google Workspace, on-premises email, and hybrid deployments. The product is presented as web-managed rather than as endpoint software.

Who it's for

Mimecast is a strong match for organizations that treat email as a primary leakage route and need centralized policy enforcement, review queues, controlled external sharing, and compliance support. It is especially relevant to teams already operating Microsoft or Mimecast-centered mail infrastructure. Look elsewhere if your requirement is broad data discovery, endpoint enforcement, removable-media restrictions, or direct cloud-application controls.

Pros and cons

Pros

• Scans message fields, attachments, patterns, dictionaries, hashes, and images, supporting varied detection policies.
• Offers several responses to a trigger, including review, secure delivery, copying, and disclaimers, rather than only blocking.
• Supports Microsoft 365, Google Workspace, on-premises, and hybrid email with centralized administration.
• Secure Messaging, TLS encryption, and Word-metadata removal address common risks in external sharing.
• Risk scoring, incident workflows, eDiscovery, legal hold, and case management support broader investigations.

Cons

• No endpoint controls, cloud-app controls, removable-media control, or data discovery, limiting it as a general-purpose DLP platform.
• All pricing is custom, so budgeting requires a sales conversation.
• Professional and Gov list only 30 days of historical activity, which is less investigative context than Enterprise’s 90 days.
• Policy effectiveness depends on administrators defining accurate rules for each user and group.

Alternatives

Choose Cyberhaven Insider Risk Management when you need coverage across API, browser extension, Linux, macOS, web, and Windows environments rather than an email gateway alone.

DTEX Insider Risk Management is another paid option spanning Linux, macOS, web, and Windows, with pricing handled through a demo request.

FortiDLP fits teams seeking endpoint-oriented plans, although each listed tier has a 100-endpoint minimum.

NetClean ProActive provides a paid alternative across API, web, and Windows.

Behavox Falcon is a paid API and web option with commercial terms discussed with sales.

Red Vector FULCRUM offers paid API and web deployment.

SATARK is a free API and Linux alternative.

Varonis Data Discovery and Classification is better suited when discovery and classification across Linux, self-hosted, and web environments are central, with quote-based pricing.

For broader category comparisons, see Data Loss Prevention Software, Insider Risk Management Software, Email Security Gateways, Email Archiving Software, Email Anti-Spam Software, and Phishing Simulation Software.

Verdict

Choose Mimecast Data Leak Prevention if your priority is centrally governed email DLP with flexible policy actions, secure external delivery, and compliance-oriented controls across mixed mail environments. Look elsewhere when protection must extend to endpoints, cloud applications, removable media, or enterprise-wide data discovery, or when you need transparent pricing.