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Cybersecurity · head to head

Diligent vs Mimecast

Diligent logo

Diligent

Cybersecurity

Board management and enterprise GRC platform assembled from Galvanize, Steele and Diligent Boards

From
On request
Rated
-
Mimecast logo

Mimecast

Cybersecurity

Email and collaboration security

From
$4/month
Rated
-

The short version

  • Each has a real cost: Diligent the platform is an assembly of acquisitions, with the analytics engine from ACL, risk from Rsam, ethics and third-party diligence from Steele and the board portal from Diligent itself, so cross-module reporting and consistent user experience should be tested in a proof of concept rather than assumed.; Mimecast no pricing is published for any product or plan, and every route ends at a quote or demo request
  • They diverge on capability: Diligent covers Diligent Boards, Mimecast covers Advanced threat detection.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which Diligent and Mimecast actually diverge.

Attributes where Diligent and Mimecast differ
AttributeDiligentMimecast
Starting priceOn request$4/month
Pricing modelquotesubscription
PlatformsWeb, iOS, Android, WindowsEmail, Cloud, Collaboration
FoundedUnknown2003

Identical on both: free tier (No), user rating (Not yet rated), category (Cybersecurity).

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Diligent

  • Diligent Boards
  • Entity management
  • Audit and analytics
  • Risk management
  • Third-party risk
  • Ethics and compliance
  • ESG and sustainability
  • Market intelligence

Only in Mimecast

  • Advanced threat detection
  • Secure sharing
  • Email encryption
  • Message tracking
  • Email archiving
  • Legal hold
  • eDiscovery
  • Backup and recovery

What people use each for

The jobs each tool is most often brought in to do.

Diligent

  • A listed company that wants board papers, entity records and the audit committee reporting pack produced from one governance systemnot Mimecast
  • An internal audit function moving from sampling to full-population transaction testing using the ACL heritage analytics enginenot Mimecast
  • A regulated firm consolidating a whistleblower hotline, third-party due diligence and policy attestation after an enforcement findingnot Mimecast
  • A group needing sustainability disclosure data collected with the same audit trail and controls as financial reportingnot Mimecast

Mimecast

  • Email security filtering against phishing and targeted attacksnot Diligent
  • Email archiving, continuity and compliance for organisationsnot Diligent

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Diligent

  • The platform is an assembly of acquisitions, with the analytics engine from ACL, risk from Rsam, ethics and third-party diligence from Steele and the board portal from Diligent itself, so cross-module reporting and consistent user experience should be tested in a proof of concept rather than assumed.
  • Pricing is unpublished and consistently at the top of the market, and organisations that need only one capability, a board portal or an audit analytics tool, generally pay less and get more from a specialist.
  • Renewal leverage is weak once the board portal is embedded, because directors are the least willing user group to be migrated and that dependency is well understood by the vendor at renewal time.
  • The analytics engine expects real data skills, and audit teams without an analytics-capable member typically use a fraction of what they licensed while paying for all of it.
  • Module-by-module implementation means the promised single view of governance and risk usually arrives years after the first purchase, if the later modules are ever funded.

Mimecast

  • No pricing is published for any product or plan, and every route ends at a quote or demo request
  • The platform is split into separately sold products for email security, awareness training, data protection and governance
  • Collaboration threat protection, DMARC analysis, incident response and email archiving are all further add ons on top of those

Pricing, plan by plan

Diligent

On request
  • Diligent One Platform$undefined/year
    • Quoted by module and user count
    • Board portal seats priced separately from GRC modules
    • Annual subscription, commonly multi-year

Mimecast

$4/month
  • Defender$4/month
    • Per user
    • Threat protection
    • Impersonation prevention
  • Archive$3/month
    • Email archiving
    • Legal hold
    • Search & recall
  • Unified$6/month
    • All Defender features
    • All Archive features
    • Backup

Which should you pick?

Choose Diligent if

  • You need diligent boards.
  • You work on Web, iOS, Android, Windows.
  • You also want entity management.

Choose Mimecast if

  • You need advanced threat detection.
  • You work on Email, Cloud, Collaboration.
  • You also want secure sharing.

Questions people ask

Is Diligent or Mimecast better?
Neither clearly leads. Diligent starts at On request and Mimecast at $4/month, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Diligent or Mimecast?
Diligent starts at On request and Mimecast at $4/month.
Does Diligent or Mimecast run on more platforms?
Diligent runs on Web, iOS, Android, Windows. Mimecast runs on Email, Cloud, Collaboration.
What is Diligent best used for?
Diligent is most often used for a listed company that wants board papers, entity records and the audit committee reporting pack produced from one governance system, an internal audit function moving from sampling to full-population transaction testing using the acl heritage analytics engine, a regulated firm consolidating a whistleblower hotline, third-party due diligence and policy attestation after an enforcement finding, a group needing sustainability disclosure data collected with the same audit trail and controls as financial reporting. Of those, a listed company that wants board papers, entity records and the audit committee reporting pack produced from one governance system and an internal audit function moving from sampling to full-population transaction testing using the acl heritage analytics engine are not what Mimecast is typically brought in for.
What can Diligent do that Mimecast cannot?
Diligent covers Diligent Boards, Entity management, Audit and analytics, Risk management. Mimecast covers Advanced threat detection, Secure sharing, Email encryption, Message tracking.

Answered from the vendors’ own pages

Diligent: Is Diligent One the same product as Galvanize?

It contains it. Diligent bought Galvanize, the ACL and Rsam merger, for around one billion dollars in April 2021, and its audit analytics and risk modules are that heritage rebranded into Diligent One.

Mimecast: How much does Mimecast cost?

Mimecast does not publish pricing on its website. Customers must request a custom quote by contacting the sales team at +1 617 393 7000 or using the Get a Quote button.

Source
Diligent: What does Diligent cost?

Not published. It is quoted by module and user, and board portal seats are priced differently from GRC seats. Expect an annual or multi-year enterprise agreement.

Mimecast: Is there a free trial of Mimecast?

Mimecast's trial and pricing options are not specified on the public website. Contact sales at +1 617 393 7000 or through their support portal at mimecastsupport.zendesk.com for trial availability.

Source
Diligent: Can you buy just the board portal?

Yes, Diligent Boards is sold on its own and is the most common entry point. The GRC modules are separate purchases.

Diligent: Does it replace a SOC 2 automation tool?

No. Diligent is aimed at enterprise audit, risk and governance, not at automated evidence collection for security certifications.

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